Tag Archives: serverless

Serverless Architectures with AWS Lambda: Overview and Best Practices

Post Syndicated from Andrew Baird original https://aws.amazon.com/blogs/architecture/serverless-architectures-with-aws-lambda-overview-and-best-practices/

For some organizations, the idea of “going serverless” can be daunting. But with an understanding of best practices – and the right tools — many serverless applications can be fully functional with only a few lines of code and little else.

Examples of fully-serverless-application use cases include:

  • Web or mobile backends – Create fully-serverless, mobile applications or websites by creating user-facing content in a native mobile application or static web content in an S3 bucket. Then have your front-end content integrate with Amazon API Gateway as a backend service API. Lambda functions will then execute the business logic you’ve written for each of the API Gateway methods in your backend API.
  • Chatbots and virtual assistants – Build new serverless ways to interact with your customers, like customer support assistants and bots ready to engage customers on your company-run social media pages. The Amazon Alexa Skills Kit (ASK) and Amazon Lex have the ability to apply natural-language understanding to user-voice and freeform-text input so that a Lambda function you write can intelligently respond and engage with them.
  • Internet of Things (IoT) backends – AWS IoT has direct-integration for device messages to be routed to and processed by Lambda functions. That means you can implement serverless backends for highly secure, scalable IoT applications for uses like connected consumer appliances and intelligent manufacturing facilities.

Using AWS Lambda as the logic layer of a serverless application can enable faster development speed and greater experimentation – and innovation — than in a traditional, server-based environment.

We recently published the “Serverless Architectures with AWS Lambda: Overview and Best Practices” whitepaper to provide the guidance and best practices you need to write better Lambda functions and build better serverless architectures.

Once you’ve finished reading the whitepaper, below are a couple additional resources I recommend as your next step:

  1. If you would like to better understand some of the architecture pattern possibilities for serverless applications: Thirty Serverless Architectures in 30 Minutes (re:Invent 2017 video)
  2. If you’re ready to get hands-on and build a sample serverless application: AWS Serverless Workshops (GitHub Repository)
  3. If you’ve already built a serverless application and you’d like to ensure your application has been Well Architected: The Serverless Application Lens: AWS Well Architected Framework (Whitepaper)

About the Author

 

Andrew Baird is a Sr. Solutions Architect for AWS. Prior to becoming a Solutions Architect, Andrew was a developer, including time as an SDE with Amazon.com. He has worked on large-scale distributed systems, public-facing APIs, and operations automation.

Implement continuous integration and delivery of serverless AWS Glue ETL applications using AWS Developer Tools

Post Syndicated from Prasad Alle original https://aws.amazon.com/blogs/big-data/implement-continuous-integration-and-delivery-of-serverless-aws-glue-etl-applications-using-aws-developer-tools/

AWS Glue is an increasingly popular way to develop serverless ETL (extract, transform, and load) applications for big data and data lake workloads. Organizations that transform their ETL applications to cloud-based, serverless ETL architectures need a seamless, end-to-end continuous integration and continuous delivery (CI/CD) pipeline: from source code, to build, to deployment, to product delivery. Having a good CI/CD pipeline can help your organization discover bugs before they reach production and deliver updates more frequently. It can also help developers write quality code and automate the ETL job release management process, mitigate risk, and more.

AWS Glue is a fully managed data catalog and ETL service. It simplifies and automates the difficult and time-consuming tasks of data discovery, conversion, and job scheduling. AWS Glue crawls your data sources and constructs a data catalog using pre-built classifiers for popular data formats and data types, including CSV, Apache Parquet, JSON, and more.

When you are developing ETL applications using AWS Glue, you might come across some of the following CI/CD challenges:

  • Iterative development with unit tests
  • Continuous integration and build
  • Pushing the ETL pipeline to a test environment
  • Pushing the ETL pipeline to a production environment
  • Testing ETL applications using real data (live test)
  • Exploring and validating data

In this post, I walk you through a solution that implements a CI/CD pipeline for serverless AWS Glue ETL applications supported by AWS Developer Tools (including AWS CodePipeline, AWS CodeCommit, and AWS CodeBuild) and AWS CloudFormation.

Solution overview

The following diagram shows the pipeline workflow:

This solution uses AWS CodePipeline, which lets you orchestrate and automate the test and deploy stages for ETL application source code. The solution consists of a pipeline that contains the following stages:

1.) Source Control: In this stage, the AWS Glue ETL job source code and the AWS CloudFormation template file for deploying the ETL jobs are both committed to version control. I chose to use AWS CodeCommit for version control.

