Tag Archives: artificial intelligence

Improving AWS Java applications with Amazon CodeGuru Reviewer

Post Syndicated from Rajdeep Mukherjee original https://aws.amazon.com/blogs/devops/improving-aws-java-applications-with-amazon-codeguru-reviewer/

Amazon CodeGuru Reviewer is a machine learning (ML)-based AWS service for providing automated code reviews comments on your Java and Python applications. Powered by program analysis and ML, CodeGuru Reviewer detects hard-to-find bugs and inefficiencies in your code and leverages best practices learned from across millions of lines of open-source and Amazon code. You can start analyzing your code through pull requests and full repository analysis (for more information, see Automating code reviews and application profiling with Amazon CodeGuru).

The recommendations generated by CodeGuru Reviewer for Java fall into the following categories:

  • AWS best practices
  • Concurrency
  • Security
  • Resource leaks
  • Other specialized categories such as sensitive information leaks, input validation, and code clones
  • General best practices on data structures, control flow, exception handling, and more

We expect the recommendations to benefit beginners as well as expert Java programmers.

In this post, we showcase CodeGuru Reviewer recommendations related to using the AWS SDK for Java. For in-depth discussion of other specialized topics, see our posts on concurrency, security, and resource leaks. For Python applications, see Raising Python code quality using Amazon CodeGuru.

The AWS SDK for Java simplifies the use of AWS services by providing a set of features that are consistent and familiar for Java developers. The SDK has more than 250 AWS service clients, which are available on GitHub. Service clients include services like Amazon Simple Storage Service (Amazon S3), Amazon DynamoDB, Amazon Kinesis, Amazon Elastic Compute Cloud (Amazon EC2), AWS IoT, and Amazon SageMaker. These services constitute more than 6,000 operations, which you can use to access AWS services. With such rich and diverse services and APIs, developers may not always be aware of the nuances of AWS API usage. These nuances may not be important at the beginning, but become critical as the scale increases and the application evolves or becomes diverse. This is why CodeGuru Reviewer has a category of recommendations: AWS best practices. This category of recommendations enables you to become aware of certain features of AWS APIs so your code can be more correct and performant.

The first part of this post focuses on the key features of the AWS SDK for Java as well as API patterns in AWS services. The second part of this post demonstrates using CodeGuru Reviewer to improve code quality for Java applications that use the AWS SDK for Java.

AWS SDK for Java

The AWS SDK for Java supports higher-level abstractions for simplified development and provides support for cross-cutting concerns such as credential management, retries, data marshaling, and serialization. In this section, we describe a few key features that are supported in the AWS SDK for Java. Additionally, we discuss some key API patterns such as batching, and pagination, in AWS services.

The AWS SDK for Java has the following features:

  • Waiters Waiters are utility methods that make it easy to wait for a resource to transition into a desired state. Waiters makes it easier to abstract out the polling logic into a simple API call. The waiters interface provides a custom delay strategy to control the sleep time between retries, as well as a custom condition on whether polling of a resource should be retried. The AWS SDK for Java also offer an async variant of waiters.
  • Exceptions The AWS SDK for Java uses runtime (or unchecked) exceptions instead of checked exceptions in order to give you fine-grained control over the errors you want to handle and to prevent scalability issues inherent with checked exceptions in large applications. Broadly, the AWS SDK for Java has two types of exceptions:
    • AmazonClientException – Indicates that a problem occurred inside the Java client code, either while trying to send a request to AWS or while trying to parse a response from AWS. For example, the AWS SDK for Java throws an AmazonClientException if no network connection is available when you try to call an operation on one of the clients.
    • AmazonServiceException – Represents an error response from an AWS service. For example, if you try to end an EC2 instance that doesn’t exist, Amazon EC2 returns an error response, and all the details of that response are included in the AmazonServiceException that’s thrown. For some cases, a subclass of AmazonServiceException is thrown to allow you fine-grained control over handling error cases through catch blocks.

The API has the following patterns:

  • Batching – A batch operation provides you with the ability to perform a single CRUD operation (create, read, update, delete) on multiple resources. Some typical use cases include the following:
  • Pagination – Many AWS operations return paginated results when the response object is too large to return in a single response. To enable you to perform pagination, the request and response objects for many service clients in the SDK provide a continuation token (typically named NextToken) to indicate additional results.

AWS best practices

Now that we have summarized the SDK-specific features and API patterns, let’s look at the CodeGuru Reviewer recommendations on AWS API use.

The CodeGuru Reviewer recommendations for the AWS SDK for Java range from detecting outdated or deprecated APIs to warning about API misuse, missing pagination, authentication and exception scenarios, and using efficient API alternatives. In this section, we discuss a few examples patterned after real code.

Handling pagination

Over 1,000 APIs from more than 150 AWS services have pagination operations. The pagination best practice rule in CodeGuru covers all the pagination operations. In particular, the pagination rule checks if the Java application correctly fetches all the results of the pagination operation.

The response of a pagination operation in AWS SDK for Java 1.0 contains a token that has to be used to retrieve the next page of results. In the following code snippet, you make a call to listTables(), a DynamoDB ListTables operation, which can only return up to 100 table names per page. This code might not produce complete results because the operation returns paginated results instead of all results.

public void getDynamoDbTable() {
        AmazonDynamoDBClient client = new AmazonDynamoDBClient();
        List<String> tables = dynamoDbClient.listTables().getTableNames();
        System.out.println(tables)
}

CodeGuru Reviewer detects the missing pagination in the code snippet and makes the following recommendation to add another call to check for additional results.

Screenshot of recommendations for introducing pagination checks

You can accept the recommendation and add the logic to get the next page of table names by checking if a token (LastEvaluatedTableName in ListTablesResponse) is included in each response page. If such a token is present, it’s used in a subsequent request to fetch the next page of results. See the following code:

public void getDynamoDbTable() {
        AmazonDynamoDBClient client = new AmazonDynamoDBClient();
        ListTablesRequest listTablesRequest = ListTablesRequest.builder().build();
        boolean done = false;
        while (!done) {
            ListTablesResponse listTablesResponse = client.listTables(listTablesRequest);
	    System.out.println(listTablesResponse.tableNames());
            if (listTablesResponse.lastEvaluatedTableName() == null) {
                done = true;
            }
            listTablesRequest = listTablesRequest.toBuilder()
                    .exclusiveStartTableName(listTablesResponse.lastEvaluatedTableName())
                    .build();
        }
}

Handling failures in batch operation calls

Batch operations are common with many AWS services that process bulk requests. Batch operations can succeed without throwing exceptions even if some items in the request fail. Therefore, a recommended practice is to explicitly check for any failures in the result of the batch APIs. Over 40 APIs from more than 20 AWS services have batch operations. The best practice rule in CodeGuru Reviewer covers all the batch operations. In the following code snippet, you make a call to sendMessageBatch, a batch operation from Amazon SQS, but it doesn’t handle any errors returned by that batch operation:

public void flush(final String sqsEndPoint,
                     final List<SendMessageBatchRequestEntry> batch) {
    AwsSqsClientBuilder awsSqsClientBuilder;
    AmazonSQS sqsClient = awsSqsClientBuilder.build();
    if (batch.isEmpty()) {
        return;
    }
    sqsClient.sendMessageBatch(sqsEndPoint, batch);
}

CodeGuru Reviewer detects this issue and makes the following recommendation to check the return value for failures.

Screenshot of recommendations for batch operations

You can accept this recommendation and add logging for the complete list of messages that failed to send, in addition to throwing an SQSUpdateException. See the following code:

public void flush(final String sqsEndPoint,
                     final List<SendMessageBatchRequestEntry> batch) {
    AwsSqsClientBuilder awsSqsClientBuilder;
    AmazonSQS sqsClient = awsSqsClientBuilder.build();
    if (batch.isEmpty()) {
        return;
    }
    SendMessageBatchResult result = sqsClient.sendMessageBatch(sqsEndPoint, batch);
    final List<BatchResultErrorEntry> failed = result.getFailed();
    if (!failed.isEmpty()) {
           final String failedMessage = failed.stream()
                         .map(batchResultErrorEntry -> 
                            String.format("…", batchResultErrorEntry.getId(), 
                            batchResultErrorEntry.getMessage()))
                         .collect(Collectors.joining(","));
           throw new SQSUpdateException("Error occurred while sending 
                                        messages to SQS::" + failedMessage);
    }
}

Exception handling best practices

Amazon S3 is one of the most popular AWS services with our customers. A frequent operation with this service is to upload a stream-based object through an Amazon S3 client. Stream-based uploads might encounter occasional network connectivity or timeout issues, and the best practice to address such a scenario is to properly handle the corresponding ResetException error. ResetException extends SdkClientException, which subsequently extends AmazonClientException. Consider the following code snippet, which lacks such exception handling:

private void uploadInputStreamToS3(String bucketName, 
                                   InputStream input, 
                                   String key, ObjectMetadata metadata) 
                         throws SdkClientException {
    final AmazonS3Client amazonS3Client;
    PutObjectRequest putObjectRequest =
          new PutObjectRequest(bucketName, key, input, metadata);
    amazonS3Client.putObject(putObjectRequest);
}

In this case, CodeGuru Reviewer correctly detects the missing handling of the ResetException error and suggests possible solutions.

Screenshot of recommendations for handling exceptions

This recommendation is rich in that it provides alternatives to suit different use cases. The most common handling uses File or FileInputStream objects, but in other cases explicit handling of mark and reset operations are necessary to reliably avoid a ResetException.

You can fix the code by explicitly setting a predefined read limit using the setReadLimit method of RequestClientOptions. Its default value is 128 KB. Setting the read limit value to one byte greater than the size of stream reliably avoids a ResetException.

For example, if the maximum expected size of a stream is 100,000 bytes, set the read limit to 100,001 (100,000 + 1) bytes. The mark and reset always work for 100,000 bytes or less. However, this might cause some streams to buffer that number of bytes into memory.

The fix reliably avoids ResetException when uploading an object of type InputStream to Amazon S3:

private void uploadInputStreamToS3(String bucketName, InputStream input, 
                                   String key, ObjectMetadata metadata) 
                             throws SdkClientException {
        final AmazonS3Client amazonS3Client;
        final Integer READ_LIMIT = 10000;
        PutObjectRequest putObjectRequest =
   			new PutObjectRequest(bucketName, key, input, metadata);  
        putObjectRequest.getRequestClientOptions().setReadLimit(READ_LIMIT);
        amazonS3Client.putObject(putObjectRequest);
}

Replacing custom polling with waiters

A common activity when you’re working with services that are eventually consistent (such as DynamoDB) or have a lead time for creating resources (such as Amazon EC2) is to wait for a resource to transition into a desired state. The AWS SDK provides the Waiters API, a convenient and efficient feature for waiting that abstracts out the polling logic into a simple API call. If you’re not aware of this feature, you might come up with a custom, and potentially inefficient polling logic to determine whether a particular resource had transitioned into a desired state.

The following code appears to be waiting for the status of EC2 instances to change to shutting-down or terminated inside a while (true) loop:

private boolean terminateInstance(final String instanceId, final AmazonEC2 ec2Client)
    throws InterruptedException {
    long start = System.currentTimeMillis();
    while (true) {
        try {
            DescribeInstanceStatusResult describeInstanceStatusResult = 
                            ec2Client.describeInstanceStatus(new DescribeInstanceStatusRequest()
                            .withInstanceIds(instanceId).withIncludeAllInstances(true));
            List<InstanceStatus> instanceStatusList = 
                       describeInstanceStatusResult.getInstanceStatuses();
            long finish = System.currentTimeMillis();
            long timeElapsed = finish - start;
            if (timeElapsed > INSTANCE_TERMINATION_TIMEOUT) {
                break;
            }
            if (instanceStatusList.size() < 1) {
                Thread.sleep(WAIT_FOR_TRANSITION_INTERVAL);
                continue;
            }
            currentState = instanceStatusList.get(0).getInstanceState().getName();
            if ("shutting-down".equals(currentState) || "terminated".equals(currentState)) {
                return true;
             } else {
                 Thread.sleep(WAIT_FOR_TRANSITION_INTERVAL);
             }
        } catch (AmazonServiceException ex) {
            throw ex;
        }
        …
 }

CodeGuru Reviewer detects the polling scenario and recommends you use the waiters feature to help improve efficiency of such programs.

Screenshot of recommendations for introducing waiters feature

Based on the recommendation, the following code uses the waiters function that is available in the AWS SDK for Java. The polling logic is replaced with the waiters() function, which is then run with the call to waiters.run(…), which accepts custom provided parameters, including the request and optional custom polling strategy. The run function polls synchronously until it’s determined that the resource transitioned into the desired state or not. The SDK throws a WaiterTimedOutException if the resource doesn’t transition into the desired state even after a certain number of retries. The fixed code is more efficient, simple, and abstracts the polling logic to determine whether a particular resource had transitioned into a desired state into a simple API call:

public void terminateInstance(final String instanceId, final AmazonEC2 ec2Client)
    throws InterruptedException {
    Waiter<DescribeInstancesRequest> waiter = ec2Client.waiters().instanceTerminated();
    ec2Client.terminateInstances(new TerminateInstancesRequest().withInstanceIds(instanceId));
    try {
        waiter.run(new WaiterParameters()
              .withRequest(new DescribeInstancesRequest()
              .withInstanceIds(instanceId))
              .withPollingStrategy(new PollingStrategy(new MaxAttemptsRetryStrategy(60), 
                    new FixedDelayStrategy(5))));
    } catch (WaiterTimedOutException e) {
        List<InstanceStatus> instanceStatusList = ec2Client.describeInstanceStatus(
               new DescribeInstanceStatusRequest()
                        .withInstanceIds(instanceId)
                        .withIncludeAllInstances(true))
                        .getInstanceStatuses();
        String state;
        if (instanceStatusList != null && instanceStatusList.size() > 0) {
            state = instanceStatusList.get(0).getInstanceState().getName();
        }
    }
}

Service-specific best practice recommendations

In addition to the SDK operation-specific recommendations in the AWS SDK for Java we discussed, there are various AWS service-specific best practice recommendations pertaining to service APIs for services such as Amazon S3, Amazon EC2, DynamoDB, and more, where CodeGuru Reviewer can help to improve Java applications that use AWS service clients. For example, CodeGuru can detect the following:

  • Resource leaks in Java applications that use high-level libraries, such as the Amazon S3 TransferManager
  • Deprecated methods in various AWS services
  • Missing null checks on the response of the GetItem API call in DynamoDB
  • Missing error handling in the output of the PutRecords API call in Kinesis
  • Anti-patterns such as binding the SNS subscribe or createTopic operation with Publish operation

Conclusion

This post introduced how to use CodeGuru Reviewer to improve the use of the AWS SDK in Java applications. CodeGuru is now available for you to try. For pricing information, see Amazon CodeGuru pricing.

Amazon Lex Introduces an Enhanced Console Experience and New V2 APIs

Post Syndicated from Martin Beeby original https://aws.amazon.com/blogs/aws/amazon-lex-enhanced-console-experience/

Today, the Amazon Lex team has released a new console experience that makes it easier to build, deploy, and manage conversational experiences. Along with the new console, we have also introduced new V2 APIs, including continuous streaming capability. These improvements allow you to reach new audiences, have more natural conversations, and develop and iterate faster.

The new Lex console and V2 APIs make it easier to build and manage bots focusing on three main benefits. First, you can add a new language to a bot at any time and manage all the languages through the lifecycle of design, test, and deployment as a single resource. The new console experience allows you to quickly move between different languages to compare and refine your conversations. I’ll demonstrate later how easy it was to add French to my English bot.

Second, V2 APIs simplify versioning. The new Lex console and V2 APIs provide a simple information architecture where the bot intents and slot types are scoped to a specific language. Versioning is performed at the bot level so that resources such as intents and slot types do not have to be versioned individually. All resources within the bot (language, intents, and slot types) are archived as part of the bot version creation. This new way of working makes it easier to manage bots.

Lastly, you have additional builder productivity tools and capabilities to give you more flexibility and control of your bot design process. You can now save partially completed work as you develop different bot elements as you script, test and tune your configuration. This provides you with more flexibility as you iterate through the bot development. For example, you can save a slot that refers to a deleted slot type. In addition to saving partially completed work, you can quickly navigate across the configuration without getting lost. The new Conversation flow capability allows you to maintain your orientation as you move across the different intents and slot types.

In addition to the enhanced console and APIs, we are providing a new streaming conversation API. Natural conversations are punctuated with pauses and interruptions. For example, a customer may ask to pause the conversation or hold the line while looking up the necessary information before answering a question to retrieve credit card details when providing bill payments. With streaming conversation APIs, you can pause a conversation and handle interruptions directly as you configure the bot. Overall, the design and implementation of the conversation is simplified and easy to manage. The bot builder can quickly enhance the conversational capability of virtual contact center agents or smart assistants.

Let’s create a new bot and explore how some of Lex’s new console and streaming API features provide an improved bot building experience.

Building a bot
I head over to the new V2 Lex console and click on Create bot to start things off.

I select that I want to Start with an example and select the MakeAppointment example.

Over the years, I have spoken at many conferences, so I now offer to review talks that other community members are producing. Since these speakers are often in different time zones, it can be complicated to organize the various appointments for the different types of reviews that I offer. So I have decided to build a bot to streamline the process. I give my bot the name TalkReview and provide a description. I also select Create a role with basic Amazon Lex permissions and use this as my runtime role.

I must add at least one language to my bot, so I start with English (GB). I also select the text-to-speech voice that I want to use should my bot require voice interaction rather than just text.

During the creation, there is a new button that allows me to Add another language. I click on this to add French (FR) to my bot. You can add languages during creation as I am doing here, or you can add additional languages later on as your bot becomes more popular and needs to work with new audiences.

I can now start defining intents for my bot, and I can begin the iterative process of building and testing my bot. I won’t go into all of the details of how to create a bot or show you all of the intents I added, as we have better tutorials that can show you that step-by-step, but I will point out a few new features that make this new enhanced console really compelling.

The new Conversation flow provides you with a visual flow of the conversation, and you can see how the sample utterances you provide and how your conversation might work in the real world. I love this feature because you can click on the various elements, and it will take you to where you can make changes. For example, I can click on the prompt What type of review would you like to schedule and I am taken to the place where I can edit this prompt.

The new console has a very well thought-out approach to versioning a bot. At anytime, on the Bot versions screen, I can click Create version, and it will take a snapshot of the state of the bot’s current configuration. I can then associate that with an alias. For example, in my application, I have an alias called Production. This Production alias is associated with Version 1. Still, at any time, I could switch it to use a different version or even roll back to a previous version if I discover problems.

The testing experience is now very streamlined. Once I have built the bot, I can click the test button on the bottom right hand of the screen and start speaking to the bot and testing the experience. You can also expand the Inspect window, which gives you details about the conversations state, and you can also explore the raw JSON inputs and outputs.