To get the ETL job source code and AWS CloudFormation template, download the gluedemoetl.zip file. This solution is developed based on a previous post, Build a Data Lake Foundation with AWS Glue and Amazon S3.

2.) LiveTest: In this stage, all resources—including AWS Glue crawlers, jobs, S3 buckets, roles, and other resources that are required for the solution—are provisioned, deployed, live tested, and cleaned up.

The LiveTest stage includes the following actions:

  • Deploy: In this action, all the resources that are required for this solution (crawlers, jobs, buckets, roles, and so on) are provisioned and deployed using an AWS CloudFormation template.
  • AutomatedLiveTest: In this action, all the AWS Glue crawlers and jobs are executed and data exploration and validation tests are performed. These validation tests include, but are not limited to, record counts in both raw tables and transformed tables in the data lake and any other business validations. I used AWS CodeBuild for this action.
  • LiveTestApproval: This action is included for the cases in which a pipeline administrator approval is required to deploy/promote the ETL applications to the next stage. The pipeline pauses in this action until an administrator manually approves the release.
  • LiveTestCleanup: In this action, all the LiveTest stage resources, including test crawlers, jobs, roles, and so on, are deleted using the AWS CloudFormation template. This action helps minimize cost by ensuring that the test resources exist only for the duration of the AutomatedLiveTest and LiveTestApproval

3.) DeployToProduction: In this stage, all the resources are deployed using the AWS CloudFormation template to the production environment.

Try it out

This code pipeline takes approximately 20 minutes to complete the LiveTest test stage (up to the LiveTest approval stage, in which manual approval is required).

To get started with this solution, choose Launch Stack:

This creates the CI/CD pipeline with all of its stages, as described earlier. It performs an initial commit of the sample AWS Glue ETL job source code to trigger the first release change.

In the AWS CloudFormation console, choose Create. After the template finishes creating resources, you see the pipeline name on the stack Outputs tab.

After that, open the CodePipeline console and select the newly created pipeline. Initially, your pipeline’s CodeCommit stage shows that the source action failed.

Allow a few minutes for your new pipeline to detect the initial commit applied by the CloudFormation stack creation. As soon as the commit is detected, your pipeline starts. You will see the successful stage completion status as soon as the CodeCommit source stage runs.

In the CodeCommit console, choose Code in the navigation pane to view the solution files.

Next, you can watch how the pipeline goes through the LiveTest stage of the deploy and AutomatedLiveTest actions, until it finally reaches the LiveTestApproval action.

At this point, if you check the AWS CloudFormation console, you can see that a new template has been deployed as part of the LiveTest deploy action.

At this point, make sure that the AWS Glue crawlers and the AWS Glue job ran successfully. Also check whether the corresponding databases and external tables have been created in the AWS Glue Data Catalog. Then verify that the data is validated using Amazon Athena, as shown following.

Open the AWS Glue console, and choose Databases in the navigation pane. You will see the following databases in the Data Catalog:

Open the Amazon Athena console, and run the following queries. Verify that the record counts are matching.

SELECT count(*) FROM "nycitytaxi_gluedemocicdtest"."data";
SELECT count(*) FROM "nytaxiparquet_gluedemocicdtest"."datalake";

The following shows the raw data:

The following shows the transformed data:

The pipeline pauses the action until the release is approved. After validating the data, manually approve the revision on the LiveTestApproval action on the CodePipeline console.

Add comments as needed, and choose Approve.

The LiveTestApproval stage now appears as Approved on the console.

After the revision is approved, the pipeline proceeds to use the AWS CloudFormation template to destroy the resources that were deployed in the LiveTest deploy action. This helps reduce cost and ensures a clean test environment on every deployment.

Production deployment is the final stage. In this stage, all the resources—AWS Glue crawlers, AWS Glue jobs, Amazon S3 buckets, roles, and so on—are provisioned and deployed to the production environment using the AWS CloudFormation template.

After successfully running the whole pipeline, feel free to experiment with it by changing the source code stored on AWS CodeCommit. For example, if you modify the AWS Glue ETL job to generate an error, it should make the AutomatedLiveTest action fail. Or if you change the AWS CloudFormation template to make its creation fail, it should affect the LiveTest deploy action. The objective of the pipeline is to guarantee that all changes that are deployed to production are guaranteed to work as expected.