Things to know
Here are a couple of important things to keep in mind when you use the enhanced console

  • Integration with Amazon Connect – Currently, bots built in the new console cannot be integrated with Amazon Connect contact flows. We plan to provide this integration as part of the near-term roadmap. You can use the current console and existing APIs to create and integrate bots with Amazon Connect.
  • Pricing – You only pay for what you use. The charges remain the same for existing audio and text APIs, renamed as RecognizeUtterance and RecognizeText. For the new Streaming capabilities, please refer to the pricing detail here.
  • All existing APIs and bots will continue to be supported. The newly announced features are only available in the new console and V2 APIs.

Go Build
Lex enhanced console is available now, and you can start using it today. The enhanced experience and V2 APIs are available in all existing regions and support all current languages. So, please give this console a try and let us know what you think. To learn more, check out the documentation for the console and the streaming API.

Happy Building!
— Martin

Raspberry Pi LEGO sorter

Post Syndicated from Ashley Whittaker original https://www.raspberrypi.org/blog/raspberry-pi-lego-sorter/

Raspberry Pi is at the heart of this AI–powered, automated sorting machine that is capable of recognising and sorting any LEGO brick.

And its maker Daniel West believes it to be the first of its kind in the world!

Best ever

This mega-machine was two years in the making and is a LEGO creation itself, built from over 10,000 LEGO bricks.

A beast of 10,000 bricks

It can sort any LEGO brick you place in its input bucket into one of 18 output buckets, at the rate of one brick every two seconds.

While Daniel was inspired by previous LEGO sorters, his creation is a huge step up from them: it can recognise absolutely every LEGO brick ever created, even bricks it has never seen before. Hence the ‘universal’ in the name ‘universal LEGO sorting machine’.

Hardware

There we are, tucked away, just doing our job

Software

The artificial intelligence algorithm behind the LEGO sorting is a convolutional neural network, the go-to for image classification.

What makes Daniel’s project a ‘world first’ is that he trained his classifier using 3D model images of LEGO bricks, which is how the machine can classify absolutely any LEGO brick it’s faced with, even if it has never seen it in real life before.

We LOVE a thorough project video, and we love TWO of them even more

Daniel has made a whole extra video (above) explaining how the AI in this project works. He shouts out all the open source software he used to run the Raspberry Pi Camera Module and access 3D training images etc. at this point in the video.

LEGO brick separation

The vibration plate in action, feeding single parts into the scanner

Daniel needed the input bucket to carefully pick out a single LEGO brick from the mass he chucks in at once.

This is achieved with a primary and secondary belt slowly pushing parts onto a vibration plate. The vibration plate uses a super fast LEGO motor to shake the bricks around so they aren’t sitting on top of each other when they reach the scanner.

Scanning and sorting

A side view of the LEFO sorting machine showing a large white chute built from LEGO bricks
The underside of the beast

A Raspberry Pi Camera Module captures video of each brick, which Raspberry Pi 3 Model B+ then processes and wirelessly sends to a more powerful computer able to run the neural network that classifies the parts.

The classification decision is then sent back to the sorting machine so it can spit the brick, using a series of servo-controlled gates, into the right output bucket.

Extra-credit homework

A front view of the LEGO sorter with the sorting boxes visible underneath
In all its bricky beauty, with the 18 output buckets visible at the bottom

Daniel is such a boss maker that he wrote not one, but two further reading articles for those of you who want to deep-dive into this mega LEGO creation:

The post Raspberry Pi LEGO sorter appeared first on Raspberry Pi.

Resource leak detection in Amazon CodeGuru Reviewer

Post Syndicated from Pranav Garg original https://aws.amazon.com/blogs/devops/resource-leak-detection-in-amazon-codeguru/

This post discusses the resource leak detector for Java in Amazon CodeGuru Reviewer. CodeGuru Reviewer automatically analyzes pull requests (created in supported repositories such as AWS CodeCommit, GitHub, GitHub Enterprise, and Bitbucket) and generates recommendations for improving code quality. For more information, see Automating code reviews and application profiling with Amazon CodeGuru. This blog does not describe the resource leak detector for Python programs that is now available in preview.

What are resource leaks?

Resources are objects with a limited availability within a computing system. These typically include objects managed by the operating system, such as file handles, database connections, and network sockets. Because the number of such resources in a system is limited, they must be released by an application as soon as they are used. Otherwise, you will run out of resources and you won’t be able to allocate new ones. The paradigm of acquiring a resource and releasing it is also followed by other categories of objects such as metric wrappers and timers.

Resource leaks are bugs that arise when a program doesn’t release the resources it has acquired. Resource leaks can lead to resource exhaustion. In the worst case, they can cause the system to slow down or even crash.

Starting with Java 7, most classes holding resources implement the java.lang.AutoCloseable interface and provide a close() method to release them. However, a close() call in source code doesn’t guarantee that the resource is released along all program execution paths. For example, in the following sample code, resource r is acquired by calling its constructor and is closed along the path corresponding to the if branch, shown using green arrows. To ensure that the acquired resource doesn’t leak, you must also close r along the path corresponding to the else branch (the path shown using red arrows).

A resource must be closed along all execution paths to prevent resource leaks

Often, resource leaks manifest themselves along code paths that aren’t frequently run, or under a heavy system load, or after the system has been running for a long time. As a result, such leaks are latent and can remain dormant in source code for long periods of time before manifesting themselves in production environments. This is the primary reason why resource leak bugs are difficult to detect or replicate during testing, and why automatically detecting these bugs during pull requests and code scans is important.

Detecting resource leaks in CodeGuru Reviewer

For this post, we consider the following Java code snippet. In this code, method getConnection() attempts to create a connection in the connection pool associated with a data source. Typically, a connection pool limits the maximum number of connections that can remain open at any given time. As a result, you must close connections after their use so as to not exhaust this limit.

 1     private Connection getConnection(final BasicDataSource dataSource, ...)
               throws ValidateConnectionException, SQLException {
 2         boolean connectionAcquired = false;
 3         // Retrying three times to get the connection.
 4         for (int attempt = 0; attempt < CONNECTION_RETRIES; ++attempt) {
 5             Connection connection = dataSource.getConnection();
 6             // validateConnection may throw ValidateConnectionException
 7             if (! validateConnection(connection, ...)) {
 8                 // connection is invalid
 9                 DbUtils.closeQuietly(connection);
10             } else {
11                 // connection is established
12                 connectionAcquired = true;
13                 return connection;
14             }
15         }
16         return null;
17     }

At first glance, it seems that the method getConnection() doesn’t leak connection resources. If a valid connection is established in the connection pool (else branch on line 10 is taken), the method getConnection() returns it to the client for use (line 13). If the connection established is invalid (if branch on line 7 is taken), it’s closed in line 9 before another attempt is made to establish a connection.

However, method validateConnection() at line 7 can throw a ValidateConnectionException. If this exception is thrown after a connection is established at line 5, the connection is neither closed in this method nor is it returned upstream to the client to be closed later. Furthermore, if this exceptional code path runs frequently, for instance, if the validation logic throws on a specific recurring service request, each new request causes a connection to leak in the connection pool. Eventually, the client can’t acquire new connections to the data source, impacting the availability of the service.

A typical recommendation to prevent resource leak bugs is to declare the resource objects in a try-with-resources statement block. However, we can’t use try-with-resources to fix the preceding method because this method is required to return an open connection for use in the upstream client. The CodeGuru Reviewer recommendation for the preceding code snippet is as follows:

“Consider closing the following resource: connection. The resource is referenced at line 7. The resource is closed at line 9. The resource is returned at line 13. There are other execution paths that don’t close the resource or return it, for example, when validateConnection throws an exception. To prevent this resource leak, close connection along these other paths before you exit this method.”

As mentioned in the Reviewer recommendation, to prevent this resource leak, you must close the established connection when method validateConnection() throws an exception. This can be achieved by inserting the validation logic (lines 7–14) in a try block. In the finally block associated with this try, the connection must be closed by calling DbUtils.closeQuietly(connection) if connectionAcquired == false. The method getConnection() after this fix has been applied is as follows:

private Connection getConnection(final BasicDataSource dataSource, ...) 
        throws ValidateConnectionException, SQLException {
    boolean connectionAcquired = false;
    // Retrying three times to get the connection.
    for (int attempt = 0; attempt < CONNECTION_RETRIES; ++attempt) {
        Connection connection = dataSource.getConnection();
        try {
            // validateConnection may throw ValidateConnectionException
            if (! validateConnection(connection, ...)) {
                // connection is invalid
                DbUtils.closeQuietly(connection);
            } else {
                // connection is established
                connectionAcquired = true;
                return connection;
            }
        } finally {
            if (!connectionAcquired) {
                DBUtils.closeQuietly(connection);
            }
        }
    }
    return null;
}

As shown in this example, resource leaks in production services can be very disruptive. Furthermore, leaks that manifest along exceptional or less frequently run code paths can be hard to detect or replicate during testing and can remain dormant in the code for long periods of time before manifesting themselves in production environments. With the resource leak detector, you can detect such leaks on objects belonging to a large number of popular Java types such as file streams, database connections, network sockets, timers and metrics, etc.

Combining static code analysis with machine learning for accurate resource leak detection

In this section, we dive deep into the inner workings of the resource leak detector. The resource leak detector in CodeGuru Reviewer uses static analysis algorithms and techniques. Static analysis algorithms perform code analysis without running the code. These algorithms are generally prone to high false positives (the tool might report correct code as having a bug). If the number of these false positives is high, it can lead to alarm fatigue and low adoption of the tool. As a result, the resource leak detector in CodeGuru Reviewer prioritizes precision over recall— the findings we surface are resource leaks with a high accuracy, though CodeGuru Reviewer could potentially miss some resource leak findings.

The main reason for false positives in static code analysis is incomplete information available to the analysis. CodeGuru Reviewer requires only the Java source files and doesn’t require all dependencies or the build artifacts. Not requiring the external dependencies or the build artifacts reduces the friction to perform automated code reviews. As a result, static analysis only has access to the code in the source repository and doesn’t have access to its external dependencies. The resource leak detector in CodeGuru Reviewer combines static code analysis with a machine learning (ML) model. This ML model is used to reason about external dependencies to provide accurate recommendations.

To understand the use of the ML model, consider again the code above for method getConnection() that had a resource leak. In the code snippet, a connection to the data source is established by calling BasicDataSource.getConnection() method, declared in the Apache Commons library. As mentioned earlier, we don’t require the source code of external dependencies like the Apache library for code analysis during pull requests. Without access to the code of external dependencies, a pure static analysis-driven technique doesn’t know whether the Connection object obtained at line 5 will leak, if not closed. Similarly, it doesn’t know that DbUtils.closeQuietly() is a library function that closes the connection argument passed to it at line 9. Our detector combines static code analysis with ML that learns patterns over such external function calls from a large number of available code repositories. As a result, our resource leak detector knows that the connection doesn’t leak along the following code path:

  • A connection is established on line 5
  • Method validateConnection() returns false at line 7
  • DbUtils.closeQuietly() is called on line 9

This suppresses the possible false warning. At the same time, the detector knows that there is a resource leak when the connection is established at line 5, and validateConnection() throws an exception at line 7 that isn’t caught.

When we run CodeGuru Reviewer on this code snippet, it surfaces only the second leak scenario and makes an appropriate recommendation to fix this bug.

The ML model used in the resource leak detector has been trained on a large number of internal Amazon and GitHub code repositories.

Responses to the resource leak findings

Although closing an open resource in code isn’t difficult, doing so properly along all program paths is important to prevent resource leaks. This can easily be overlooked, especially along exceptional or less frequently run paths. As a result, the resource leak detector in CodeGuru Reviewer has observed a relatively high frequency, and has alerted developers within Amazon to thousands of resource leaks before they hit production.

The resource leak detections have witnessed a high developer acceptance rate, and developer feedback towards the resource leak detector has been very positive. Some of the feedback from developers includes “Very cool, automated finding,” “Good bot :),” and “Oh man, this is cool.” Developers have also concurred that the findings are important and need to be fixed.

Conclusion

Resource leak bugs are difficult to detect or replicate during testing. They can impact the availability of production services. As a result, it’s important to automatically detect these bugs early on in the software development workflow, such as during pull requests or code scans. The resource leak detector in CodeGuru Reviewer combines static code analysis algorithms with ML to surface only the high confidence leaks. It has a high developer acceptance rate and has alerted developers within Amazon to thousands of leaks before those leaks hit production.

New for Amazon CodeGuru – Python Support, Security Detectors, and Memory Profiling

Post Syndicated from Danilo Poccia original https://aws.amazon.com/blogs/aws/new-for-amazon-codeguru-python-support-security-detectors-and-memory-profiling/

Amazon CodeGuru is a developer tool that helps you improve your code quality and has two main components:

  • CodeGuru Reviewer uses program analysis and machine learning to detect potential defects that are difficult to find in your code and offers suggestions for improvement.
  • CodeGuru Profiler collects runtime performance data from your live applications, and provides visualizations and recommendations to help you fine-tune your application performance.

Today, I am happy to announce three new features:

  • Python Support for CodeGuru Reviewer and Profiler (Preview) – You can now use CodeGuru to improve applications written in Python. Before this release, CodeGuru Reviewer could analyze Java code, and CodeGuru Profiler supported applications running on a Java virtual machine (JVM).
  • Security Detectors for CodeGuru Reviewer – A new set of detectors for CodeGuru Reviewer to identify security vulnerabilities and check for security best practices in your Java code.
  • Memory Profiling for CodeGuru Profiler – A new visualization of memory retention per object type over time. This makes it easier to find memory leaks and optimize how your application is using memory.

Let’s see these functionalities in more detail.

Python Support for CodeGuru Reviewer and Profiler (Preview)
Python Support for CodeGuru Reviewer is available in Preview and offers recommendations on how to improve the Python code of your applications in multiple categories such as concurrency, data structures and control flow, scientific/math operations, error handling, using the standard library, and of course AWS best practices.

You can now also use CodeGuru Profiler to collect runtime performance data from your Python applications and get visualizations to help you identify how code is running on the CPU and where time is consumed. In this way, you can detect the most expensive lines of code of your application. Focusing your tuning activities on those parts helps you reduce infrastructure cost and improve application performance.

Let’s see the CodeGuru Reviewer in action with some Python code. When I joined AWS eight years ago, one of the first projects I created was a Filesystem in Userspace (FUSE) interface to Amazon Simple Storage Service (S3) called yas3fs (Yet Another S3-backed File System). It was inspired by the more popular s3fs-fuse project but rewritten from scratch to implement a distributed cache synchronized by Amazon Simple Notification Service (SNS) notifications (now, thanks to the many contributors, it’s using S3 event notifications). It was also a good excuse for me to learn more about Python programming and S3. It’s a personal project that at the time made available as open source. Today, if you need a shared file system, you can use Amazon Elastic File System (EFS).

In the CodeGuru console, I associate the yas3fs repository. You can associate repositories from GitHub, including GitHub Enterprise Cloud and GitHub Enterprise Server, Bitbucket, or AWS CodeCommit.

After that, I can get a code review from CodeGuru in two ways:

  • Automatically, when I create a pull request. This is a great way to use it as you and your team are working on a code base.
  • Manually, creating a repository analysis to get a code review for all the code in one branch. This is useful to start using GodeGuru with an existing code base.

Since I just associated the whole repository, I go for a full analysis and write down the branch name to review (apologies, I was still using master at the time, now I use main for new projects).

After a few minutes, the code review is completed, and there are 14 recommendations. Not bad, but I can definitely improve the code. Here’s a few of the recommendations I get. I was using exceptions and global variables too much at the time.

Security Detectors for CodeGuru Reviewer
The new CodeGuru Reviewer Security Detector uses automated reasoning to analyze all code paths and find potential security issues deep in your Java code, even ones that span multiple methods and files and that may involve multiple sequences of operations. To build this detector, we used learning and best practices from Amazon’s 20+ years of experience.

The Security Detector is also identifying security vulnerabilities in the top 10 Open Web Application Security Project (OWASP) categories, such as weak hash encryption.

If the security detector discovers an issue, it offers a suggested remediation along with an explanation. In this way, it’s much easier to follow security best practices for AWS APIs, such as those for AWS Key Management Service (KMS) and Amazon Elastic Compute Cloud (EC2), and for common Java cryptography and TLS/SSL libraries.

With help from the security detector, security engineers can focus on architectural and application-specific security best-practices, and code reviewers can focus their attention on other improvements.

Memory Profiling for CodeGuru Profiler
For applications running on a JVM, CodeGuru Profiler can now show the Heap Summary, a consolidated view of memory retention during a time frame, tracking both overall sizes and number of objects per object type (such as String, int, char[], and custom types). These metrics are presented in a timeline graph, so that you can easily spot trends and peaks of memory utilization per object type.

Here are a couple of scenarios where this can help:

Memory Leaks – A constantly growing memory utilization curve for one or more object types may indicate a leak (intended here as unnecessary retention of memory objects by the application), possibly leading to out-of-memory errors and application crashes.

Memory Optimizations – Having a breakdown of memory utilization per object type is a step beyond traditional memory utilization monitoring, based solely on JVM-level metrics like total heap usage. By knowing that an unexpectedly high amount of memory has been associated with a specific object type, you can focus your analysis and optimization efforts on the parts of your application that are responsible for allocating and referencing objects of that type.

For example, here is a graph showing how memory is used by a Java application over an interval of time. Apart from the total capacity available and the used space, I can see how memory is being used by some specific object types, such as byte[], java.lang.UUID, and the entries of a java.util.LinkedHashMap. The continuous growth over time of the memory retained by these object types is suspicious. There is probably a memory leak I have to investigate.

In the table just below, I have a longer list of object types allocating memory on the heap. The first three are selected and for that reason are shown in the graph above. Here, I can inspect other object types and select them to see their memory usage over time. It looks like the three I already selected are the ones with more risk of being affected by a memory leak.

Available Now
These new features are available today in all regions where Amazon CodeGuru is offered. For more information, please see the AWS Regional Services table.

There are no pricing changes for Python support, security detectors, and memory profiling. You pay for what you use without upfront fees or commitments.

Learn more about Amazon CodeGuru and start using these new features today to improve the code quality of your applications.  

Danilo

Amazon SageMaker JumpStart Simplifies Access to Pre-built Models and Machine Learning Solutions

Post Syndicated from Julien Simon original https://aws.amazon.com/blogs/aws/amazon-sagemaker-jumpstart-simplifies-access-to-prebuilt-models-and-machine-learning-models/

Today, I’m extremely happy to announce the availability of Amazon SageMaker JumpStart, a capability of Amazon SageMaker that accelerates your machine learning workflows with one-click access to popular model collections (also known as “model zoos”), and to end-to-end solutions that solve common use cases.

In recent years, machine learning (ML) has proven to be a valuable technique in improving and automating business processes. Indeed, models trained on historical data can accurately predict outcomes across a wide range of industry segments: financial services, retail, manufacturing, telecom, life sciences, and so on. Yet, working with these models requires skills and experience that only a subset of scientists and developers have: preparing a dataset, selecting an algorithm, training a model, optimizing its accuracy, deploying it in production, and monitoring its performance over time.