Conclusion

In this post, you learned how easy it is to implement CI/CD for serverless AWS Glue ETL solutions with AWS developer tools like AWS CodePipeline and AWS CodeBuild at scale. Implementing such solutions can help you accelerate ETL development and testing at your organization.

If you have questions or suggestions, please comment below.

 


Additional Reading

If you found this post useful, be sure to check out Implement Continuous Integration and Delivery of Apache Spark Applications using AWS and Build a Data Lake Foundation with AWS Glue and Amazon S3.

 


About the Authors

Prasad Alle is a Senior Big Data Consultant with AWS Professional Services. He spends his time leading and building scalable, reliable Big data, Machine learning, Artificial Intelligence and IoT solutions for AWS Enterprise and Strategic customers. His interests extend to various technologies such as Advanced Edge Computing, Machine learning at Edge. In his spare time, he enjoys spending time with his family.

 
Luis Caro is a Big Data Consultant for AWS Professional Services. He works with our customers to provide guidance and technical assistance on big data projects, helping them improving the value of their solutions when using AWS.

 

 

 

Implementing safe AWS Lambda deployments with AWS CodeDeploy

Post Syndicated from Chris Munns original https://aws.amazon.com/blogs/compute/implementing-safe-aws-lambda-deployments-with-aws-codedeploy/

This post courtesy of George Mao, AWS Senior Serverless Specialist – Solutions Architect

AWS Lambda and AWS CodeDeploy recently made it possible to automatically shift incoming traffic between two function versions based on a preconfigured rollout strategy. This new feature allows you to gradually shift traffic to the new function. If there are any issues with the new code, you can quickly rollback and control the impact to your application.

Previously, you had to manually move 100% of traffic from the old version to the new version. Now, you can have CodeDeploy automatically execute pre- or post-deployment tests and automate a gradual rollout strategy. Traffic shifting is built right into the AWS Serverless Application Model (SAM), making it easy to define and deploy your traffic shifting capabilities. SAM is an extension of AWS CloudFormation that provides a simplified way of defining serverless applications.

In this post, I show you how to use SAM, CloudFormation, and CodeDeploy to accomplish an automated rollout strategy for safe Lambda deployments.

Scenario

For this walkthrough, you write a Lambda application that returns a count of the S3 buckets that you own. You deploy it and use it in production. Later on, you receive requirements that tell you that you need to change your Lambda application to count only buckets that begin with the letter “a”.

Before you make the change, you need to be sure that your new Lambda application works as expected. If it does have issues, you want to minimize the number of impacted users and roll back easily. To accomplish this, you create a deployment process that publishes the new Lambda function, but does not send any traffic to it. You use CodeDeploy to execute a PreTraffic test to ensure that your new function works as expected. After the test succeeds, CodeDeploy automatically shifts traffic gradually to the new version of the Lambda function.

Your Lambda function is exposed as a REST service via an Amazon API Gateway deployment. This makes it easy to test and integrate.

Prerequisites

To execute the SAM and CloudFormation deployment, you must have the following IAM permissions:

  • cloudformation:*
  • lambda:*
  • codedeploy:*
  • iam:create*

You may use the AWS SAM Local CLI or the AWS CLI to package and deploy your Lambda application. If you choose to use SAM Local, be sure to install it onto your system. For more information, see AWS SAM Local Installation.

All of the code used in this post can be found in this GitHub repository: https://github.com/aws-samples/aws-safe-lambda-deployments.

Walkthrough

For this post, use SAM to define your resources because it comes with built-in CodeDeploy support for safe Lambda deployments.  The deployment is handled and automated by CloudFormation.

SAM allows you to define your Serverless applications in a simple and concise fashion, because it automatically creates all necessary resources behind the scenes. For example, if you do not define an execution role for a Lambda function, SAM automatically creates one. SAM also creates the CodeDeploy application necessary to drive the traffic shifting, as well as the IAM service role that CodeDeploy uses to execute all actions.

Create a SAM template

To get started, write your SAM template and call it template.yaml.

AWSTemplateFormatVersion : '2010-09-09'
Transform: AWS::Serverless-2016-10-31
Description: An example SAM template for Lambda Safe Deployments.

Resources:

  returnS3Buckets:
    Type: AWS::Serverless::Function
    Properties:
      Handler: returnS3Buckets.handler
      Runtime: nodejs6.10
      AutoPublishAlias: live
      Policies:
        - Version: "2012-10-17"
          Statement: 
          - Effect: "Allow"
            Action: 
              - "s3:ListAllMyBuckets"
            Resource: '*'
      DeploymentPreference:
          Type: Linear10PercentEvery1Minute
          Hooks:
            PreTraffic: !Ref preTrafficHook
      Events:
        Api:
          Type: Api
          Properties:
            Path: /test
            Method: get

  preTrafficHook:
    Type: AWS::Serverless::Function
    Properties:
      Handler: preTrafficHook.handler
      Policies:
        - Version: "2012-10-17"
          Statement: 
          - Effect: "Allow"
            Action: 
              - "codedeploy:PutLifecycleEventHookExecutionStatus"
            Resource:
              !Sub 'arn:aws:codedeploy:${AWS::Region}:${AWS::AccountId}:deploymentgroup:${ServerlessDeploymentApplication}/*'
        - Version: "2012-10-17"
          Statement: 
          - Effect: "Allow"
            Action: 
              - "lambda:InvokeFunction"
            Resource: !Ref returnS3Buckets.Version
      Runtime: nodejs6.10
      FunctionName: 'CodeDeployHook_preTrafficHook'
      DeploymentPreference:
        Enabled: false
      Timeout: 5
      Environment:
        Variables:
          NewVersion: !Ref returnS3Buckets.Version

This template creates two functions:

  • returnS3Buckets
  • preTrafficHook

The returnS3Buckets function is where your application logic lives. It’s a simple piece of code that uses the AWS SDK for JavaScript in Node.JS to call the Amazon S3 listBuckets API action and return the number of buckets.

'use strict';

var AWS = require('aws-sdk');
var s3 = new AWS.S3();

exports.handler = (event, context, callback) => {
	console.log("I am here! " + context.functionName  +  ":"  +  context.functionVersion);

	s3.listBuckets(function (err, data){
		if(err){
			console.log(err, err.stack);
			callback(null, {
				statusCode: 500,
				body: "Failed!"
			});
		}
		else{
			var allBuckets = data.Buckets;

			console.log("Total buckets: " + allBuckets.length);
			callback(null, {
				statusCode: 200,
				body: allBuckets.length
			});
		}
	});	
}

Review the key parts of the SAM template that defines returnS3Buckets:

  • The AutoPublishAlias attribute instructs SAM to automatically publish a new version of the Lambda function for each new deployment and link it to the live alias.
  • The Policies attribute specifies additional policy statements that SAM adds onto the automatically generated IAM role for this function. The first statement provides the function with permission to call listBuckets.
  • The DeploymentPreference attribute configures the type of rollout pattern to use. In this case, you are shifting traffic in a linear fashion, moving 10% of traffic every minute to the new version. For more information about supported patterns, see Serverless Application Model: Traffic Shifting Configurations.
  • The Hooks attribute specifies that you want to execute the preTrafficHook Lambda function before CodeDeploy automatically begins shifting traffic. This function should perform validation testing on the newly deployed Lambda version. This function invokes the new Lambda function and checks the results. If you’re satisfied with the tests, instruct CodeDeploy to proceed with the rollout via an API call to: codedeploy.putLifecycleEventHookExecutionStatus.
  • The Events attribute defines an API-based event source that can trigger this function. It accepts requests on the /test path using an HTTP GET method.
'use strict';

const AWS = require('aws-sdk');
const codedeploy = new AWS.CodeDeploy({apiVersion: '2014-10-06'});
var lambda = new AWS.Lambda();

exports.handler = (event, context, callback) => {

	console.log("Entering PreTraffic Hook!");
	
	// Read the DeploymentId & LifecycleEventHookExecutionId from the event payload
    var deploymentId = event.DeploymentId;
	var lifecycleEventHookExecutionId = event.LifecycleEventHookExecutionId;

	var functionToTest = process.env.NewVersion;
	console.log("Testing new function version: " + functionToTest);

	// Perform validation of the newly deployed Lambda version
	var lambdaParams = {
		FunctionName: functionToTest,
		InvocationType: "RequestResponse"
	};

	var lambdaResult = "Failed";
	lambda.invoke(lambdaParams, function(err, data) {
		if (err){	// an error occurred
			console.log(err, err.stack);
			lambdaResult = "Failed";
		}
		else{	// successful response
			var result = JSON.parse(data.Payload);
			console.log("Result: " +  JSON.stringify(result));

			// Check the response for valid results
			// The response will be a JSON payload with statusCode and body properties. ie:
			// {
			//		"statusCode": 200,
			//		"body": 51
			// }
			if(result.body == 9){	
				lambdaResult = "Succeeded";
				console.log ("Validation testing succeeded!");
			}
			else{
				lambdaResult = "Failed";
				console.log ("Validation testing failed!");
			}