In order to simplify the model building process, the ML community has created model zoos, that is to say, collections of models built with popular open source libraries, and often pretrained on reference datasets. For example, the TensorFlow Hub and the PyTorch Hub provide developers with a long list of models ready to be downloaded, and integrated in applications for computer vision, natural language processing, and more.

Still, downloading a model is just part of the answer. Developers then need to deploy it for evaluation and testing, using either a variety of tools, such as the TensorFlow Serving and TorchServe model servers, or their own bespoke code. Once the model is running, developers need to figure out the correct format that incoming data should have, a long-lasting pain point. I’m sure I’m not the only one regularly pulling my hair out here!

Of course, a full-ML application usually has a lot of moving parts. Data needs to be preprocessed, enriched with additional data fetched from a backend, and funneled into the model. Predictions are often postprocessed, and stored for further analysis and visualization. As useful as they are, model zoos only help with the modeling part. Developers still have lots of extra work to deliver a complete ML solution.

Because of all this, ML experts are flooded with a long backlog of projects waiting to start. Meanwhile, less experienced practitioners struggle to get started. These barriers are incredibly frustrating, and our customers asked us to remove them.

Introducing Amazon SageMaker JumpStart
Amazon SageMaker JumpStart is integrated in Amazon SageMaker Studio, our fully integrated development environment (IDE) for ML, making it intuitive to discover models, solutions, and more. At launch, SageMaker JumpStart includes:

  • 15+ end-to-end solutions for common ML use cases such as fraud detection, predictive maintenance, and so on.
  • 150+ models from the TensorFlow Hub and the PyTorch Hub, for computer vision (image classification, object detection), and natural language processing (sentence classification, question answering).
  • Sample notebooks for the built-in algorithms available in Amazon SageMaker.

SageMaker JumpStart also provides notebooks, blogs, and video tutorials designed to help you learn and remove roadblocks. Content is easily accessible within Amazon SageMaker Studio, enabling you to get started with ML faster.

It only takes a single click to deploy solutions and models. All infrastructure is fully managed, so all you have to do is enjoy a nice cup of tea or coffee while deployment takes place. After a few minutes, you can start testing, thanks to notebooks and sample prediction code that are readily available in Amazon SageMaker Studio. Of course, you can easily modify them to use your own data.

SageMaker JumpStart makes it extremely easy for experienced practitioners and beginners alike to quickly deploy and evaluate models and solutions, saving days or even weeks of work. By drastically shortening the path from experimentation to production, SageMaker JumpStart accelerates ML-powered innovation, particularly for organizations and teams that are early on their ML journey, and haven’t yet accumulated a lot of skills and experience.

Now, let me show you how SageMaker JumpStart works.

Deploying a Solution with Amazon SageMaker JumpStart
Opening SageMaker Studio, I select the “JumpStart” icon on the left. This opens a new tab showing me all available content (solutions, models, and so on).

Let’s say that I’m interested in using computer vision to detect defects in manufactured products. Could ML be the answer?

Browsing the list of available solutions, I see one for product defect detection.

Opening it, I can learn more about the type of problems that it solves, the sample dataset used in the demo, the AWS services involved, and more.

SageMaker screenshot

A single click is all it takes to deploy this solution. Under the hood, AWS CloudFormation uses a built-in template to provision all appropriate AWS resources.

A few minutes later, the solution is deployed, and I can open its notebook.

SageMaker screenshot

The notebook opens immediately in SageMaker Studio. I run the demo, and understand how ML can help me detect product defects. This is also a nice starting point for my own project, making it easy to experiment with my own dataset (feel free to click on the image below to zoom in).

SageMaker screenshot

Once I’m done with this solution, I can delete all its resources in one click, letting AWS CloudFormation clean up without having to worry about leaving idle AWS resources behind.

SageMaker screenshot

Now, let’s look at models.

Deploying a Model with Amazon SageMaker JumpStart
SageMaker JumpStart includes a large collection of models available in the TensorFlow Hub and the PyTorch Hub. These models are pre-trained on reference datasets, and you can use them directly to handle a wide range of computer vision and natural language processing tasks. You can also fine-tune them on your own datasets for greater accuracy, a technique called transfer learning.

SageMaker screenshot
Here, I pick a version of the BERT model trained on question answering. I can either deploy it as is, or fine-tune it. For the sake of brevity, I go with the former here, and I just click on the “Deploy” button.

SageMaker screenshot

A few minutes later, the model has been deployed to a real-time endpoint powered by fully managed infrastructure.

SageMaker screenshot

Time to test it! Clicking on “Open Notebook” launches a sample notebook that I run right away to test the model, without having to change a line of code (again, feel free to click on the image below to zoom in). Here, I’m asking two questions (“What is Southern California often abbreviated as?” and “Who directed Spectre?“), passing some context containing the answer. In both cases, the BERT model gives the correct answer, respectively “socal” and “Sam Mendes“.

SageMaker screenshot

When I’m done testing, I can delete the endpoint in one click, and stop paying for it.

Getting Started
As you can see, it’s extremely easy to deploy models and solutions with SageMaker JumpStart in minutes, even if you have little or no ML skills.

You can start using this capability today in all regions where SageMaker Studio is available, at no additional cost.

Give it a try and let us know what you think.

As always, we’re looking forward to your feedback, either through your usual AWS support contacts, or on the AWS Forum for SageMaker.

– Julien

Special thanks to my colleague Jared Heywood for his precious help during early testing.

New – Amazon SageMaker Pipelines Brings DevOps Capabilities to your Machine Learning Projects

Post Syndicated from Julien Simon original https://aws.amazon.com/blogs/aws/amazon-sagemaker-pipelines-brings-devops-to-machine-learning-projects/

Today, I’m extremely happy to announce Amazon SageMaker Pipelines, a new capability of Amazon SageMaker that makes it easy for data scientists and engineers to build, automate, and scale end to end machine learning pipelines.

Machine learning (ML) is intrinsically experimental and unpredictable in nature. You spend days or weeks exploring and processing data in many different ways, trying to crack the geode open to reveal its precious gemstones. Then, you experiment with different algorithms and parameters, training and optimizing lots of models in search of highest accuracy. This process typically involves lots of different steps with dependencies between them, and managing it manually can become quite complex. In particular, tracking model lineage can be difficult, hampering auditability and governance. Finally, you deploy your top models, and you evaluate them against your reference test sets. Finally? Not quite, as you’ll certainly iterate again and again, either to try out new ideas, or simply to periodically retrain your models on new data.

No matter how exciting ML is, it does unfortunately involve a lot of repetitive work. Even small projects will require hundreds of steps before they get the green light for production. Over time, not only does this work detract from the fun and excitement of your projects, it also creates ample room for oversight and human error.

To alleviate manual work and improve traceability, many ML teams have adopted the DevOps philosophy and implemented tools and processes for Continuous Integration and Continuous Delivery (CI/CD). Although this is certainly a step in the right direction, writing your own tools often leads to complex projects that require more software engineering and infrastructure work than you initially anticipated. Valuable time and resources are diverted from the actual ML project, and innovation slows down. Sadly, some teams decide to revert to manual work, for model management, approval, and deployment.

Introducing Amazon SageMaker Pipelines
Simply put, Amazon SageMaker Pipelines brings in best-in-class DevOps practices to your ML projects. This new capability makes it easy for data scientists and ML developers to create automated and reliable end-to-end ML pipelines. As usual with SageMaker, all infrastructure is fully managed, and doesn’t require any work on your side.

Care.com is the world’s leading platform for finding and managing high-quality family care. Here’s what Clemens Tummeltshammer, Data Science Manager, Care.com, told us: “A strong care industry where supply matches demand is essential for economic growth from the individual family up to the nation’s GDP. We’re excited about Amazon SageMaker Feature Store and Amazon SageMaker Pipelines, as we believe they will help us scale better across our data science and development teams, by using a consistent set of curated data that we can use to build scalable end-to-end machine learning (ML) model pipelines from data preparation to deployment. With the newly announced capabilities of Amazon SageMaker, we can accelerate development and deployment of our ML models for different applications, helping our customers make better informed decisions through faster real-time recommendations.

Let me tell you more about the main components in Amazon SageMaker Pipelines: pipelines, model registry, and MLOps templates.

Pipelines – Model building pipelines are defined with a simple Python SDK. They can include any operation available in Amazon SageMaker, such as data preparation with Amazon SageMaker Processing or Amazon SageMaker Data Wrangler, model training, model deployment to a real-time endpoint, or batch transform. You can also add Amazon SageMaker Clarify to your pipelines, in order to detect bias prior to training, or once the model has been deployed. Likewise, you can add Amazon SageMaker Model Monitor to detect data and prediction quality issues.

Once launched, model building pipelines are executed as CI/CD pipelines. Every step is recorded, and detailed logging information is available for traceability and debugging purposes. Of course, you can also visualize pipelines in Amazon SageMaker Studio, and track their different executions in real time.

Model Registry – The model registry lets you track and catalog your models. In SageMaker Studio, you can easily view model history, list and compare versions, and track metadata such as model evaluation metrics. You can also define which versions may or may not be deployed in production. In fact, you can even build pipelines that automatically trigger model deployment once approval has been given. You’ll find that the model registry is very useful in tracing model lineage, improving model governance, and strengthening your compliance posture.

MLOps TemplatesSageMaker Pipelines includes a collection of built-in CI/CD templates for popular pipelines (build/train/deploy, deploy only, and so on). You can also add and publish your own templates, so that your teams can easily discover them and deploy them. Not only do templates save lots of time, they also make it easy for ML teams to collaborate from experimentation to deployment, using standard processes and without having to manage any infrastructure. Templates also let Ops teams customize steps as needed, and give them full visibility for troubleshooting.

Now, let’s do a quick demo!

Building an End-to-end Pipeline with Amazon SageMaker Pipelines
Opening SageMaker Studio, I select the “Components” tab and the “Projects” view. This displays a list of built-in project templates. I pick one to build, train, and deploy a model.

SageMaker screenshot

Then, I simply give my project a name, and create it.

A few seconds later, the project is ready. I can see that it includes two Git repositories hosted in AWS CodeCommit, one for model training, and one for model deployment.

SageMaker screenshot

The first repository provides scaffolding code to create a multi-step model building pipeline: data processing, model training, model evaluation, and conditional model registration based on accuracy. As you’ll see in the pipeline.py file, this pipeline trains a linear regression model using the XGBoost algorithm on the well-known Abalone dataset. This repository also includes a build specification file, used by AWS CodePipeline and AWS CodeBuild to execute the pipeline automatically.

Likewise, the second repository contains code and configuration files for model deployment, as well as test scripts required to pass the quality gate. This operation is also based on AWS CodePipeline and AWS CodeBuild, which run a AWS CloudFormation template to create model endpoints for staging and production.

Clicking on the two blue links, I clone the repositories locally. This triggers the first execution of the pipeline.

SageMaker screenshot

A few minutes later, the pipeline has run successfully. Switching to the “Pipelines” view, I can visualize its steps.

SageMaker screenshot

Clicking on the training step, I can see the Root Mean Square Error (RMSE) metrics for my model.

SageMaker screenshot

As the RMSE is lower than the threshold defined in the conditional step, my model is added to the model registry, as visible below.

SageMaker screenshot

For simplicity, the registration step sets the model status to “Approved”, which automatically triggers its deployment to a real-time endpoint in the same account. Within seconds, I see that the model is being deployed.

SageMaker screenshot

Alternatively, you could register your model with a “Pending manual approval” status. This will block deployment until the model has been reviewed and approved manually. As the model registry supports cross-account deployment, you could also easily deploy in a different account, without having to copy anything across accounts.

A few minutes later, the endpoint is up, and I could use it to test my model.

SageMaker screenshot

Once I’ve made sure that this model works as expected, I could ping the MLOps team, and ask them to deploy the model in production.

Putting my MLOps hat on, I open the AWS CodePipeline console, and I see that my deployment is indeed waiting for approval.

SageMaker screenshot

I then approve the model for deployment, which triggers the final stage of the pipeline.

SageMaker screenshot

Reverting to my Data Scientist hat, I see in SageMaker Studio that my model is being deployed. Job done!

SageMaker screenshot

Getting Started
As you can see, Amazon SageMaker Pipelines makes it really easy for Data Science and MLOps teams to collaborate using familiar tools. They can create and execute robust, automated ML pipelines that deliver high quality models in production quicker than before.

You can start using SageMaker Pipelines in all commercial regions where SageMaker is available. The MLOps capabilities are available in the regions where CodePipeline is also available.

Sample notebooks are available to get you started. Give them a try, and let us know what you think. We’re always looking forward to your feedback, either through your usual AWS support contacts, or on the AWS Forum for SageMaker.

– Julien

Special thanks to my colleague Urvashi Chowdhary for her precious assistance during early testing.

Introducing Amazon SageMaker Data Wrangler, a Visual Interface to Prepare Data for Machine Learning

Post Syndicated from Julien Simon original https://aws.amazon.com/blogs/aws/introducing-amazon-sagemaker-data-wrangler-a-visual-interface-to-prepare-data-for-machine-learning/

Today, I’m extremely happy to announce Amazon SageMaker Data Wrangler, a new capability of Amazon SageMaker that makes it faster for data scientists and engineers to prepare data for machine learning (ML) applications by using a visual interface.

Whenever I ask a group of data scientists and ML engineers how much time they actually spend studying ML problems, I often hear a collective sigh, followed by something along the lines of, “20%, if we’re lucky.” When I ask them why, the answer is invariably the same, “data preparation consistently takes up to 80% of our time!

Indeed, preparing data for training is a crucial step of the ML process, and no one would think about botching it up. Typical tasks include:

  • Locating data: finding where raw data is stored, and getting access to it
  • Data visualization: examining statistical properties for each column in the dataset, building histograms, studying outliers
  • Data cleaning: removing duplicates, dropping or filling entries with missing values, removing outliers
  • Data enrichment and feature engineering: processing columns to build more expressive features, selecting a subset of features for training

In the early stage of a new ML project, this is a highly manual process, where intuition and experience play a large part. Using a mix of bespoke tools and open source tools such as pandas or PySpark, data scientists often experiment with different combinations of data transformations, and use them to process datasets before training models. Then, they analyze prediction results and iterate. As important as this is, looping through this process again and again can be time-consuming, tedious, and error-prone.

At some point, you will hit the right level of accuracy (or whatever other metric you’ve picked), and you’ll then want to train on the full dataset in your production environment. However, you’ll first have to reproduce and automate the exact data preparation steps that you experimented within your sandbox. Unfortunately, there’s always room for error given the interactive nature of this work, even if you carefully document it.

Last but not least, you’ll have to manage and scale your data processing infrastructure before you get to the finish line. Now that I think of it, 80% of your time may not be enough to do all of this!

Introducing Amazon SageMaker Data Wrangler
Amazon SageMaker Data Wrangler is integrated in Amazon SageMaker Studio, our fully managed integrated development environment (IDE) for ML. With just a few clicks, you can connect to data sources, explore and visualize data, apply built-in transformations as well as your own, export the resulting code to an auto-generated script, and run it on managed infrastructure. Let’s look at each step in more detail.

Obviously, data preparation starts with locating and accessing data. Out of the box, SageMaker Data Wrangler lets you easily and quickly connect to Amazon Simple Storage Service (S3), Amazon Athena, Amazon Redshift and AWS Lake Formation. You can also import data from Amazon SageMaker Feature Store. As all things AWS, access management is governed by AWS Identity and Access Management (IAM), based on the permissions attached to your SageMaker Studio instance.

Once you’ve connected to your data sources, you’ll probably want to visualize your data. Using the SageMaker Data Wrangler user interface, you can view table summaries, histograms, and scatter plots in seconds. You can also build your own custom graphs by simply copying and running code written with the popular Altair open source library.

Once you’ve got a good grasp on what your data looks like, it’s time to start preparing it. SageMaker Data Wrangler includes 300+ built-in transformations, such as finding and replacing data, splitting/renaming/dropping columns, scaling numerical values, encoding categorical values, and so on. All you have to do is select the transformation in a drop-down list, and fill in the parameters it may require. You can then preview the change, and decide whether you’d like to add it or not to the list of preparation steps for this dataset. If you’d like, you can also add your own code to implement custom transformations, using either pandas, PySpark, or PySpark SQL.

As you add transformation steps to your processing pipeline, you can view its graphical summary in SageMaker Studio. You can also add new stages to the pipeline, for example a new data source, or another group of transformation steps (say, a data cleaning group, followed by a feature engineering group). Thanks to the intuitive user interface, your data preparation pipeline will take shape in front of your eyes, and you’ll instantly be able to check that processed data looks the way that it should.

Early on, you’d certainly love to check your data preparation steps, and also get a sense of their predictive power, wouldn’t you? Good news, then! For regression and classification problem types, the “Quick model” capability lets you select a subset of your data, train a model, and determine which features are contributing most to the predicted outcome. Looking at the model, you can easily diagnose and fix data preparation issues as early as possible, and to determine if additional feature engineering is needed to improve your model performance.

Once you’re happy with your pipeline, you can export it in one click to a Python script that faithfully reproduces your manual steps. You won’t waste any time chasing discrepancies, and you can directly add this code to your ML project.

In addition, you can also export your processing code to:

Now, let’s do a quick demo, and show you how easy it is to work with SageMaker Data Wrangler .

Using Amazon SageMaker Data Wrangler
Opening SageMaker Studio, I create a new data flow in order to process the Titanic dataset, which contains information on passengers, and labels showing whether they survived the wreck or not.

SageMaker screenshot

My dataset is stored as a CSV file in Amazon Simple Storage Service (S3), and I select the appropriate data source.

SageMaker screenshot

Using the built-in tool, I quickly navigate my S3 buckets, and I locate the CSV file containing my data. For larger datasets, SageMaker Data Wrangler also supports the Parquet format.

As I select my file, SageMaker Data Wrangler shows me the first few rows.

SageMaker screenshot

I import the dataset, and I’m presented with an initial view of the data flow. Right-clicking on the dataset, I select “Edit data types” to make sure that SageMaker Data Wrangler has correctly detected the type of each column in the dataset.

SageMaker screenshot

Checking each column, it looks like all types are correct.

SageMaker screenshot

Moving back to the data flow view, I select “Add analysis” this time. This opens a new view where I can visualize data using histograms, scatterplots, and more. For example, I build an histogram showing me the age distribution of passengers according to their survival status, and coloring the bins using their gender. Of course, I can save it for future use.

SageMaker screenshot

Moving back to the data flow view once again, I select “Add transform” in order to start processing the dataset. This opens a new view, showing me the first lines of the dataset, as well as a list of 300+ built-in transforms.

SageMaker screenshot

Pclass, the passenger class, is a categorical variable, and I decide to encode it using one-hot encoding. This creates 3 new columns representing different dimensions, and I can preview them. As this is exactly what I wanted, I apply this transform for good. Likewise, I apply the same transform to the Sex column.

SageMaker screenshot

Then, I drop the original Pclass column. Using the same transform, I also drop the Name column.