			// Complete the PreTraffic Hook by sending CodeDeploy the validation status
			var params = {
				deploymentId: deploymentId,
				lifecycleEventHookExecutionId: lifecycleEventHookExecutionId,
				status: lambdaResult // status can be 'Succeeded' or 'Failed'
			};
			
			// Pass AWS CodeDeploy the prepared validation test results.
			codedeploy.putLifecycleEventHookExecutionStatus(params, function(err, data) {
				if (err) {
					// Validation failed.
					console.log('CodeDeploy Status update failed');
					console.log(err, err.stack);
					callback("CodeDeploy Status update failed");
				} else {
					// Validation succeeded.
					console.log('Codedeploy status updated successfully');
					callback(null, 'Codedeploy status updated successfully');
				}
			});
		}  
	});
}

The hook is hardcoded to check that the number of S3 buckets returned is 9.

Review the key parts of the SAM template that defines preTrafficHook:

  • The Policies attribute specifies additional policy statements that SAM adds onto the automatically generated IAM role for this function. The first statement provides permissions to call the CodeDeploy PutLifecycleEventHookExecutionStatus API action. The second statement provides permissions to invoke the specific version of the returnS3Buckets function to test
  • This function has traffic shifting features disabled by setting the DeploymentPreference option to false.
  • The FunctionName attribute explicitly tells CloudFormation what to name the function. Otherwise, CloudFormation creates the function with the default naming convention: [stackName]-[FunctionName]-[uniqueID].  Name the function with the “CodeDeployHook_” prefix because the CodeDeployServiceRole role only allows InvokeFunction on functions named with that prefix.
  • Set the Timeout attribute to allow enough time to complete your validation tests.
  • Use an environment variable to inject the ARN of the newest deployed version of the returnS3Buckets function. The ARN allows the function to know the specific version to invoke and perform validation testing on.

Deploy the function

Your SAM template is all set and the code is written—you’re ready to deploy the function for the first time. Here’s how to do it via the SAM CLI. Replace “sam” with “cloudformation” to use CloudFormation instead.

First, package the function. This command returns a CloudFormation importable file, packaged.yaml.

sam package –template-file template.yaml –s3-bucket mybucket –output-template-file packaged.yaml

Now deploy everything:

sam deploy –template-file packaged.yaml –stack-name mySafeDeployStack –capabilities CAPABILITY_IAM

At this point, both Lambda functions have been deployed within the CloudFormation stack mySafeDeployStack. The returnS3Buckets has been deployed as Version 1:

SAM automatically created a few things, including the CodeDeploy application, with the deployment pattern that you specified (Linear10PercentEvery1Minute). There is currently one deployment group, with no action, because no deployments have occurred. SAM also created the IAM service role that this CodeDeploy application uses:

There is a single managed policy attached to this role, which allows CodeDeploy to invoke any Lambda function that begins with “CodeDeployHook_”.

An API has been set up called safeDeployStack. It targets your Lambda function with the /test resource using the GET method. When you test the endpoint, API Gateway executes the returnS3Buckets function and it returns the number of S3 buckets that you own. In this case, it’s 51.

Publish a new Lambda function version

Now implement the requirements change, which is to make returnS3Buckets count only buckets that begin with the letter “a”. The code now looks like the following (see returnS3BucketsNew.js in GitHub):

'use strict';

var AWS = require('aws-sdk');
var s3 = new AWS.S3();

exports.handler = (event, context, callback) => {
	console.log("I am here! " + context.functionName  +  ":"  +  context.functionVersion);

	s3.listBuckets(function (err, data){
		if(err){
			console.log(err, err.stack);
			callback(null, {
				statusCode: 500,
				body: "Failed!"
			});
		}
		else{
			var allBuckets = data.Buckets;

			console.log("Total buckets: " + allBuckets.length);
			//callback(null, allBuckets.length);

			//  New Code begins here
			var counter=0;
			for(var i  in allBuckets){
				if(allBuckets[i].Name[0] === "a")
					counter++;
			}
			console.log("Total buckets starting with a: " + counter);

			callback(null, {
				statusCode: 200,
				body: counter
			});
			
		}
	});	
}

Repackage and redeploy with the same two commands as earlier:

sam package –template-file template.yaml –s3-bucket mybucket –output-template-file packaged.yaml
	
sam deploy –template-file packaged.yaml –stack-name mySafeDeployStack –capabilities CAPABILITY_IAM

CloudFormation understands that this is a stack update instead of an entirely new stack. You can see that reflected in the CloudFormation console:

During the update, CloudFormation deploys the new Lambda function as version 2 and adds it to the “live” alias. There is no traffic routing there yet. CodeDeploy now takes over to begin the safe deployment process.

The first thing CodeDeploy does is invoke the preTrafficHook function. Verify that this happened by reviewing the Lambda logs and metrics:

The function should progress successfully, invoke Version 2 of returnS3Buckets, and finally invoke the CodeDeploy API with a success code. After this occurs, CodeDeploy begins the predefined rollout strategy. Open the CodeDeploy console to review the deployment progress (Linear10PercentEvery1Minute):

Verify the traffic shift

During the deployment, verify that the traffic shift has started to occur by running the test periodically. As the deployment shifts towards the new version, a larger percentage of the responses return 9 instead of 51. These numbers match the S3 buckets.

A minute later, you see 10% more traffic shifting to the new version. The whole process takes 10 minutes to complete. After completion, open the Lambda console and verify that the “live” alias now points to version 2:

After 10 minutes, the deployment is complete and CodeDeploy signals success to CloudFormation and completes the stack update.

Check the results

If you invoke the function alias manually, you see the results of the new implementation.

aws lambda invoke –function [lambda arn to live alias] out.txt

You can also execute the prod stage of your API and verify the results by issuing an HTTP GET to the invoke URL:

Summary

This post has shown you how you can safely automate your Lambda deployments using the Lambda traffic shifting feature. You used the Serverless Application Model (SAM) to define your Lambda functions and configured CodeDeploy to manage your deployment patterns. Finally, you used CloudFormation to automate the deployment and updates to your function and PreTraffic hook.

Now that you know all about this new feature, you’re ready to begin automating Lambda deployments with confidence that things will work as designed. I look forward to hearing about what you’ve built with the AWS Serverless Platform.

AWS AppSync – Production-Ready with Six New Features

Post Syndicated from Jeff Barr original https://aws.amazon.com/blogs/aws/aws-appsync-production-ready-with-six-new-features/

If you build (or want to build) data-driven web and mobile apps and need real-time updates and the ability to work offline, you should take a look at AWS AppSync. Announced in preview form at AWS re:Invent 2017 and described in depth here, AWS AppSync is designed for use in iOS, Android, JavaScript, and React Native apps. AWS AppSync is built around GraphQL, an open, standardized query language that makes it easy for your applications to request the precise data that they need from the cloud.

I’m happy to announce that the preview period is over and that AWS AppSync is now generally available and production-ready, with six new features that will simplify and streamline your application development process:

Console Log Access – You can now see the CloudWatch Logs entries that are created when you test your GraphQL queries, mutations, and subscriptions from within the AWS AppSync Console.

Console Testing with Mock Data – You can now create and use mock context objects in the console for testing purposes.

Subscription Resolvers – You can now create resolvers for AWS AppSync subscription requests, just as you can already do for query and mutate requests.

Batch GraphQL Operations for DynamoDB – You can now make use of DynamoDB’s batch operations (BatchGetItem and BatchWriteItem) across one or more tables. in your resolver functions.

CloudWatch Support – You can now use Amazon CloudWatch Metrics and CloudWatch Logs to monitor calls to the AWS AppSync APIs.

CloudFormation Support – You can now define your schemas, data sources, and resolvers using AWS CloudFormation templates.

A Brief AppSync Review
Before diving in to the new features, let’s review the process of creating an AWS AppSync API, starting from the console. I click Create API to begin:

I enter a name for my API and (for demo purposes) choose to use the Sample schema:

The schema defines a collection of GraphQL object types. Each object type has a set of fields, with optional arguments:

If I was creating an API of my own I would enter my schema at this point. Since I am using the sample, I don’t need to do this. Either way, I click on Create to proceed:

The GraphQL schema type defines the entry points for the operations on the data. All of the data stored on behalf of a particular schema must be accessible using a path that begins at one of these entry points. The console provides me with an endpoint and key for my API:

It also provides me with guidance and a set of fully functional sample apps that I can clone:

When I clicked Create, AWS AppSync created a pair of Amazon DynamoDB tables for me. I can click Data Sources to see them:

I can also see and modify my schema, issue queries, and modify an assortment of settings for my API.