SageMaker screenshot

In order to get a quick idea on whether these transformations increase or decrease the accuracy of the model, I can create a analysis that trains a model on the spot. As my problem is a binary classification problem, SageMaker Data Wrangler uses a metric called the F1 score. 0.749 is a good start, and additional processing would certainly improve it. I can also see which features contribute most to the predicted outcome: sex, age, and being a third class passenger.

SageMaker screenshot

Then, moving to the “Export” view, I select all the transforms I’ve created so far, in order to add them to my ML project.

SageMaker screenshot

Here, I select “Python Code” to generate a Python script. Other options are available for Amazon SageMaker Processing, Amazon SageMaker Pipelines, and Amazon SageMaker Feature Store.

SageMaker screenshot

A few seconds later, the script is available. I could add it as is to my ML project, and rest assured that my data preparation steps would be consistent with the interactive transforms that I’ve created above.

SageMaker screenshot

Getting Started
As you can see, Amazon SageMaker Data Wrangler makes it really easy to work interactively on data preparation steps, before transforming them into code that can be used immediately for experimentation and production.

You can start using this capability today in all regions where SageMaker Studio is available.

Give it a try, and let us know what you think. We’re always looking forward to your feedback, either through your usual AWS support contacts, or on the AWS Forum for SageMaker.

– Julien

Special thanks to my colleague Peter Liu for his precious help during early testing.

New – Store, Discover, and Share Machine Learning Features with Amazon SageMaker Feature Store

Post Syndicated from Julien Simon original https://aws.amazon.com/blogs/aws/new-store-discover-and-share-machine-learning-features-with-amazon-sagemaker-feature-store/

Today, I’m extremely happy to announce Amazon SageMaker Feature Store, a new capability of Amazon SageMaker that makes it easy for data scientists and machine learning engineers to securely store, discover and share curated data used in training and prediction workflows.

For all the importance of selecting the right algorithm to train machine learning (ML) models, experienced practitioners know how crucial it is to feed it with high-quality data. Cleaning data is a good first step, and ML workflows routinely include steps to fill missing values, remove outliers, and so on. Then, they often move on to transforming data, using a mix of common and arcane techniques known as “feature engineering.”

Simply put, the purpose of feature engineering is to transform your data and to increase its expressiveness so that the algorithm may learn better. For instance, many columnar datasets include strings, such as street addresses. To most ML algorithms, strings are meaningless, and they need to be encoded in a numerical representation. Thus, you could replace street addresses with GPS coordinates, a much more expressive way to learn the concept of location. In other words, if data is the new oil, then feature engineering is the refining process that turns it into high-octane jet fuel that helps models get to stratospheric accuracy.

Indeed, ML practitioners spend a lot of time crafting feature engineering code, applying it to their initial datasets, training models on the engineered datasets, and evaluating model accuracy. Given the experimental nature of this work, even the smallest project will lead to multiple iterations. The same feature engineering code is often run again and again, wasting time and compute resources on repeating the same operations. In large organizations, this can cause an even greater loss of productivity, as different teams often run identical jobs, or even write duplicate feature engineering code because they have no knowledge of prior work.

There’s another hard problem that ML teams have to solve. As models are trained on engineered datasets, it’s imperative to apply the same transformations to data sent for prediction. This often means rewriting feature engineering code, sometimes in a different language, integrating it in your prediction workflow, and running it at prediction time. This whole process is not only time-consuming, it can also introduce inconsistencies, as even the tiniest variation in a data transform can have a large impact on predictions.

In order to solve these problems, ML teams sometimes build a feature store, a central repository where they can keep and retrieve engineered data used in their training and predictions jobs. As useful as feature stores are, building and managing your own involves a lot of engineering, infrastructure, and operational effort that takes valuable time away from actual ML work. Customers asked us for a better solution, and we got to work.

Introducing Amazon SageMaker Feature Store
Amazon SageMaker Feature Store is a fully managed centralized repository for your ML features, making it easy to securely store and retrieve features without having to manage any infrastructure. It’s part of Amazon SageMaker, our fully managed service for ML, and supports all algorithms. It’s also integrated with Amazon SageMaker Studio, our web-based development environment for ML.

Features stored in SageMaker Feature Store are organized in groups, and tagged with metadata. Thanks to this, you can quickly discover which features are available, and whether they’re suitable for your models. Multiple teams can also easily share and re-use features, reducing the cost of development and accelerating innovation.

Once stored, features can be retrieved and used in your SageMaker workflows: model training, batch transform, and real-time prediction with low latency. Not only do you avoid duplicating work, you also build consistent workflows that use the same consistent features stored in the offline and online stores.

The Climate Corporation (Climate) is a subsidiary of Bayer, and the industry leader in bringing digital innovation to farmers. Says Daniel McCaffrey, Vice President, Data and Analytics, Climate: “At Climate, we believe in providing the world’s farmers with accurate information to make data driven decisions and maximize their return on every acre. To achieve this, we have invested in technologies such as machine learning tools to build models using measurable entities known as features, such as yield for a grower’s field. With Amazon SageMaker Feature Store, we can accelerate the development of ML models with a central feature store to access and reuse features across multiple teams easily. SageMaker Feature Store makes it easy to access features in real-time using the online store, or run features on a schedule using the offline store for different use cases, and we can develop ML models faster.”

Care.com, the world’s leading platform for finding and managing high-quality family care, is also using Amazon SageMaker Feature Store. This is what Clemens Tummeltshammer, Data Science Manager, Care.com, told us: “A strong care industry where supply matches demand is essential for economic growth from the individual family up to the nation’s GDP. We’re excited about Amazon SageMaker Feature Store and Amazon SageMaker Pipelines , as we believe they will help us scale better across our data science and development teams, by using a consistent set of curated data that we can use to build scalable end-to-end machine learning model pipelines from data preparation to deployment. With the newly announced capabilities of Amazon SageMaker, we can accelerate development and deployment of our ML models for different applications, helping our customers make better informed decisions through faster real-time recommendations.

Now, let’s see how you can get started.

Storing and Retrieving Features with Amazon SageMaker Feature Store
Once you’ve run your feature engineering code on your data, you can organize and store your engineered features in SageMaker Feature Store, by grouping them in feature groups. A feature group is a collection of records, similar to rows in a table. Each record has a unique identifier, and holds the engineered feature values for one of the data instances in your original data source. Optionally, you can choose to encrypt the data at rest using your own AWS Key Management Service (KMS) key that is unique for each feature group.

How you define feature groups is up to you. For example, you could create one per data source (CSV files, database tables, and so on), and use a convenient unique column as the record identifier (primary key, customer id, transaction id, and so on).

Once you’ve got your groups figured out, you should repeat the following steps for each group:

  1. Create feature definitions, with the name and the type of each feature in a record (Fractional, Integral, or String).
  2. Create each feature group with the create_feature_group() API:
    sm_feature_store.create_feature_group(
         # The name of the feature group
         FeatureGroupName=my_feature_group_name,
         # The name of the column acting as the record identifier
         RecordIdentifierName=record_identifier_name,
         # The name of the column action as the feature timestamp
         EventTimeFeatureName = event_time_feature_name,
         # A list of feature names and types
         FeatureDefinitions=my_feature_definitions,
         # The S3 location for the offline feature store
         OnlineStoreConfig=online_store_config,
         # Optionally, enable the online feature store
         OfflineStoreConfig=offline_store_config,
         # An IAM role
         RoleArn=role
    )
  3. In each feature group, store records containing a collection of feature name/feature value pairs, using the put_record() API:
    sm_feature_store.put_record(
       FeatureGroupName=feature_group_name,
       Record=record,
       EventTime=event_time
    )

    For faster ingestion, you could create multiple threads and parallelize this operation.

At this point, features will be available in Amazon SageMaker Feature Store. Thanks to the offline store, you can use services such as Amazon Athena, AWS Glue, or Amazon EMR to build datasets for training: fetch the corresponding JSON objects in S3, select the features that you need, and save them in S3 in the format expected by your ML algorithm. From then on, it’s SageMaker business as usual!

In addition, you can use the get_record() API to access individual records stored in the online store, passing the group name and the unique identifier of the record you want to access, like so:

record = sm_feature_store.get_record(
    FeatureGroupName=my_feature_group_name,
    RecordIdentifierValue={"IntegralValue": 5962}
)

Amazon SageMaker Feature Store is designed for fast and efficient access for real time inference, with a P95 latency lower than 10ms for a 15-kilobyte payload. This makes it possible to query for engineered features at prediction time, and to replace raw features sent by the upstream application with the exact same features used to train the model. Feature inconsistencies are eliminated by design, letting you focus on building the best models instead of chasing bugs.

Finally, as SageMaker Feature Store includes feature creation timestamps, you can retrieve the state of your features at a particular point in time.

As Amazon SageMaker Feature Store is integrated with SageMaker Studio, I can see my two features groups there.

SageMaker screenshot

Right-clicking on “Open feature group detail”, I open the identity feature group.

SageMaker screenshot

I can see feature definitions.

SageMaker screenshot

Finally, I can generate queries for the offline store, which I could add to a Amazon SageMaker Data Wrangler workflow to load features prior to training.

SageMaker screenshot

How to Get Started with Amazon SageMaker Feature Store
As you can see, SageMaker Feature Store makes it easy to store, retrieve, and share features required by your training and prediction workflows.

SageMaker Feature Store is available in all regions where SageMaker is available. Pricing is based on feature reads and writes, and on the total amount of data stored.

Here are sample notebooks that will help you get started right away. Give them a try, and let us know what you think. We’re always looking forward to your feedback, either through your usual AWS support contacts, or on the AWS Forum for SageMaker.

– Julien

Amazon HealthLake Stores, Transforms, and Analyzes Health Data in the Cloud

Post Syndicated from Harunobu Kameda original https://aws.amazon.com/blogs/aws/new-amazon-healthlake-to-store-transform-and-analyze-petabytes-of-health-and-life-sciences-data-in-the-cloud/

Healthcare organizations collect vast amounts of patient information every day, from family history and clinical observations to diagnoses and medications. They use all this data to try to compile a complete picture of a patient’s health information in order to provide better healthcare services. Currently, this data is distributed across various systems (electronic medical records, laboratory systems, medical image repositories, etc.) and exists in dozens of incompatible formats.

Emerging standards, such as Fast Healthcare Interoperability Resources (FHIR), aim to address this challenge by providing a consistent format for describing and exchanging structured data across these systems. However, much of this data is unstructured information contained in medical records (e.g., clinical records), documents (e.g., PDF lab reports), forms (e.g., insurance claims), images (e.g., X-rays, MRIs), audio (e.g., recorded conversations), and time series data (e.g., heart electrocardiogram) and it is challenging to extract this information.

It can take weeks or months for a healthcare organization to collect all this data and prepare it for transformation (tagging and indexing), structuring, and analysis. Furthermore, the cost and operational complexity of doing all this work is prohibitive for most healthcare organizations.

Many data to analyze

Today, we are happy to announce Amazon HealthLake, a fully managed, HIPAA-eligible service, now in preview, that allows healthcare and life sciences customers to aggregate their health information from different silos and formats into a centralized AWS data lake. HealthLake uses machine learning (ML) models to normalize health data and automatically understand and extract meaningful medical information from the data so all this information can be easily searched. Then, customers can query and analyze the data to understand relationships, identify trends, and make predictions.

How It Works
Amazon HealthLake supports copying your data from on premises to the AWS Cloud, where you can store your structured data (like lab results) as well as unstructured data (like clinical notes), which HealthLake will tag and structure in FHIR. All the data is fully indexed using standard medical terms so you can quickly and easily query, search, analyze, and update all of your customers’ health information.

Overview of HealthLake

With HealthLake, healthcare organizations can collect and transform patient health information in minutes and have a complete view of a patients medical history, structured in the FHIR industry standard format with powerful search and query capabilities.

From the AWS Management Console, healthcare organizations can use the HealthLake API to copy their on-premises healthcare data to a secure data lake in AWS with just a few clicks. If your source system is not configured to send data in FHIR format, you can use a list of AWS partners to easily connect and convert your legacy healthcare data format to FHIR.

HealthLake is Powered by Machine Learning
HealthLake uses specialized ML models such as natural language processing (NLP) to automatically transform raw data. These models are trained to understand and extract meaningful information from unstructured health data.

For example, HealthLake can accurately identify patient information from medical histories, physician notes, and medical imaging reports. It then provides the ability to tag, index, and structure the transformed data to make it searchable by standard terms such as medical condition, diagnosis, medication, and treatment.

Queries on tens of thousands of patient records are very simple. For example, a healthcare organization can create a list of diabetic patients based on similarity of medications by selecting “diabetes” from the standard list of medical conditions, selecting “oral medications” from the treatment menu, and refining the gender and search.

Healthcare organizations can use Juypter Notebook templates in Amazon SageMaker to quickly and easily run analysis on the normalized data for common tasks like diagnosis predictions, hospital re-admittance probability, and operating room utilization forecasts. These models can, for example, help healthcare organizations predict the onset of disease. With just a few clicks in a pre-built notebook, healthcare organizations can apply ML to their historical data and predict when a diabetic patient will develop hypertension in the next five years. Operators can also build, train, and deploy their own ML models on data using Amazon SageMaker directly from the AWS management console.

Let’s Create Your Own Data Store and Start to Test
Starting to use HealthLake is simple. You access AWS Management Console, and click select Create a datastore.

If you click Preload data, HealthLake will load test data and you can start to test its features. You can also upload your own data if you already have FHIR 4 compliant data. You upload it to S3 buckets, and import it to set its bucket name.

Once your Data Store is created, you can perform a Search, Create, Read, Update or Delete FHIR Query Operation. For example, if you need a list of every patient located in New York, your query setting looks like the screenshots below. As per the FHIR specification, deleted data is only hidden from analysis and results; it is not deleted from the service, only versioned.

Creating Query

 

You can choose Add search parameter for more nested conditions of the query as shown below.

Amazon HealthLake is Now in Preview
Amazon HealthLake is in preview starting today in US East (N. Virginia). Please check our web site and technical documentation for more information.

– Kame

Bringing machine learning to more builders through databases and analytics services

Post Syndicated from Swami Sivasubramanian original https://aws.amazon.com/blogs/big-data/bringing-machine-learning-to-more-builders-through-databases-and-analytics-services/

Machine learning (ML) is becoming more mainstream, but even with the increasing adoption, it’s still in its infancy. For ML to have the broad impact that we think it can have, it has to get easier to do and easier to apply. We launched Amazon SageMaker in 2017 to remove the challenges from each stage of the ML process, making it radically easier and faster for everyday developers and data scientists to build, train, and deploy ML models. SageMaker has made ML model building and scaling more accessible to more people, but there’s a large group of database developers, data analysts, and business analysts who work with databases and data lakes where much of the data used for ML resides. These users still find it too difficult and involved to extract meaningful insights from that data using ML.

This group is typically proficient in SQL but not Python, and must rely on data scientists to build the models needed to add intelligence to applications or derive predictive insights from data. And even when you have the model in hand, there’s a long and involved process to prepare and move data to use the model. The result is that ML isn’t being used as much as it can be.

To meet the needs of this large and growing group of builders, we’re integrating ML into AWS databases, analytics, and business intelligence (BI) services.

AWS customers generate, process, and collect more data than ever to better understand their business landscape, market, and customers. And you don’t just use one type of data store for all your needs. You typically use several types of databases, data warehouses, and data lakes, to fit your use case. Because all these use cases could benefit from ML, we’re adding ML capabilities to our purpose-built databases and analytics services so that database developers, data analysts, and business analysts can train models on their data or add inference results right from their database, without having to export and process their data or write large amounts of ETL code.

Machine Learning for database developers

At re:Invent last year, we announced ML integrated inside Amazon Aurora for developers working with relational databases. Previously, adding ML using data from Aurora to an application was a very complicated process. First, a data scientist had to build and train a model, then write the code to read data from the database. Next, you had to prepare the data so it can be used by the ML model. Then, you called an ML service to run the model, reformat the output for your application, and finally load it into the application.

Now, with a simple SQL query in Aurora, you can add ML to an enterprise application. When you run an ML query in Aurora using SQL, it can directly access a wide variety of ML models from Amazon SageMaker and Amazon Comprehend. The integration between Aurora and each AWS ML service is optimized, delivering up to 100 times better throughput when compared to moving data between Aurora and SageMaker or Amazon Comprehend without this integration. Because the ML model is deployed separately from the database and the application, each can scale up or scale out independently of the other.

In addition to making ML available in relational databases, combining ML with certain types of non-relational database models can also lead to better predictions. For example, database developers use Amazon Neptune, a purpose-built, high-performance graph database, to store complex relationships between data in a graph data model. You can query these graphs for insights and patterns and apply the results to implement capabilities such as product recommendations or fraud detection.

However, human intuition and analyzing individual queries is not enough to discover the full breadth of insights available from large graphs. ML can help, but as was the case with relational databases it requires you to do a significant amount of heavy lifting upfront to prepare the graph data and then select the best ML model to run against that data. The entire process can take weeks.

To help with this, today we announced the general availability of Amazon Neptune ML to provide database developers access to ML purpose-built for graph data. This integration is powered by SageMaker and uses the Deep Graph Library (DGL), a framework for applying deep learning to graph data. It does the hard work of selecting the graph data needed for ML training, automatically choosing the best model for the selected data, exposing ML capabilities via simple graph queries, and providing templates to allow you to customize ML models for advanced scenarios. The following diagram illustrates this workflow.

And because the DGL is purpose-built to run deep learning on graph data, you can improve accuracy of most predictions by over 50% compared to that of traditional ML techniques.

Machine Learning for data analysts

At re:Invent last year, we announced ML integrated inside Amazon Athena for data analysts. With this integration, you can access more than a dozen built-in ML models or use your own models in SageMaker directly from ad-hoc queries in Athena. As a result, you can easily run ad-hoc queries in Athena that use ML to forecast sales, detect suspicious logins, or sort users into customer cohorts.

Similarly, data analysts also want to apply ML to the data in their Amazon Redshift data warehouse. Tens of thousands of customers use Amazon Redshift to process exabytes of data per day. These Amazon Redshift users want to run ML on their data in Amazon Redshift without having to write a single line of Python. Today we announced the preview of Amazon Redshift ML to do just that.

Amazon Redshift now enables you to run ML algorithms on Amazon Redshift data without manually selecting, building, or training an ML model. Amazon Redshift ML works with Amazon SageMaker Autopilot, a service that automatically trains and tunes the best ML models for classification or regression based on your data while allowing full control and visibility.

When you run an ML query in Amazon Redshift, the selected data is securely exported from Amazon Redshift to Amazon Simple Storage Service (Amazon S3). SageMaker Autopilot then performs data cleaning and preprocessing of the training data, automatically creates a model, and applies the best model. All the interactions between Amazon Redshift, Amazon S3, and SageMaker are abstracted away and automatically occur. When the model is trained, it becomes available as a SQL function for you to use. The following diagram illustrates this workflow.

Rackspace Technology – a leading end-to-end multicloud technology services company, and Slalom –  a modern consulting firm focused on strategy, technology, and business transformation are both users of Redshift ML in preview.