Let’s take a quick look at each new feature…

Console Log Access
The AWS AppSync Console already allows me to issue queries and to see the results, and now provides access to relevant log entries.In order to see the entries, I must enable logs (as detailed below), open up the LOGS, and check the checkbox. Here’s a simple mutation query that adds a new event. I enter the query and click the arrow to test it:

I can click VIEW IN CLOUDWATCH for a more detailed view:

To learn more, read Test and Debug Resolvers.

Console Testing with Mock Data
You can now create a context object in the console where it will be passed to one of your resolvers for testing purposes. I’ll add a testResolver item to my schema:

Then I locate it on the right-hand side of the Schema page and click Attach:

I choose a data source (this is for testing and the actual source will not be accessed), and use the Put item mapping template:

Then I click Select test context, choose Create New Context, assign a name to my test content, and click Save (as you can see, the test context contains the arguments from the query along with values to be returned for each field of the result):

After I save the new Resolver, I click Test to see the request and the response:

Subscription Resolvers
Your AWS AppSync application can monitor changes to any data source using the @aws_subscribe GraphQL schema directive and defining a Subscription type. The AWS AppSync client SDK connects to AWS AppSync using MQTT over Websockets and the application is notified after each mutation. You can now attach resolvers (which convert GraphQL payloads into the protocol needed by the underlying storage system) to your subscription fields and perform authorization checks when clients attempt to connect. This allows you to perform the same fine grained authorization routines across queries, mutations, and subscriptions.

To learn more about this feature, read Real-Time Data.

Batch GraphQL Operations
Your resolvers can now make use of DynamoDB batch operations that span one or more tables in a region. This allows you to use a list of keys in a single query, read records multiple tables, write records in bulk to multiple tables, and conditionally write or delete related records across multiple tables.

In order to use this feature the IAM role that you use to access your tables must grant access to DynamoDB’s BatchGetItem and BatchPutItem functions.

To learn more, read the DynamoDB Batch Resolvers tutorial.

CloudWatch Logs Support
You can now tell AWS AppSync to log API requests to CloudWatch Logs. Click on Settings and Enable logs, then choose the IAM role and the log level:

CloudFormation Support
You can use the following CloudFormation resource types in your templates to define AWS AppSync resources:

AWS::AppSync::GraphQLApi – Defines an AppSync API in terms of a data source (an Amazon Elasticsearch Service domain or a DynamoDB table).

AWS::AppSync::ApiKey – Defines the access key needed to access the data source.

AWS::AppSync::GraphQLSchema – Defines a GraphQL schema.

AWS::AppSync::DataSource – Defines a data source.

AWS::AppSync::Resolver – Defines a resolver by referencing a schema and a data source, and includes a mapping template for requests.

Here’s a simple schema definition in YAML form:

  AppSyncSchema:
    Type: "AWS::AppSync::GraphQLSchema"
    DependsOn:
      - AppSyncGraphQLApi
    Properties:
      ApiId: !GetAtt AppSyncGraphQLApi.ApiId
      Definition: |
        schema {
          query: Query
          mutation: Mutation
        }
        type Query {
          singlePost(id: ID!): Post
          allPosts: [Post]
        }
        type Mutation {
          putPost(id: ID!, title: String!): Post
        }
        type Post {
          id: ID!
          title: String!
        }

Available Now
These new features are available now and you can start using them today! Here are a couple of blog posts and other resources that you might find to be of interest:

Jeff;

 

 

How to retain system tables’ data spanning multiple Amazon Redshift clusters and run cross-cluster diagnostic queries

Post Syndicated from Karthik Sonti original https://aws.amazon.com/blogs/big-data/how-to-retain-system-tables-data-spanning-multiple-amazon-redshift-clusters-and-run-cross-cluster-diagnostic-queries/

Amazon Redshift is a data warehouse service that logs the history of the system in STL log tables. The STL log tables manage disk space by retaining only two to five days of log history, depending on log usage and available disk space.

To retain STL tables’ data for an extended period, you usually have to create a replica table for every system table. Then, for each you load the data from the system table into the replica at regular intervals. By maintaining replica tables for STL tables, you can run diagnostic queries on historical data from the STL tables. You then can derive insights from query execution times, query plans, and disk-spill patterns, and make better cluster-sizing decisions. However, refreshing replica tables with live data from STL tables at regular intervals requires schedulers such as Cron or AWS Data Pipeline. Also, these tables are specific to one cluster and they are not accessible after the cluster is terminated. This is especially true for transient Amazon Redshift clusters that last for only a finite period of ad hoc query execution.