Nihar Gupta, General Manager for Data Solutions at Rackspace Technology says “At Rackspace Technology, we help companies elevate their AI/ML operationsthe seamless integration with Amazon SageMaker will empower data analysts to use data in new ways, and provide even more insight back to the wider organization.”

And Marcus Bearden, Practice Director at Slalom shared “We hear from our customers that they want to have the skills and tools to get more insight from their data, and Amazon Redshift is a popular cloud data warehouse that many of our customers depend on to power their analytics, the new Amazon Redshift ML feature will make it easier for SQL users to get new types of insight from their data with machine learning, without learning new skills.”

Machine Learning for business analysts

To bring ML to business analysts, we launched new ML capabilities in Amazon QuickSight earlier this year called ML Insights. ML Insights uses SageMaker Autopilot to enable business analysts to perform ML inference on their data and visualize it in BI dashboards with just a few clicks. You can get results for different use cases that require ML, such as anomaly detection to uncover hidden insights by continuously analyzing billions of data points, to do forecasting, to predict growth, and other business trends. In addition, QuickSight can also give you an automatically generated summary in plain language (a capability we call auto-narratives), which interprets and describes what the data in your dashboard means. See the following screenshot for an example.

Customers like Expedia Group, Tata Consultancy Services, and Ricoh Company are already benefiting from ML out of the box with QuickSight. These human-readable narratives enable you to quickly interpret the data in a shared dashboard and focus on the insights that matter most.

In addition, customers have also been interested in asking questions of their business data in plain language and receiving answers in near-real time. Although some BI tools and vendors have attempted to solve this challenge with Natural Language Query (NLQ), the existing approaches require that you first spend months in advance preparing and building a model on a pre-defined set of data, and even then, you still have no way of asking ad hoc questions when those questions require a new calculation that wasn’t pre-defined in the data model. For example, the question “What is our year-over-year growth rate?” requires that “growth rate” be pre-defined as a calculation in the model. With today’s BI tools, you need to work with your BI teams to create and update the model to account for any new calculation or data, which can take days or weeks of effort.

Last week, we announced Amazon QuickSight Q. ‘Q’ gives business analysts the ability to ask any question of all their data and receive an accurate answer in seconds. To ask a question, you simply type it into the QuickSight Q search bar using natural language and business terminology that you’re familiar with. Q uses ML (natural language processing, schema understanding, and semantic parsing for SQL code generation) to automatically generate a data model that understands the meaning of and relationships between business data, so you can get answers to your business questions without waiting weeks for a data model to be built. Because Q eliminates the need to build a data model, you’re also not limited to asking only a specific set of questions. See the following screenshot for an example.

Best Western Hotels & Resorts is a privately-held hotel brand with a global network of approximately 4,700 hotels in over 100 countries and territories worldwide. “With Amazon QuickSight Q, we look forward to enabling our business partners to self-serve their ad hoc questions while reducing the operational overhead on our team for ad hoc requests,” said Joseph Landucci, Senior Manager of Database and Enterprise Analytics at Best Western Hotels & Resorts. “This will allow our partners to get answers to their critical business questions quickly by simply typing and searching their questions in plain language.”

Summary

For ML to have a broad impact, we believe it has to get easier to do and easier to apply. Database developers, data analysts, and business analysts who work with databases and data lakes have found it too difficult and involved to extract meaningful insights from their data using ML. To meet the needs of this large and growing group of builders, we’ve added ML capabilities to our purpose-built databases and analytics services so that database developers, data analysts, and business analysts can all use ML more easily without the need to be an ML expert. These capabilities put ML in the hands of every data professional so that they can get the most value from their data.


About the Authors

Swami Sivasubramanian is Vice President at AWS in charge of all Amazon AI and Machine Learning services. His team’s mission is “to put machine learning capabilities in the hands on every developer and data scientist.” Swami and the AWS AI and ML organization work on all aspects of machine learning, from ML frameworks (Tensorflow, Apache MXNet and PyTorch) and infrastructure, to Amazon SageMaker (an end-to-end service for building, training and deploying ML models in the cloud and at the edge), and finally AI services (Transcribe, Translate, Personalize, Forecast, Rekognition, Textract, Lex, Comprehend, Kendra, etc.) that make it easier for app developers to incorporate ML into their apps with no ML experience required.

Previously, Swami managed AWS’s NoSQL and big data services. He managed the engineering, product management, and operations for AWS database services that are the foundational building blocks for AWS: DynamoDB, Amazon ElastiCache (in-memory engines), Amazon QuickSight, and a few other big data services in the works. Swami has been awarded more than 250 patents, authored 40 referred scientific papers and journals, and participates in several academic circles and conferences.

 

Herain Oberoi leads Product Marketing for AWS’s Databases, Analytics, BI, and Blockchain services. His team is responsible for helping customers learn about, adopt, and successfully use AWS services. Prior to AWS, he held various product management and marketing leadership roles at Microsoft and a successful startup that was later acquired by BEA Systems. When he’s not working, he enjoys spending time with his family, gardening, and exercising.

 

 

 

Preview: Amazon Lookout for Metrics, an Anomaly Detection Service for Monitoring the Health of Your Business

Post Syndicated from Alex Casalboni original https://aws.amazon.com/blogs/aws/preview-amazon-lookout-for-metrics-anomaly-detection-service-monitoring-health-business/

We are excited to announce Amazon Lookout for Metrics, a new service that uses machine learning (ML) to detect anomalies in your metrics, helping you proactively monitor the health of your business, diagnose issues, and find opportunities quickly – with no ML experience required.

Lookout for Metrics uses the same technology used by Amazon to detect anomalous changes in data that are otherwise hard to find, while reducing the number of false detections. It also groups similar findings together, ranks them by severity, and provides information to determine the root cause of the anomalies.

It can be used across a wide variety of metrics such as revenue, web page views, daily active users, churn rate, transaction volume, mobile app installations, and more. Lookout for Metrics is now available in preview today.

Why Use Amazon Lookout for Metrics for Anomaly Detection?
Organizations across all industries are looking to improve efficiency in their business through technology and automation. While challenges may vary, what’s common is that being able to identify defects and opportunities early and often can lead to material cost savings, higher margins, and better customer experience. Traditionally, organizations rely on manual audits of large amounts of data, which is not scalable and is prone to human error. Others use rule-based methods based on arbitrary ranges, which are often static, do not easily adapt to seasonality changes, and lead to too many false detections.

When anomalies are detected, developers, analysts, and business owners can spend weeks trying to identify the root cause of the change. These are situations where ML can be an effective and transformational tool. However, ML algorithms need to be carefully selected, trained, tested, and deployed for each type of data – requiring a skilled team of ML experts.

Amazon has a long history of being a data-driven company, with a growing number of businesses that need to stay on top of the health of their business, operations, and customer experience. A key part of this effort over the years has involved building and improving ML technology to detect anomalies in key performance indicators (KPI) such as website visits from different traffic channels, number of products added to the shopping cart, number of orders placed, revenue for every product category, and more.

Amazon Lookout for Metrics puts the same ML technology used by Amazon in the hands of every developer. It finds anomalies in your data, groups them intelligently, helps you visualize aggregated results, and automates alerts.

Because it’s a fully managed service, it takes care of the whole ML process so you can get started quickly and focus on your core business. And most importantly, the service improves model performance continually by incorporating your real-time feedback on the accuracy and relevance of the anomalies and root cause analysis.

How Amazon Lookout for Metrics Works
You can get started with Lookout for Metrics with just a few clicks in the AWS Management Console. Without having to write any code, you connect your data to the service through the built-in data source integrations; next Lookout for Metrics trains a custom model for your data; and finally, it begins detecting anomalies for you to review and start taking action on.

Lookout for Metrics continuously monitors data stored in Amazon Simple Storage Service (S3), Amazon Relational Database Service (RDS), Amazon Redshift, Amazon CloudWatch, or SaaS integrations supported by Amazon AppFlow such as Salesforce, Marketo, Google Analytics, Slack, Zendesk, and many more.

During this phase, you can flag each field in your dataset as a measure (or KPI), dimension, or timestamp. For example, if you want to monitor abnormal changes in page views for every device type separately, then you would select page_views as the measure and device_type as the dimension.

Once your data source is configured and connected, Lookout for Metrics inspects and prepares the data for analysis and selects the right algorithm to build the most accurate anomaly detection model. This detector runs on your data at a configurable cadence (every few minutes, hourly, daily, and so on) and provides a threshold dial that allows you to adjust its sensitivity.

When detecting an anomaly, Lookout for Metrics helps you focus on what matters the most by assigning a severity score to aid prioritization. To help you find the root cause, it intelligently groups anomalies that may be related to the same incident and summarizes the different sources of impact (as shown below).

Moreover, you can configure an automatic action such as sending a notification via Amazon Simple Notification Service (SNS), Datadog, PagerDuty, Webhooks, or Slack. Or you can trigger a Lambda function, for example to temporarily hide a product on your e-commerce site when a potential pricing error is detected.

Domain knowledge and expertise can often play an important role in determining if a sudden change in a metric is expected or is an anomaly. Lookout for Metrics allows you to provide real-time feedback on the relevance of the detected anomalies, enabling a powerful human-in-the-loop mechanism. This information is fed back to the anomaly detection model to improve its accuracy.

Who’s Using Amazon Lookout for Metrics Today?
Digitata Networks offers intelligent customer, network and site-centric solutions that assist Mobile Network Operators to monitor, audit, control and automate different aspects of their network. Company CTO Nico Kruger has been pleased with the results he’s seen so far from using Lookout for Metrics.

“We discovered the improved accuracy and insights that Lookout for Metrics can bring to our existing solution and we are thrilled to use the service…we can quickly identify opportunities in addition to finding issues,” he said.

Playrix, one of the leading mobile game developers in the world, known for high-quality games such as Township, Fishdom, and Gardenscapes, is another customer that’s been working with the new service. “We experimented with our user acquisition data to understand how the service works and it quickly identified and grouped anomalies enabling us to work faster and better,” said Mikhail Artyugin, Playrix technical director.

“Lookout for Metrics has saved our team many hours of manual investigation and now notifications are viewed as actionable rather than noise, allowing our teams to easily focus on strategic priorities with less technical overhead,” he added.

“Working with almost a billion impressions every day to capture insights and intent for our customers, we need quick feedback on real data anomalies,” said Brian Ecker, a senior staff engineer at NextRoll, a marketing and data technology company with the mission to provide innovative solutions to companies to keep them growing.

“After working with the Lookout for Metrics team, we saw the improved accuracy that the new service can bring to our existing anomaly detection process and we are thrilled to start using it.”

It’s also worth noting that APN partners such as TensorIoT, Quantiphi, and Provectus have expertise in Lookout for Metrics and can help customers leverage its functionalities.

Available in Preview
Amazon Lookout for Metrics is now available in preview in US East (N. Virginia), US East (Ohio), US West (Oregon), Asia Pacific (Tokyo), and Europe (Ireland).

You can interact with the service using the AWS Management Console, the AWS SDKs and the CLI . Find out more on the technical documentation and get started quickly by joining the preview at the following link.

Request preview access to Amazon Lookout for Metrics here.

Alex

Amazon SageMaker Edge Manager Simplifies Operating Machine Learning Models on Edge Devices

Post Syndicated from Julien Simon original https://aws.amazon.com/blogs/aws/amazon-sagemaker-edge-manager-simplifies-operating-machine-learning-models-on-edge-devices/

Today, I’m extremely happy to announce Amazon SageMaker Edge Manager, a new capability of Amazon SageMaker that makes it easier to optimize, secure, monitor, and maintain machine learning models on a fleet of edge devices.

Edge computing is certainly one of the most exciting developments in information technology. Indeed, thanks to continued advances in compute, storage, networking, and battery technology, organizations routinely deploy large numbers of embedded devices anywhere on the planet for a wide range of industry applications: manufacturing, energy, agriculture, healthcare, and more. Ranging from simple sensors to large industrial machines, the devices have a common purpose: capture data, analyze it, and act on it, for example send an alert if an unwanted condition is detected.

As machine learning (ML) demonstrated its ability to solve a wide range of business problems, customers tried to apply it to edge applications, training models in the cloud and deploying them at the edge in an effort to extract deeper insights from local data. However, given the remote and constrained nature of edge devices, deploying and managing models at the edge is often quite difficult.

For example, a complex model can be too large to fit, forcing customers to settle for a smaller and less accurate model. Also, predicting with several models on the same device (say, to detect different types of anomalies) may require additional code to load and unload models on demand, in order to conserve hardware resources. Finally, monitoring prediction quality is a major concern, as the real world will always be more complex and unpredictable than any training set can anticipate.

Customers asked us to help them solve these challenges, and we got to work.

Announcing Amazon SageMaker Edge Manager
Amazon SageMaker Edge Manager makes it easy for ML edge developers to use the same familiar tools in the cloud or on edge devices. It reduces the time and effort required to get models to production, while continuously monitoring and improving model quality across your device fleet.

Starting from a model that you trained or imported in Amazon SageMaker, SageMaker Edge Manager first optimizes it for your hardware platform using Amazon SageMaker Neo. Launched two years ago, Neo converts models into an efficient common format which is executed on the device by a low footprint runtime. Neo currently supports devices based on chips manufactured by Ambarella, ARM, Intel, NVIDIA, NXP, Qualcomm, TI, and Xilinx.

Then, SageMaker Edge Manager packages the model, and stores it in Amazon Simple Storage Service (S3), where it can be deployed to your devices. In fact, you can deploy multiple models, loading and predicting with a runtime optimized for your hardware of choice.

On-device models are managed by the SageMaker Edge Manager Manager Agent, which communicates with the AWS Cloud for model deployment, and with your application for model management. Indeed, you can integrate this agent with your application, so that it may automatically load and unload models according to your prediction requests. This enables a variety of scenarios, such as freeing all resources for a large model whenever needed, or working with a collection of smaller models that cohabit in memory.

Lenovo, the #1 global PC maker, recently incorporated Amazon SageMaker into its latest predictive maintenance offering. Igor Bergman, Lenovo Vice President, Cloud & Software of PCs and Smart Devices, told us: “At Lenovo, we’re more than a hardware provider and are committed to being a trusted partner in transforming customers’ device experience and delivering on their business goals. Lenovo Device Intelligence is a great example of how we’re doing this with the power of machine learning, enhanced by Amazon SageMaker. With Lenovo Device Intelligence, IT administrators can proactively diagnose PC issues and help predict potential system failures before they occur, helping to decrease downtime and increase employee productivity. By incorporating Amazon SageMaker Neo, we’ve already seen a substantial improvement in the execution of our on-device predictive models – an encouraging sign for the new Amazon SageMaker Edge Manager that will be added in the coming weeks. SageMaker Edge Manager will help eliminate the manual effort required to optimize, monitor, and continuously improve the models after deployment. With it, we expect our models will run faster and consume less memory than with other comparable machine learning platforms. As we extend AI to new applications across the Lenovo services portfolio, we will continue to require a high-performance pipeline that is flexible and scalable both in the cloud and on millions of edge devices. That’s why we selected the Amazon SageMaker platform. With its rich edge-to-cloud and CI/CD workflow capabilities, we can effectively bring our machine learning models to any device workflow for much higher productivity.

Getting Started
As you can see, SageMaker Edge Manager makes it easier to work with ML models deployed on edge devices. It’s available today in the US East (N. Virginia), US West (Oregon), US East (Ohio), Europe (Ireland), Europe (Frankfurt), and Asia Pacific (Tokyo) regions.

Sample notebooks are available to get you started right away. Give them a try, and let us know what you think.

We’re always looking forward to your feedback, either through your usual AWS support contacts, or on the AWS Forum for SageMaker.

– Julien

New – Amazon SageMaker Clarify Detects Bias and Increases the Transparency of Machine Learning Models

Post Syndicated from Julien Simon original https://aws.amazon.com/blogs/aws/new-amazon-sagemaker-clarify-detects-bias-and-increases-the-transparency-of-machine-learning-models/

Today, I’m extremely happy to announce Amazon SageMaker Clarify, a new capability of Amazon SageMaker that helps customers detect bias in machine learning (ML) models, and increase transparency by helping explain model behavior to stakeholders and customers.

As ML models are built by training algorithms that learn statistical patterns present in datasets, several questions immediately come to mind. First, can we ever hope to explain why our ML model comes up with a particular prediction? Second, what if our dataset doesn’t faithfully describe the real-life problem we were trying to model? Could we even detect such issues? Would they introduce some sort of bias in imperceptible ways? As we will see, these are not speculative questions at all. They are very real, and their implications can be far-reaching.

Let’s start with the bias problem. Imagine that you’re working on a model detecting fraudulent credit card transactions. Fortunately, the huge majority of transactions are legitimate, and they make up 99.9% of your dataset, meaning that you only have 0.1% fraudulent transactions, say 100 out of 100,000. Training a binary classification model (legitimate vs. fraudulent), there’s a strong chance that it would be strongly influenced or biased by the majority group. In fact, a trivial model could simply decide that transactions are always legitimate: as useless as this model would be, it would still be right 99.9% of the time! This simple example shows how careful we have to be about the statistical properties of our data, and about the metrics that we use to measure model accuracy.

There are many variants of this under-representation problem. As the number of classes, features, and unique feature values increase, your dataset may only contain a tiny number of training instances for certain groups. In fact, some of these groups may correspond to various socially sensitive features such as gender, age range, or nationality. Under-representation for such groups could result in a disproportionate impact on their predicted outcomes.

Unfortunately, even with the best of intentions, bias issues may exist in datasets and be introduced into models with business, ethical, and regulatory consequences. It is thus important for model administrators to be aware of potential sources of bias in production systems.

Now, let’s discuss the explainability problem. For simple and well-understood algorithms like linear regression or tree-based algorithms, it’s reasonably easy to crack the model open, inspect the parameters that it learned during training, and figure out which features it predominantly uses. You can then decide whether this process is consistent with your business practices, basically saying: “yes, this is how a human expert would have done it.”

However, as models become more and more complex (I’m staring at you, deep learning), this kind of analysis becomes impossible. Just like the prehistoric tribes in Stanley Kubrick’s “2001: A Space Odyssey,” we’re often left staring at an impenetrable monolith and wondering what it all means. Many companies and organizations may need ML models to be explainable before they can be used in production. In addition, some regulations may require explainability when ML models are used as part of consequential decision making, and closing the loop, explainability can also help detect bias.

Thus, our customers asked us for help on detecting bias in their datasets and their models, and on understanding how their models make predictions. We got to work, and came up with SageMaker Clarify.

Introducing Amazon SageMaker Clarify
SageMaker Clarify is a new set of capabilities for Amazon SageMaker, our fully managed ML service. It’s integrated with SageMaker Studio, our web-based integrated development environment for ML, as well as with other SageMaker capabilities like Amazon SageMaker Data Wrangler, Amazon SageMaker Experiments, and Amazon SageMaker Model Monitor.

Thanks to SageMaker Clarify, data scientists are able to:

  • Detect bias in datasets prior to training, and in models after training.
  • Measure bias using a variety of statistical metrics.
  • Explain how feature values contribute to the predicted outcome, both for the model overall and for individual predictions.
  • Detect bias drift and feature importance drift over time, thanks to the integration with Amazon SageMaker Model Monitor.

Let’s look at each of these capabilities.

Detecting dataset bias: This is an important first step. Indeed, a heavily biased dataset may well be unsuitable for training. Knowing this early on certainly saves you time, money, and frustration! Looking at bias metrics computed by SageMaker Clarify on your dataset, you can then add your own bias reduction techniques to your data processing pipeline. Once the dataset has been revised and processed, you can measure bias again, and check if it has actually decreased.

Detecting model bias: After you’ve trained your model, you can run a SageMaker Clarify bias analysis, which includes automatic deployment to a temporary endpoint, and computation of bias metrics using your model and dataset. By computing these metrics, you can figure out if your trained model has similar predictive behavior across groups.

Measuring bias: SageMaker Clarify lets you pick from many different bias metrics. I’ll just give you a few examples here.

  • Difference in positive proportions in labels (DPL): Are labels in the dataset correlated or not with specific sensitive feature values? For example, do people living in a certain city have a better chance of getting a positive answer?
  • Difference in positive proportions in predicted labels (DPPL): Do we overpredict positive labels for a certain group?
  • Accuracy difference (AD): Are the predictions by the model more accurate for one group than the other?
  • Counterfactuals – Fliptest (FT): Suppose we look at each member of one group, and compare with similar members from the other group. Do they get different model predictions?

Explaining predictions – to explain how your model predicts, SageMaker Clarify supports a popular technique called SHapley Additive exPlanations (SHAP). Originating in game theory, SHAP analyzes for each data instance the individual contribution of feature values to the predicted output, and represents them as a positive or negative value. For example, predicting with a credit application model, you could see that Alice’s application is approved with a score of 87.5%, that her employment status (+27.2%) and her credit score (+32.4%) are the strongest contributors to this score, and that her income level has a slight negative impact (-5%). Such insights are crucial in building trust that the model is working as expected, and in explaining to customers and regulators why it comes up with a particular prediction. Further analysis of the SHAP values for your complete dataset can also help identify the relative importance of features and feature values, potentially leading to the discovery of prediction issues and biases.

As you can see, SageMaker Clarify has some pretty powerful features for bias detection and explainability. Fortunately, it also makes them very easy to use. First, you should upload a clean and pre-processed copy of your tabular dataset (CSV or JSON) to Amazon Simple Storage Service (S3). Then, using a built-in container, you just launch an Amazon SageMaker Processing job on your dataset, passing a short configuration file defining the name of the target attribute, the name and values of the sensitive columns to analyze for bias, and the bias metrics that you want to compute. As you would expect, this job runs on fully managed infrastructure. For post-training analysis, a temporary endpoint is also automatically created and deleted by the job. Once the job is complete, results are available in S3 and in SageMaker Studio, and include an auto-generated report that summarizes the results.

Now, I’d like to show you how to get started with SageMaker Clarify.

Exploring Datasets and Models with Amazon SageMaker Clarify
The German Credit Data dataset contains 1,000 labeled credit applications, which I’ve used to train a binary classification model with XGBoost. Each data instance has 20 features, such as credit purpose, credit amount, housing status, employment history, and more. Categorical features have been encoded with Axx values. For example, here’s how the credit history feature is encoded: A30 means ‘no credits taken’, A31 means ‘all credits at this bank paid back duly’, and so on.

In particular, the dataset includes a feature telling us if a customer is a foreign worker. In fact, a quick look at the dataset hints at a large imbalance in favor of foreign workers. Could bias be hiding there? What about the model? Did XGBoost increase or decrease the bias? Which features contribute most to the predicted output? Let’s find out.

After training the model, my next step is to run a SageMaker Clarify bias analysis job on the dataset, using a built-in container image that will compute bias metrics. The job inputs are the dataset, and a JSON configuration file that defines:

  • The name of the target attribute (Class1Good2Bad), and the value for the positive answer (1).
  • The sensitive features to analyze (called “facets”), and their value. Here, we want to focus on instances where ForeignWorker is set to 0, as they seem to be under-represented in the dataset.
  • The bias metrics that the job should compute. As I already have a model, I pass its name so that post-training metrics can be computed on a temporary endpoint.

Here’s the relevant snippet in the configuration file:

"label": "Class1Good2Bad",
"label_values_or_threshold": [1],
"facet": [
        {
         "name_or_index" : "ForeignWorker",
         "value_or_threshold": [0]
        }
    ],
. . .
"methods": {
    "pre_training_bias": {"methods": "all"}
    "post_training_bias": {"methods": "all"}
},
"predictor": {
        "model_name": "xgboost-german-model",
        "instance_type": "ml.m5.xlarge",
        "initial_instance_count": 1
    }

Then, I configure the job inputs (the dataset and the configuration file) and output (the report), passing all appropriate paths in S3:

config_input = ProcessingInput(
                    input_name="analysis_config",
                    source=analysis_config_s3_path,
                    destination="/opt/ml/processing/input/config")
data_input = ProcessingInput(
                    input_name="dataset",
                    source=train_data_s3_path,
                    destination="/opt/ml/processing/input/data")
result_output = ProcessingOutput(
                    source="/opt/ml/processing/output",
                    destination=analysis_result_s3_path,
                    output_name="analysis_result")

Finally, I run the processing job.

from sagemaker.processing import Processor, ProcessingInput, ProcessingJob, ProcessingOutput
analyzer_image_uri = f'678264136642.dkr.ecr.us-east-2.amazonaws.com/sagemaker-xai-analyzer:latest'
analyzer = Processor(base_job_name='analyzer',
                     image_uri=analyzer_image_uri,
                     role=sagemaker.get_execution_role(),
                     instance_count=1,
                     instance_type='ml.c5.xlarge')
analyzer.run(inputs=[ data_input, config_input], outputs=[result_output])

Once the processing job is complete, I can retrieve the report. Let’s look at bias metrics.

Detecting Bias with Amazon SageMaker Clarify
Here are some of the pre-training bias metrics:

"ForeignWorker": [
    {
     "value_or_threshold": "0",
     "metrics": [
      {
       "name": "CI",
       "description": "Class Imbalance (CI)",
       "value": 0.9225
      },
      {
       "name": "DPL",
       "description": "Difference in Positive Proportions in Labels (DPL)",
       "value": -0.21401904442300435
      },
. . . 

The class imbalance metric confirms our visual impression. The dataset has about 92% more foreign workers than it has domestic workers to assess. Whether this imbalance is responsible or not, we can also see that the difference in positive proportion for domestic workers is quite negative. In other words, there’s a smaller proportion of domestic workers with positive labels. This statistical pattern could be picked up by an ML algorithm, leading to a larger proportion of domestic workers getting negative answers. Figuring out whether this is actually legitimate or not would require further analysis, and in any case, it’s great that SageMaker Clarify warned us about this potential issue.

As I provided a trained model, post-training metrics are also available. Comparing the DPPL and the DPL, I can see that XGBoost has slightly reduced bias on positive proportions (-18.8% vs -21.4%). We also see that DAR is negative, indicating that the model achieves higher precision for domestic workers compared to foreign workers.

"ForeignWorker": [
    {
     "value_or_threshold": "0",
     "metrics": [
      {
       "name": "DPPL",
       "description": "\"Difference in Positive Proportions in Predicted Labels (DPPL)\")",
       "value": -0.18801124208230213
      },
      {
       "name": "DAR",
       "description": "Difference in Acceptance Rates (DAR)",
       "value": -0.050909090909090904
      },
      {
       "name": "DRR",
       "description": "Difference in Rejection Rates (DRR)",
       "value": 0.0365296803652968
      },
. . .

As SageMaker Clarify is integrated with SageMaker Studio, I can visualize bias metrics there. All I have to do is find the processing job in the list of trials, right-click “Open in trial details”, and select the “Bias report” view.

SageMaker screenshot

Finally, deciding whether high value of a certain bias metric is problematic involves domain-specific considerations. This needs to be guided by ethical, social, regulatory, and business considerations. Similarly, interventions for removing bias may often need a careful analysis of the entire ML lifecycle, from problem formulation to feedback loops in deployment.

Now, let’s see how SageMaker Clarify helps us understand what features the models base their predictions on.

Explaining Predictions with Amazon SageMaker Clarify
The report includes global SHAP values, showing the relative importance of all the features in the dataset. On the feature importance graph available in SageMaker Studio, I see that the three most important features are credit duration, not having a checking account (A14), and the loan amount. All things being equal, the bank probably sees you as a safer customer if you’re borrowing a small amount over a short period of time, and without the possibility to write checks!

SageMaker screenshot

In S3, I can also find a CSV file with SHAP values for individual data instances, giving me a complete picture of feature and feature value importance.

Getting Started
As you can see, SageMaker Clarify is a powerful tool to detect bias and to understand how your model works. You can start using it today in all regions where Amazon SageMaker is available, at no additional cost.

Sample notebooks are available to get you started quickly. Give them a try, and let us know what you think. We’re always looking forward to your feedback, either through your usual AWS support contacts, or on the AWS Forum for SageMaker.

– Julien

Special thanks to my colleagues Sanjiv Das, Michele Donini, Jason Gelman, Krishnaram Kenthapadi, Pinar Yilmaz, and Bilal Zafar for their precious help.

Dataset credits: Dua, D. and Graff, C. (2019). UCI Machine Learning Repository. Irvine, CA: University of California, School of Information and Computer Science.

New – Profile Your Machine Learning Training Jobs With Amazon SageMaker Debugger

Post Syndicated from Julien Simon original https://aws.amazon.com/blogs/aws/profile-your-machine-learning-training-jobs-with-amazon-sagemaker-debugger/

Today, I’m extremely happy to announce that Amazon SageMaker Debugger can now profile machine learning models, making it much easier to identify and fix training issues caused by hardware resource usage.

Despite its impressive performance on a wide range of business problems, machine learning (ML) remains a bit of a mysterious topic. Getting things right is an alchemy of science, craftsmanship (some would say wizardry), and sometimes luck. In particular, model training is a complex process whose outcome depends on the quality of your dataset, your algorithm, its parameters, and the infrastructure you’re training on.

As ML models become ever larger and more complex (I’m looking at you, deep learning), one growing issue is the amount of infrastructure required to train them. For instance, training BERT on the publicly available COCO dataset takes well over six hours on a single p3dn.24xlarge instance, even with its eight NVIDIA V100 GPUs. Some customers like autonomous vehicle companies deal with much larger datasets, and train object detection models for several days.

When a complex training job takes this long, the odds that something goes wrong and ruins it are pretty high, not only wasting time and money but also causing lots of frustration. Important work needs to be put on the back burner while you investigate, figure out the root cause, try to fix it, and then run your training job again. Often, you’ll have to iterate quite a few times to nail the problem.

Depending on the ML framework that you use, and sometimes on its version, you may or may not be able to use existing framework-specific tools. Often, you’ll have to build and maintain your own bespoke tools. Even for experienced practitioners, this is a lot of hard work. For regular developers like me, this is an utterly daunting task.

Introducing Model Profiling in Amazon SageMaker Debugger
Launched last year at AWS re:Invent, Amazon SageMaker Debugger is a capability of Amazon SageMaker that automatically identifies complex issues developing in ML training jobs. These include loss not decreasing, exploding gradients, and more.

Now, SageMaker Debugger can also monitor hardware resource usage, and allows you to profile your training job to help you correlate resource usage to ML operations in your training script. Thus, you’ll be able to resolve performance issues much quicker, and iterate through your training job much faster.

Chaim Rand, ML Algorithm Developer at Mobileye, an Intel company building automated driving and driver assistance systems, had the opportunity to work with the new profiling capabilities, and here’s what he told us: “Many of the assisted driving and autonomous vehicle technologies that we develop at Mobileye, rely on training deep neural network models to detect a wide variety of road artifacts, including vehicles, pedestrians, speed bumps, road signs and more. Often, these models train on extremely large datasets, on multiple machines, and for periods of up to several days. For us, at Mobileye, it is imperative that we have a toolkit of advanced performance profiling capabilities, for analyzing the flow of data across the network, CPU, and GPU resources, and for pinpointing performance issues. The profiling functionality in SageMaker Debugger provides just that, taking performance profiling out of the domain of a few specialized experts, and empowering our algorithm developers to maximize training resource utilization, accelerate model convergence, and reduce cost.

At launch, the new profiling capability of SageMaker Debugger is available for TensorFlow 2.x and PyTorch 1.x. All you have to do is to train with the corresponding built-in frameworks in Amazon SageMaker. Distributed training is supported out of the box.

Setting a single parameter in your SageMaker estimator, and without any change to your training code, you can enable the collection of infrastructure and model metrics such as:

  • CPU and GPU,
  • RAM and GPU RAM,
  • Network I/O,
  • Storage I/O (local storage and Pipe Mode),
  • Python metrics,
  • Data loading time,
  • Time spent in ML operators running on CPU and GPU,
  • Distributed training metrics for Horovod,
  • and many more.

In addition, you can visualize how much time is spent in different phases, such as preprocessing, training loop, and postprocessing. If needed, you can drill down on each training epoch, and even on each function in your training script.

By default, metrics are collected every 500ms, and you can also set this value to 100ms, 200ms, 1s, 5s, and 1min. For finer-grained analysis, you can also enable and disable profiling explicitly in your training code, only capturing metrics for specific parts.

While your training job is running, you can easily visualize these metrics in Amazon SageMaker Studio, our web-based integrated development environment for ML. As you would expect, all data is also available through the SageMaker Debugger API, and you can retrieve it to build your own graphs.

Running in parallel of the training job, an Amazon SageMaker Processing analyzes captured data, builds graphs, and generates a report providing insights on potential problems. This doesn’t require any work on your part, as this analysis runs inside a built-in container on fully managed infrastructure.

Now, let’s run a demo with PyTorch, where we’ll profile a ResNet-50 image classification model training on the CIFAR-10 dataset.

Profiling a Training Job with Amazon SageMaker Debugger
All it takes to enable profiling on your training job is an extra parameter in your SageMaker estimator. You don’t need to change a line in your training code. By default, SageMaker Debugger uses a set of built-in profiling rules looking for unwanted conditions that could develop during training, such as low GPU utilization. On top of reporting these conditions, SageMaker Debugger also triggers events in CloudWatch Events. For example, I could use them to run a AWS Lambda function that automatically stops inefficient training jobs.

First, I create a profiling configuration capturing data every 500ms. Optionally, I could select a training step interval if I wanted to profile only a certain portion of the job.

import sagemaker
from sagemaker.profiler import ProfilerConfig 
profiler_config = ProfilerConfig(profiling_interval_millis=500)

Then, I pass this configuration to my PyTorch Estimator, training on an ml.p3.8xlarge instance equipped with 4 NVIDIA V100 GPUs.

from sagemaker.pytorch import PyTorch
estimator = PyTorch(
    role=sagemaker.get_execution_role(),
    instance_count=1,
    instance_type='ml.p3.8xlarge',
    entry_point='train_pt.py',
    framework_version='1.5.0',
    hyperparameters={"batch_size":512, "epochs":10},
    profiler_config=profiler_config)

Then, I launch the training job as usual. Once the job is running, profiling data is captured and stored in S3.

path = estimator.latest_job_profiler_artifacts_path()
print(path)
s3://sagemaker-us-east-2-123456789012/pt-train-pt-2020-11-17-17-38-43-231/profiler-output

Using the SageMaker SDK, I can retrieve and count profiling events.

from smdebug.profiler.system_metrics_reader import S3SystemMetricsReader
system_metrics_reader = S3SystemMetricsReader(path)
system_metrics_reader.refresh_event_file_list()
last_timestamp = system_metrics_reader.get_timestamp_of_latest_available_file()
events = system_metrics_reader.get_events(0, last_timestamp)
print("Found", len(events), "recorded system metric events. Latest recorded event:", last_timestamp)
Found 411853 recorded system metric events. Latest recorded event: 1605620280000000

Of course, I could parse and analyze these profiling events, build my own graphs, and so on. Instead, let’s visualize them in near real-time in SageMaker Studio.

While my training job is still running, I locate it in SageMaker Studio, and I right-click “Open Debugger for insights”.

SageMaker screenshot

This opens a new tab, and I select the “Nodes” panel where I can see details statistics for each instance in my training job. So, how’s my training job doing? Feel free to click on the image below to zoom in.

SageMaker screenshot

Apparently, this job isn’t going great. GPU utilization and GPU memory utilization are desperately flat at around 10%. I’m definitely not pushing my multi-GPU instance hard enough. Maybe GPUs are not receiving data fast enough because the CPU can’t keep up? Let’s check the system utilization heatmap.

SageMaker screenshot

The CPU is taking a nap here, hardly ever exceeding 20% usage. This instance is definitely not busy enough. Is there anything I could do to fix this?

Switching to the “Overview” panel, I see that some of the built-in profiling rules have been triggered.

SageMaker screenshot

LowGPUUtilization confirms what I saw on the graphs above. BatchSize is very interesting, as it suggests increasing the size of mini-batches sent to the GPUs by the training script running on the CPU. This should definitely help fill GPU memory, put more GPU cores to work, speed up my training job, and improve infrastructure usage.

At this point, I should decide to stop my inefficient training job, and to relaunch it with a larger batch size. Here, I’ll let it run to completion to show you the report generated by the SageMaker Processing job running in parallel of your training job.

Once the training job is complete, I can see its summary in the “Overview” panel.

SageMaker screenshot

Clicking on the “Download report” button, I get a very detailed report that includes additional metrics, for example the ratio between the different phases of the training job, or the ratio between the forward and backward pass.

SageMaker screenshot

I can also see information on the most time-consuming CPU and GPU operators, which is really important if I wanted to optimize my code. For example, the graph below tells me that the most time-consuming GPU operations in my training job are backward pass convolution operators.

SageMaker screenshot

There’s much more to read in the report (rules summary, training loop analysis, and more). A companion notebook is also available to understand how graphs have been built, and how you can tailor them to your own needs.

Getting Started
We’ve just scratched the surface, and there are many more features in Amazon SageMaker Debugger that make it easy to gather, analyze and visualize model profiling information. You can start using it today in all regions where Amazon SageMaker is available. You won’t be charged for any compute used to run built-in profiling rules.

You’ll find sample notebooks on Github, so give them a try, and let us know what you think. We’re always looking forward to your feedback, either through your usual AWS support contacts, or on the AWS Forum for SageMaker.

– Julien

New – Managed Data Parallelism in Amazon SageMaker Simplifies Training on Large Datasets

Post Syndicated from Julien Simon original https://aws.amazon.com/blogs/aws/managed-data-parallelism-in-amazon-sagemaker-simplifies-training-on-large-datasets/

Today, I’m particularly happy to announce that Amazon SageMaker now supports a new data parallelism library that makes it easier to train models on datasets that may be as large as hundreds or thousands of gigabytes.

As data sets and models grow larger and more sophisticated, machine learning (ML) practitioners working on large distributed training jobs have to face increasingly long training times, even when using powerful instances such as the Amazon Elastic Compute Cloud (EC2) p3 and p4 instances. For example, using a ml.p3dn.24xlarge instance equipped with 8 NVIDIA V100 GPUs, it takes over 6 hours to train advanced object detection models such as Mask RCNN and Faster RCNN on the publicly available COCO dataset. Likewise, training BERT, a state of the art natural language processing model, takes over 100 hours on the same instance. Some of our customers, such as autonomous vehicle companies, routinely deal with even larger training jobs that run for days on large GPU clusters.

As you can imagine, these long training times are a severe bottleneck for ML projects, hurting productivity and slowing down innovation. Customers asked us for help, and we got to work.

Introducing Data Parallelism in Amazon SageMaker
Amazon SageMaker now helps ML teams reduce distributed training time and cost, thanks to the SageMaker Data Parallelism (SDP) library. Available for TensorFlow and PyTorch, SDP implements a more efficient distribution of computation, optimizes network communication, and fully utilizes our fastest p3 and p4 GPU instances.

Up to 90% of GPU resources can now be used for training, not for data transfer. Distributed training jobs can achieve up near-liner scaling efficiency, regardless of the number of GPUs involved. In other words, if a training job runs for 8 hours on a single instance, it will only take approximately 1 hour on 8 instances, with minimal cost increase. SageMaker effectively eliminates any trade-off between training cost and training time, allowing ML teams to get results sooner, iterate faster, and accelerate innovation.

During his keynote at AWS re:Invent 2020, Swami Sivasubramanian demonstrated the fastest training times to date for T5-3B and Mask-RCNN.

  • The T5-3B model has 3 billion parameters, achieves state-of-the-art accuracy on natural language processing benchmarks, and usually takes weeks of effort to train and tune for performance. We trained this model in 6 days on 256 ml.p4d.24xlarge instances.
  • Mask-RCNN continues to be a popular instance segmentation model used by our customers. Last year at re:Invent, we trained Mask-RCNN in 26 minutes on PyTorch, and in 27 minutes on TensorFlow. This year, we recorded the fastest training time to date for Mask-RCNN at 6:12 minutes on TensorFlow, and 6:45 minutes on PyTorch.

Before we explain how Amazon SageMaker is able to achieve such speedups, let’s first explain how data parallelism works, and why it’s hard to scale.

A Primer on Data Parallelism
If you’re training a model on a single GPU, its full internal state is available locally: model parameters, optimizer parameters, gradients (parameter updates computed by backpropagation), and so on. However, things are different when you distribute a training job to a cluster of GPUs.

Using a technique named “data parallelism,” the training set is split in mini-batches that are evenly distributed across GPUs. Thus, each GPU only trains the model on a fraction of the total data set. Obviously, this means that the model state will be slightly different on each GPU, as they will process different batches. In order to ensure training convergence, the model state needs to be regularly updated on all nodes. This can be done synchronously or asynchronously:

  • Synchronous training: all GPUs report their gradient updates either to all other GPUs (many-to-many communication), or to a central parameter server that redistributes them (many-to-one, followed by one-to-many). As all updates are applied simultaneously, the model state is in sync on all GPUs, and the next mini-batch can be processed.
  • Asynchronous training: gradient updates are sent to all other nodes, or to a central server. However, they are applied immediately, meaning that model state will differ from one GPU to the next.

Unfortunately, these techniques don’t scale very well. As the number of GPUs increases, a parameter server will inevitably become a bottleneck. Even without a parameter server, network congestion soon becomes a problem, as n GPUs need to exchange n*(n-1) messages after each iteration, for a total amount of n*(n-1)*model size bytes. For example, ResNet-50 is a popular model used in computer vision applications. With its 26 million parameters, each 32-bit gradient update takes about 100 megabytes. With 8 GPUs, each iteration requires sending and receiving 56 updates, for a total of 5.6 gigabytes. Even with a fast network, this will cause some overhead, and slow down training.

A significant step forward was taken in 2017 thanks to the Horovod project. Horovod implemented an optimized communication algorithm for distributed training named “ring-allreduce,” which was soon integrated with popular deep learning libraries.

In a nutshell, ring-allreduce is a decentralized asynchronous algorithm. There is no parameter server: nodes are organized in a directed cycle graph (to put it simply, a one-way ring). For each iteration, a node receives a gradient update from its predecessor. Once a node has processed its own batch, it applies both updates (its own and the one it received), and sends the results to its neighbor. With n GPUs, each GPU processes 2*(n-1) messages before all GPUs have been updated. Accordingly, the total amount of data exchanged per GPU is 2*(n-1)*model size, which is much better than n*(n-1)*model size.

Still, as datasets keep growing, the network bottleneck issue often rises again. Enter SageMaker and its new AllReduce algorithm.

A New Data Parallelism Algorithm in Amazon SageMaker
With the AllReduce algorithm, GPUs don’t talk to one another any more. Each GPU stores its gradient updates in GPU memory. When a certain threshold is exceeded, these updates are sharded, and sent to parameter servers running on the CPUs of the GPU instances. This removes the need for dedicated parameter servers.

Each CPU is responsible for a subset of the model parameters, and it receives updates coming from all GPUs. For example, with 3 training instances equipped with a single GPU, each GPU in the training cluster would send a third of its gradient updates to each one of the three CPUs.

Illustration

Then, each CPU would apply all the gradient updates that it received, and it would distributes the consolidated result back to all GPUs.

Illustration

Now that we understand how this algorithm works, let’s see how you can use it with your own code, without having to manage any infrastructure.

Training with Data Parallelism in Amazon SageMaker
The SageMaker Data Parallelism API is designed for ease of use, and should provide seamless integration with existing distributed training toolkits. In most cases, all you have to change in your training code is the import statement for Horovod (TensorFlow), or for Distributed Data Parallel (PyTorch).

For PyTorch, this would look like this.

import smdistributed.dataparallel.torch.parallel.distributed as dist
dist.init_process_group()

Then, I need to pin each GPU to a single SDP process.

torch.cuda.set_device(dist.get_local_rank())

Then, I define my model as usual, for example:

class Net(nn.Module):
    def __init__(self):
        super(Net, self).__init__()
        self.conv1 = nn.Conv2d(1, 32, 3, 1)
        self.conv2 = nn.Conv2d(32, 64, 3, 1)
        self.dropout1 = nn.Dropout2d(0.25)
        self.dropout2 = nn.Dropout2d(0.5)
        self.fc1 = nn.Linear(9216, 128)
        self.fc2 = nn.Linear(128, 10)
...

Finally, I instantiate my model, and use it to create a DistributedDataParallel object like so:

import torch
from smdistributed.dataparallel.torch.parallel.distributed import DistributedDataParallel as DDP
device = torch.device("cuda")
model = DDP(Net().to(device))

The rest of the code is vanilla PyTorch, and I can train it using the PyTorch estimator available in the SageMaker SDK. Here, I’m using an ml.p3.16xlarge instance with 8 NVIDIA V100 GPUs.

from sagemaker.pytorch import PyTorch
estimator = PyTorch(
    entry_point='train_pytorch.py',
    role=sagemaker.get_execution_role(),
    framework_version='1.6.0',
    instance_count=1,
    instance_type='ml.p3.16xlarge',
    distribution={'smdistributed':{'dataparallel':{enabled': True}}}
)
estimator.fit()

From then on, SageMaker takes over and provisions all required infrastructure. You can focus on other tasks while your training job runs.

Getting Started
If your training jobs last for hours or days on multiple GPUs, we believe that the SageMaker Data Parallelism library can save you time and money, and help you experiment and innovate quicker. It’s available today at in all regions where SageMaker is available, at no additional cost.

Examples are available to get you started quickly. Give them a try, and let us know what you think. We’re always looking forward to your feedback, either through your usual AWS support contacts, or on the AWS Forum for SageMaker.

– Julien

Amazon SageMaker Simplifies Training Deep Learning Models With Billions of Parameters

Post Syndicated from Julien Simon original https://aws.amazon.com/blogs/aws/amazon-sagemaker-simplifies-training-deep-learning-models-with-billions-of-parameters/

Today, I’m extremely happy to announce that Amazon SageMaker simplifies the training of very large deep learning models that were previously difficult to train due to hardware limitations.

In the last 10 years, a subset of machine learning named deep learning (DL) has taken the world by storm. Based on neural networks, DL algorithms have an extraordinary ability to extract information patterns hidden in vast amounts of unstructured data, such as images, videos, speech, or text. Indeed, DL has quickly achieved impressive results on a variety of complex human-like tasks, especially on computer vision and natural language processing. In fact, innovation has never been faster, as DL keeps improving its results on reference tasks like the ImageNet Large Scale Visual Recognition Challenge (ILSVRC), the General Language Understanding Evaluation (GLUE), or the Stanford Question Answering Dataset (SQUAD).

In order to tackle ever more complex tasks, DL researchers are designing increasingly sophisticated models, adding more neuron layers and more connections to improve pattern extraction and prediction accuracy, with a direct impact on model size. For example, you would get very good results on image classification with a 100-megabyte ResNet-50 model. For more difficult tasks such as object detection or instance segmentation, you would have to use larger models such as Mask R-CNN or YOLO v4, weighing in at about 250 megabytes.

As you can guess, model growth also impacts the amount of time and hardware resources required for model training, which is why Graphical Processing Units (GPU) have long been the preferred option to train and fine-tune large DL models. Thanks to their massively parallel architecture and their large on-board memory, they make it possible to use a technique called mini-batch training. By sending several data samples at once to the GPU, instead of sending them one by one, communication overhead is reduced, and training jobs are greatly accelerated. For example, the NVIDIA A100 available on the Amazon Elastic Compute Cloud (EC2) p4 family has over 7,000 compute cores and 40 gigabytes of fast onboard memory. Surely, that should be enough to train large batches of data on very large models, shouldn’t it?

Well, it’s not. Natural language processing behemoths such as OpenAI GPT-2 (1.5 billion parameters), T5-3B (3 billion parameters) and GPT-3 (175 billion parameters) consume tens or even hundreds of gigabytes of GPU memory. Likewise, state-of-the-art models working on high-resolution 3D images can be too large to fit in GPU memory, even with a batch size of 1…

Trying to square the circle, DL researchers use a combination of techniques, such as the following:

  • Buy more powerful GPUs, although we just saw that this is simply not an option for some models.
  • Work with less powerful models, and sacrifice accuracy.
  • Implement gradient checkpointing, a technique that relies on saving intermediate training results to disk instead of keeping everything in memory, at the expense of a 20-30% training slowdown.
  • Implement model parallelism, that is to say split the model manually, and train its (smaller) pieces on different GPUs. Needless to say, this is an extremely difficult, time-consuming, and uncertain task, even for expert practitioners.

Customers have told us that none of the above was a satisfactory solution to working with very large models. They asked us for a simpler and more cost-effective solution, and we got to work.

Introducing Model Parallelism in Amazon SageMaker
Model parallelism in SageMaker automatically and efficiently partitions models across several GPUs, eliminating the need for accuracy compromises or for complex manual work. In addition, thanks to this scale-out approach to model training, not only can you work with very large models without any memory bottleneck, you can also leverage a large number of smaller and more cost-effective GPUs.

At launch, this is supported for TensorFlow and PyTorch, and it only requires minimal changes in your code. When you launch a training job, you can specify whether your model should be optimized for speed or for memory usage. Then, Amazon SageMaker runs an initial profiling job on your behalf in order to analyze the compute and memory requirements of your model. This information is then fed to a partitioning algorithm which decides how to split the model and how to map model partitions to GPUs, while minimizing communication. The outcome of the partitioning decision is saved to a file, which is passed as input to the actual training job.

As you can see, SageMaker takes care of everything. If you’d like, you could also manually profile and partition the model, then train on SageMaker.

Before we look at the code, I’d like to give you a quick overview of the internals.

Training with Model Partitions and Microbatches
As model partitions running on different GPUs expect forward pass inputs from each other (activation values), processing training mini-batches across a sequence of partitions would only keep one partition busy at all times, while stalling the other ones.

To avoid this inefficient behavior, mini-batches are split into microbatches that are processed in parallel on the different GPUs. For example, GPU #1 could be forward propagating microbatch n, while GPU #2 could do the same for microbatch n+1. Activation values can be stored, and passed to the next partition whenever it’s ready to accept them.

For back propagation, partitions also expect input values from each other (gradients). As a partition can’t simultaneously run forward and backward propagation, we could wait for all GPUs to complete the forward pass on their own microbatch, before letting them run the corresponding backward pass. This simple mode is available in Amazon SageMaker.

There’s an even more efficient option, called interleaved mode. Here, SageMaker replicates partitions according to the number of microbatches. For example, working with 2 microbatches, each GPU would run two copies of the partition it has received. Each copy would collaborate with partitions running on other GPUs, either for forward or backpropagation.

Here’s how things could look like, with 4 different microbatches being processed by 2 duplicated partitions.

Illustration

To sum things up, interleaving the forward and backward passes of different microbatches is how SageMaker maximimes GPU utilization.

Now, let’s see how we can put this to work with TensorFlow.

Implementing Model Parallelism in Amazon SageMaker
Thanks to the SageMaker Model Parallelism (SMP) library, you can easily implement model parallelism in your own TensorFlow code (the process is similar for PyTorch). Here’s what you need to do:

  • Define and initialize the partitioning configuration.
  • Make your model a subclass of the DistributedModel class, using standard Keras subclassing.
  • Write and decorate with @smp.step a training function that represents a forward and backward step for the model. This function will be pipelined according to the architecture described in the previous section.
  • Optionally, do the same for an evaluation function that will also be pipelined.

Let’s apply this to a simple convolution network training on the MNIST dataset, using an ml.p3.8xlarge instance equipped with 4 NVIDIA V100 GPUs.

First, I initialize the SMP API.

import smdistributed.modelparallel.tensorflow as smp
smp.init()

Then, I subclass DistributedModel and build my model.

class MyModel(smp.DistributedModel):
    def __init__(self):
        super(MyModel, self).__init__()
        self.conv = Conv2D(32, 3, activation="relu")
        self.flatten = Flatten()
        self.dense1 = Dense(128)
        self.dense2 = Dense(10)
. . .

This is what the training function looks like.

@smp.step
def forward_backward(images, labels):
    predictions = model(images, training=True)
    loss = loss_obj(labels, predictions)
    grads = optimizer.get_gradients(loss, model.trainable_variables)
    return grads, loss

Then, I can train as usual with the TensorFlow estimator available in the SageMaker SDK. I only need to add the model parallelism configuration: 2 partitions (hence training on 2 GPUs), and 2 microbatches (hence 2 copies of each partition) with interleaving.

smd_mp_estimator = TensorFlow(
    entry_point="tf2.py",
    role=role,
    framework_version='2.3.1',
    pv_version='py3',
    instance_count=1,
    instance_type='ml.p3.16xlarge',
    distribution={
        "smdistributed": {
            "modelparallel": {
                "enabled":True,
                "parameters": {
                    "microbatches": 2,
                    "partitions": 2,
                    "pipeline": "interleaved",
                    "optimize": "memory",
                    "horovod": True, 
                }
             }
         },
        "mpi": {
            "enabled": True,
            "processes_per_host": 2, # Pick your processes_per_host
            "custom_mpi_options": mpioptions
        },
    }
)

Getting Started
As you can see, model parallelism makes it easier to train very large state-of-the-art deep learning models. It’s available today in all regions where Amazon SageMaker is available, at no additional cost.

Examples are available to get you started right away. Give them a try, and let us know what you think. We’re always looking forward to your feedback, either through your usual AWS support contacts, or on the AWS Forum for SageMaker.

– Julien

 

re:Invent 2020 Liveblog: Machine Learning Keynote

Post Syndicated from AWS News Blog Team original https://aws.amazon.com/blogs/aws/reinvent-2020-liveblog-machine-learning-keynote/

Swami Sivasubramanian speaks on stage at AWS re:InventFollow along as AWS Chief Evangelist Jeff Barr and Developer Advocates Martin Beeby and Steve Roberts liveblog the first-ever Machine Learning Keynote. Swami Sivasubramanian, VP of Amazon ML/AI will share the latest developments and launches in AWS machine learning, as well as demos of new technology, and insights from customers.

Join us here from 7:45-10 AM (PST), Tuesday, Dec. 8, 2020! 

 


Raising code quality for Python applications using Amazon CodeGuru

Post Syndicated from Ran Fu original https://aws.amazon.com/blogs/devops/raising-code-quality-for-python-applications-using-amazon-codeguru/

We are pleased to announce the launch of Python support for Amazon CodeGuru, a service for automated code reviews and application performance recommendations. CodeGuru is powered by program analysis and machine learning, and trained on best practices and hard-learned lessons across millions of code reviews and thousands of applications profiled on open-source projects and internally at Amazon.

Amazon CodeGuru has two services:

  • Amazon CodeGuru Reviewer – Helps you improve source code quality by detecting hard-to-find defects during application development and recommending how to remediate them.
  • Amazon CodeGuru Profiler – Helps you find the most expensive lines of code, helps reduce your infrastructure cost, and fine-tunes your application performance.

The launch of Python support extends CodeGuru beyond its original Java support. Python is a widely used language for various use cases, including web app development and DevOps. Python’s growth in data analysis and machine learning areas is driven by its rich frameworks and libraries. In this post, we discuss how to use CodeGuru Reviewer and Profiler to improve your code quality for Python applications.

CodeGuru Reviewer for Python

CodeGuru Reviewer now allows you to analyze your Python code through pull requests and full repository analysis. For more information, see Automating code reviews and application profiling with Amazon CodeGuru. We analyzed large code corpuses and Python documentation to source hard-to-find coding issues and trained our detectors to provide best practice recommendations. We expect such recommendations to benefit beginners as well as expert Python programmers.

CodeGuru Reviewer generates recommendations in the following categories:

  • AWS SDK APIs best practices
  • Data structures and control flow, including exception handling
  • Resource leaks
  • Secure coding practices to protect from potential shell injections

In the following sections, we provide real-world examples of bugs that can be detected in each of the categories:

AWS SDK API best practices

AWS has hundreds of services and thousands of APIs. Developers can now benefit from CodeGuru Reviewer recommendations related to AWS APIs. AWS recommendations in CodeGuru Reviewer cover a wide range of scenarios such as detecting outdated or deprecated APIs, warning about API misuse, authentication and exception scenarios, and efficient API alternatives.

Consider the pagination trait, implemented by over 1,000 APIs from more than 150 AWS services. The trait is commonly used when the response object is too large to return in a single response. To get the complete set of results, iterated calls to the API are required, until the last page is reached. If developers were not aware of this, they would write the code as the following (this example is patterned after actual code):

def sync_ddb_table(source_ddb, destination_ddb):
    response = source_ddb.scan(TableName=“table1”)
    for item in response['Items']:
        ...
        destination_ddb.put_item(TableName=“table2”, Item=item)
    …   

Here the scan API is used to read items from one Amazon DynamoDB table and the put_item API to save them to another DynamoDB table. The scan API implements the Pagination trait. However, the developer missed iterating on the results beyond the first scan, leading to only partial copying of data.

The following screenshot shows what CodeGuru Reviewer recommends:

The following screenshot shows CodeGuru Reviewer recommends on the need for pagination

The developer fixed the code based on this recommendation and added complete handling of paginated results by checking the LastEvaluatedKey value in the response object of the paginated API scan as follows:

def sync_ddb_table(source_ddb, destination_ddb):
    response = source_ddb.scan(TableName==“table1”)
    for item in response['Items']:
        ...
        destination_ddb.put_item(TableName=“table2”, Item=item)
    # Keeps scanning util LastEvaluatedKey is null
    while "LastEvaluatedKey" in response:
        response = source_ddb.scan(
            TableName="table1",
            ExclusiveStartKey=response["LastEvaluatedKey"]
        )
        for item in response['Items']:
            destination_ddb.put_item(TableName=“table2”, Item=item)
    …   

CodeGuru Reviewer recommendation is rich and offers multiple options for implementing Paginated scan. We can also initialize the ExclusiveStartKey value to None and iteratively update it based on the LastEvaluatedKey value obtained from the scan response object in a loop. This fix below conforms to the usage mentioned in the official documentation.

def sync_ddb_table(source_ddb, destination_ddb):
    table = source_ddb.Table(“table1”)
    scan_kwargs = {
                  …
    }
    done = False
    start_key = None
    while not done:
        if start_key:
            scan_kwargs['ExclusiveStartKey'] = start_key
        response = table.scan(**scan_kwargs)
        for item in response['Items']:
            destination_ddb.put_item(TableName=“table2”, Item=item)
        start_key = response.get('LastEvaluatedKey', None)
        done = start_key is None

Data structures and control flow

Python’s coding style is different from other languages. For code that does not conform to Python idioms, CodeGuru Reviewer provides a variety of suggestions for efficient and correct handling of data structures and control flow in the Python 3 standard library:

  • Using DefaultDict for compact handling of missing dictionary keys over using the setDefault() API or dealing with KeyError exception
  • Using a subprocess module over outdated APIs for subprocess handling
  • Detecting improper exception handling such as catching and passing generic exceptions that can hide latent issues.
  • Detecting simultaneous iteration and modification to loops that might lead to unexpected bugs because the iterator expression is only evaluated one time and does not account for subsequent index changes.

The following code is a specific example that can confuse novice developers.

def list_sns(region, creds, sns_topics=[]):
    sns = boto_session('sns', creds, region)
    response = sns.list_topics()
    for topic_arn in response["Topics"]:
        sns_topics.append(topic_arn["TopicArn"])
    return sns_topics
  
def process():
    ...
    for region, creds in jobs["auth_config"]:
        arns = list_sns(region, creds)
        ... 

The process() method iterates over different AWS Regions and collects Regional ARNs by calling the list_sns() method. The developer might expect that each call to list_sns() with a Region parameter returns only the corresponding Regional ARNs. However, the preceding code actually leaks the ARNs from prior calls to subsequent Regions. This happens due to an idiosyncrasy of Python relating to the use of mutable objects as default argument values. Python default value are created exactly one time, and if that object is mutated, subsequent references to the object refer to the mutated value instead of re-initialization.

The following screenshot shows what CodeGuru Reviewer recommends:

The following screenshot shows CodeGuru Reviewer recommends about initializing a value for mutable objects

The developer accepted the recommendation and issued the below fix.

def list_sns(region, creds, sns_topics=None):
    sns = boto_session('sns', creds, region)
    response = sns.list_topics()
    if sns_topics is None: 
        sns_topics = [] 
    for topic_arn in response["Topics"]:
        sns_topics.append(topic_arn["TopicArn"])
    return sns_topics

Resource leaks

A Pythonic practice for resource handling is using Context Managers. Our analysis shows that resource leaks are rampant in Python code where a developer may open external files or windows and forget to close them eventually. A resource leak can slow down or crash your system. Even if a resource is closed, using Context Managers is Pythonic. For example, CodeGuru Reviewer detects resource leaks in the following code:

def read_lines(file):
    lines = []
    f = open(file, ‘r’)
    for line in f:
        lines.append(line.strip(‘\n’).strip(‘\r\n’))
    return lines

The following screenshot shows that CodeGuru Reviewer recommends that the developer either use the ContextLib with statement or use a try-finally block to explicitly close a resource.

The following screenshot shows CodeGuru Reviewer recommend about fixing the potential resource leak

The developer accepted the recommendation and fixed the code as shown below.

def read_lines(file):
    lines = []
    with open(file, ‘r’) as f: 
        for line in f:
            lines.append(line.strip(‘\n’).strip(‘\r\n’))
    return lines

Secure coding practices

Python is often used for scripting. An integral part of such scripts is the use of subprocesses. As of this writing, CodeGuru Reviewer makes a limited, but important set of recommendations to make sure that your use of eval functions or subprocesses is secure from potential shell injections. It issues a warning if it detects that the command used in eval or subprocess scenarios might be influenced by external factors. For example, see the following code:

def execute(cmd):
    try:
        retcode = subprocess.call(cmd, shell=True)
        ...
    except OSError as e:
        ...

The following screenshot shows the CodeGuru Reviewer recommendation:

The following screenshot shows CodeGuru Reviewer recommends about potential shell injection vulnerability

The developer accepted this recommendation and made the following fix.

def execute(cmd):
    try:
        retcode = subprocess.call(shlex.quote(cmd), shell=True)
        ...
    except OSError as e:
        ...

As shown in the preceding recommendations, not only are the code issues detected, but a detailed recommendation is also provided on how to fix the issues, along with a link to the Python official documentation. You can provide feedback on recommendations in the CodeGuru Reviewer console or by commenting on the code in a pull request. This feedback helps improve the performance of Reviewer so that the recommendations you see get better over time.

Now let’s take a look at CodeGuru Profiler.

CodeGuru Profiler for Python

Amazon CodeGuru Profiler analyzes your application’s performance characteristics and provides interactive visualizations to show you where your application spends its time. These visualizations a. k. a. flame graphs are a powerful tool to help you troubleshoot which code methods have high latency or are over utilizing your CPU.

Thanks to the new Python agent, you can now use CodeGuru Profiler on your Python applications to investigate performance issues.

The following list summarizes the supported versions as of this writing.

  • AWS Lambda functions: Python3.8, Python3.7, Python3.6
  • Other environments: Python3.9, Python3.8, Python3.7, Python3.6

Onboarding your Python application

For this post, let’s assume you have a Python application running on Amazon Elastic Compute Cloud (Amazon EC2) hosts that you want to profile. To onboard your Python application, complete the following steps:

1. Create a new profiling group in CodeGuru Profiler console called ProfilingGroupForMyApplication. Give access to your Amazon EC2 execution role to submit to this profiling group. See the documentation for details about how to create a Profiling Group.

2. Install the codeguru_profiler_agent module:

pip3 install codeguru_profiler_agent

3. Start the profiler in your application.

An easy way to profile your application is to start your script through the codeguru_profiler_agent module. If you have an app.py script, use the following code:

python -m codeguru_profiler_agent -p ProfilingGroupForMyApplication app.py

Alternatively, you can start the agent manually inside the code. This must be done only one time, preferably in your startup code:

from codeguru_profiler_agent import Profiler

if __name__ == "__main__":
     Profiler(profiling_group_name='ProfilingGroupForMyApplication')
     start_application()    # your code in there....

Onboarding your Python Lambda function

Onboarding for an AWS Lambda function is quite similar.

  1. Create a profiling group called ProfilingGroupForMyLambdaFunction, this time we select “Lambda” for the compute platform. Give access to your Lambda function role to submit to this profiling group. See the documentation for details about how to create a Profiling Group.
  2. Include the codeguru_profiler_agent module in your Lambda function code.
  3. Add the with_lambda_profiler decorator to your handler function:
from codeguru_profiler_agent import with_lambda_profiler

@with_lambda_profiler(profiling_group_name='ProfilingGroupForMyLambdaFunction')
def handler_function(event, context):
      # Your code here

Alternatively, you can profile an existing Lambda function without updating the source code by adding a layer and changing the configuration. For more information, see Profiling your applications that run on AWS Lambda.

Profiling a Lambda function helps you see what is slowing down your code so you can reduce the duration, which reduces the cost and improves latency. You need to have continuous traffic on your function in order to produce a usable profile.

Viewing your profile

After running your profile for some time, you can view it on the CodeGuru console.

Screenshot of Flame graph visualization by CodeGuru Profiler

Each frame in the flame graph shows how much that function contributes to latency. In this example, an outbound call that crosses the network is taking most of the duration in the Lambda function, caching its result would improve the latency.

For more information, see Investigating performance issues with Amazon CodeGuru Profiler.

Supportability for CodeGuru Profiler is documented here.

If you don’t have an application to try CodeGuru Profiler on, you can use the demo application in the following GitHub repo.

Conclusion

This post introduced how to leverage CodeGuru Reviewer to identify hard-to-find code defects in various issue categories and how to onboard your Python applications or Lambda function in CodeGuru Profiler for CPU profiling. Combining both services can help you improve code quality for Python applications. CodeGuru is now available for you to try. For more pricing information, please see Amazon CodeGuru pricing.

 

About the Authors

Neela Sawant is a Senior Applied Scientist in the Amazon CodeGuru team. Her background is building AI-powered solutions to customer problems in a variety of domains such as software, multimedia, and retail. When she isn’t working, you’ll find her exploring the world anew with her toddler and hacking away at AI for social good.

 

 

Pierre Marieu is a Software Development Engineer in the Amazon CodeGuru Profiler team in London. He loves building tools that help the day-to-day life of other software engineers. Previously, he worked at Amadeus IT, building software for the travel industry.

 

 

 

Ran Fu is a Senior Product Manager in the Amazon CodeGuru team. He has a deep customer empathy, and love exploring who are the customers, what are their needs, and why those needs matter. Besides work, you may find him snowboarding in Keystone or Vail, Colorado.

 

Preparing data for ML models using AWS Glue DataBrew in a Jupyter notebook

Post Syndicated from Zayd Simjee original https://aws.amazon.com/blogs/big-data/preparing-data-for-ml-models-using-aws-glue-databrew-in-a-jupyter-notebook/

AWS Glue DataBrew is a new visual data preparation tool that makes it easy for data analysts and data scientists to clean and normalize data to prepare it for analytics and machine learning (ML). In this post, we examine a sample ML use case and show how to use DataBrew and a Jupyter notebook to upload a dataset, clean and normalize the data, and train and publish an ML model. We look for anomalies by applying the Amazon SageMaker Random Cut Forest (RCF) anomaly detection algorithm on a public dataset that records power consumption for more than 300 random households.

Deploying your resources

To make it easier for you to get started, we created an AWS CloudFormation template that automatically configures a Jupyter notebook instance with the required libraries and installs the plugin. We used Amazon Deep Learning AMI to configure the out-of-the-box Jupyter server. This easy deployment is intended to get you started on DataBrew from within a Jupyter environment. The source code for the DataBrew plugin and the CloudFormation template are available in the GitHub repo.

To deploy the solution, you must have a subnet that has internet access and an Amazon Simple Storage Service (Amazon S3) bucket where you want store the data for DataBrew. Select the VPC, subnet, security group, and the S3 bucket that you want to use store the data for DataBrew processing. Provide the Amazon Elastic Compute Cloud (Amazon EC2) key pair if you plan to SSH to the instance.

  1. Launch the following stack:
  2. When the template deployment is complete, on the Outputs tab, choose the URL to open JupyterLab.

Because the Jupyter server is configured with a self-signed SSL certificate, your browser warns you and prompts you to avoid continuing to this website. But because you set this up yourself, it’s safe to continue.

  1. Choose Advanced.
  2. Choose Proceed.
  3. Use the password databrew_demo to log in.

For more information about securing and configuring your Jupyter server, see Set up a Jupyter Notebook Server.

  1. In the Jupyter environment’s left panel, choose the DataBrew logo.
  2. Choose Launch AWS Glue DataBrew.
  3. When the extension loads, choose the Datasets tab in the navigation bar.

Preparing your data using DataBrew

Now that the DataBrew extension is ready to go, we can begin to explore how DataBrew can make data preparation easy. Our source dataset contains data points at 15-minute intervals, and is organized as a series of columns for each household. The dataset is really wide, and the RCF algorithm expects data tuples of date/time, client ID, and consumption value. Additionally, we want to normalize our data to 1-hour intervals. All of this is achieved through DataBrew.

Setting up your dataset and project

To get started, you set up your dataset, import your data, and create a new project.

  1. Download power.consumption.csv from the GitHub repo.
  2. On the Datasets page, choose Connect new dataset.
  3. For Dataset name, enter a name.
  4. In the Connect to new dataset section, choose File upload.
  5. Upload power.consumption.csv.
  6. For Enter S3 destination, enter an S3 path where you can save the file.
  7. Choose Create dataset.

The file may take a few minutes to upload, depending on your internet speed.

  1. On the Datasets page, filter for your created dataset.
  2. Select your dataset and choose Create project with this dataset.

  1. In the Create project wizard, give your project a name.
  2. In the Permissions section, choose the AWS Identity and Access Management (IAM) role created from the CloudFormation template.

You can find the role on the CloudFormation stack’s Resources tab. If you use the default stack name, the role should begin with databrew-jupyter-plugin-demo.

After you create the project, the project view loads, and you’re ready to prepare your data.

Building a recipe for data transformation

A recipe is a series of steps that prepare your data for the RCF algorithm. The algorithm requires three columns: date, client ID, and an integer value. To transform our dataset to contain those three columns, we configure our recipe to do the following:

  1. Unpivot the data to collapse measurements from multiple clients into one column.
  2. Apply the window function to average the 15-minute data points into 1-hour data points.
  3. Filter to keep only values at each hour.
  4. Multiply and floor the results.

Unpivoting the data

To unpivot the data and collapse measurements, complete the following steps:

  1. On the toolbar, choose Pivot.

  1. In the Pivot wizard, select Unpivot: Columns to rows.
  2. For Unpivot columns, choose MT_012, MT_013, MT_131, and MT_132.
  3. For Column name, enter client_id.
  4. For Value column name, enter quarter_hour_consumption.

In the Recipe pane, you can see the action that unpivots the columns. This action can be revisited later and changed. The new columns may not be visible immediately.

  1. To see them and narrow down the visible data to only the relevant columns, choose the arrow next to Viewing.
  2. Deselect all items and select only _c0 and our two new columns, client_id and
    quarter_hour_consumption.

Applying the window function

To apply the window function to average the 15-minute data points into 1-hour data points, complete the following steps:

  1. Choose the quarter_hour_consumption
  2. Choose Functions.
  3. Choose Window functions.
  4. Choose Rolling average.

  1. In the Create column pane, for Number of rows before, enter 0.
  2. For Number of rows after, enter 3.
  3. For Name of column to order by with, choose client_id.
  4. For Destination column, enter hourly_consumption_raw.
  5. Choose Apply.

Filtering to keep only values at each hour

In this step, you rename the date/time column, convert it to string type so that you can do simple filtering, and filter the dataset on the string column for times ending in :00:00.

  1. For the _c0 column, choose the ellipsis icon (…) and choose Rename.

  1. Rename the column to timestamp.
  2. Choose the clock icon and choose string.

  1. With the column selected, choose Filter.
  2. Choose By condition.
  3. Choose Ends with.
  4. Enter the value :00:00.
  5. Choose Apply.

Filtering the column for only values that end with :00:00 leaves you with hourly averages of power consumption per client for every hour.

Multiplying and flooring the results

In this step, you multiply the data by 100 to increase precision and floor the data so that it can be accepted by the RCF algorithm, which only accepts integers.

  1. Choose Functions.
  2. Choose Math functions.
  3. Choose Multiply.
  4. For Value using¸ choose Source columns and value.
  5. For Source column, choose hourly_consumption_raw.
  6. For Destination column, enter hourly_consumption_raw_times_a_hundred.
  7. Choose Apply.

  1. Choose Functions.
  2. Choose Math functions.
  3. Choose Floor.
  4. For Source column, choose hourly_consumption_raw_times_a_hundred.
  5. For Destination column, enter hourly_consumption.
  6. Choose Apply.

This column contains the final, normalized data.

Running the job to transform the data

You’re now ready to transform the data.

  1. Choose Create job.

  1. Enter a job name and choose the dataset we created.
  2. Specify the S3 bucket you provided in the CloudFormation template.
  3. Choose the IAM role that AWS CloudFormation created (which we used earlier to create the project).
  4. Choose Create and run job.

The job may take up to 5 minutes to complete.

On the Job run history page for the job, view the output on the Amazon S3 console by choosing the link in the table.

That’s it, the data is now ready to use when training and deploying our ML model.

Training and deploying the ML model using prepared data

The data was already prepared using DataBrew via the plugin, so the next step is to train an ML model using that data. We provided a sample anomaly detection notebook that you can download.

In this sample notebook, you need to specify the S3 data location where you stored the output data from DataBrew. The notebook uses the IAM role attached to the EC2 instance profile that was created by AWS CloudFormation. You can follow through the notebook and when you provide the right S3 paths, the first step is to filter the specific columns we’re interested in and visualize the time series power consumption data.

The next step is to train a sample anomaly detection model using the SageMaker Random Cut Forest algorithm. We pick one of the time series available in the input Pandas DataFrame and train the anomaly detection model with the hyperparameter feature_dim set to 1, leaving the default values for other hyperparameters. We then create an estimator for Random Cut Forest and fit the model. In a few minutes, the training should be complete. In the next step, we create a predictor and deploy the model to a SageMaker endpoint.

Using the prepared data, we run the prediction and plot the results.

We use the anomaly detection baseline that is two standard deviations away from the mean score. The data shows an anomaly towards the end of the time series. With this information, that timeframe can be further investigated.

Finally, we clean up by deleting the SageMaker endpoint to prevent any ongoing charges.

Conclusion

We’ve walked you through the process of setting up the AWS Glue DataBrew Jupyter plugin in a Jupyter notebook environment. We used the plugin to prepare data, then trained and deployed an ML model in the same Jupyter environment using SageMaker.

Although we used a DLAMI Jupyter environment in this post, the DataBrew Jupyter extension also works on SageMaker notebooks. For installation instructions, see the GitHub repo.

DataBrew makes it easy to iterate through data preparation workflows. The resultant recipes and jobs are duplicable and can be run over discrete, large datasets. The DataBrew Jupyter plugin allows you to prepare your data seamlessly, in context, within your Jupyter notebook.


About the Authors

Zayd Simjee is a software engineer at Amazon. He’s interested in distributed systems, big data, and simplifying developer experience on the Cloud. He’s worked on a few Big Data services at AWS, and most recently completed work on the AWS Glue DataBrew release.

 

 

 

 

As a Principal Solutions Architect at Amazon Web Services, Karthik Sonti works with GSI partners to help enterprises realize transformational business outcomes using artificial intelligence, machine learning and data analytics