In this blog post, I present a solution that exports system tables from multiple Amazon Redshift clusters into an Amazon S3 bucket. This solution is serverless, and you can schedule it as frequently as every five minutes. The AWS CloudFormation deployment template that I provide automates the solution setup in your environment. The system tables’ data in the Amazon S3 bucket is partitioned by cluster name and query execution date to enable efficient joins in cross-cluster diagnostic queries.

I also provide another CloudFormation template later in this post. This second template helps to automate the creation of tables in the AWS Glue Data Catalog for the system tables’ data stored in Amazon S3. After the system tables are exported to Amazon S3, you can run cross-cluster diagnostic queries on the system tables’ data and derive insights about query executions in each Amazon Redshift cluster. You can do this using Amazon QuickSight, Amazon Athena, Amazon EMR, or Amazon Redshift Spectrum.

You can find all the code examples in this post, including the CloudFormation templates, AWS Glue extract, transform, and load (ETL) scripts, and the resolution steps for common errors you might encounter in this GitHub repository.

Solution overview

The solution in this post uses AWS Glue to export system tables’ log data from Amazon Redshift clusters into Amazon S3. The AWS Glue ETL jobs are invoked at a scheduled interval by AWS Lambda. AWS Systems Manager, which provides secure, hierarchical storage for configuration data management and secrets management, maintains the details of Amazon Redshift clusters for which the solution is enabled. The last-fetched time stamp values for the respective cluster-table combination are maintained in an Amazon DynamoDB table.

The following diagram covers the key steps involved in this solution.

The solution as illustrated in the preceding diagram flows like this:

  1. The Lambda function, invoke_rs_stl_export_etl, is triggered at regular intervals, as controlled by Amazon CloudWatch. It’s triggered to look up the AWS Systems Manager parameter store to get the details of the Amazon Redshift clusters for which the system table export is enabled.
  2. The same Lambda function, based on the Amazon Redshift cluster details obtained in step 1, invokes the AWS Glue ETL job designated for the Amazon Redshift cluster. If an ETL job for the cluster is not found, the Lambda function creates one.
  3. The ETL job invoked for the Amazon Redshift cluster gets the cluster credentials from the parameter store. It gets from the DynamoDB table the last exported time stamp of when each of the system tables was exported from the respective Amazon Redshift cluster.
  4. The ETL job unloads the system tables’ data from the Amazon Redshift cluster into an Amazon S3 bucket.
  5. The ETL job updates the DynamoDB table with the last exported time stamp value for each system table exported from the Amazon Redshift cluster.
  6. The Amazon Redshift cluster system tables’ data is available in Amazon S3 and is partitioned by cluster name and date for running cross-cluster diagnostic queries.

Understanding the configuration data

This solution uses AWS Systems Manager parameter store to store the Amazon Redshift cluster credentials securely. The parameter store also securely stores other configuration information that the AWS Glue ETL job needs for extracting and storing system tables’ data in Amazon S3. Systems Manager comes with a default AWS Key Management Service (AWS KMS) key that it uses to encrypt the password component of the Amazon Redshift cluster credentials.

The following table explains the global parameters and cluster-specific parameters required in this solution. The global parameters are defined once and applicable at the overall solution level. The cluster-specific parameters are specific to an Amazon Redshift cluster and repeat for each cluster for which you enable this post’s solution. The CloudFormation template explained later in this post creates these parameters as part of the deployment process.

Parameter name Type Description
Global parametersdefined once and applied to all jobs
redshift_query_logs.global.s3_prefix String The Amazon S3 path where the query logs are exported. Under this path, each exported table is partitioned by cluster name and date.
redshift_query_logs.global.tempdir String The Amazon S3 path that AWS Glue ETL jobs use for temporarily staging the data.
redshift_query_logs.global.role> String The name of the role that the AWS Glue ETL jobs assume. Just the role name is sufficient. The complete Amazon Resource Name (ARN) is not required.
redshift_query_logs.global.enabled_cluster_list StringList A comma-separated list of cluster names for which system tables’ data export is enabled. This gives flexibility for a user to exclude certain clusters.
Cluster-specific parametersfor each cluster specified in the enabled_cluster_list parameter
redshift_query_logs.<<cluster_name>>.connection String The name of the AWS Glue Data Catalog connection to the Amazon Redshift cluster. For example, if the cluster name is product_warehouse, the entry is redshift_query_logs.product_warehouse.connection.
redshift_query_logs.<<cluster_name>>.user String The user name that AWS Glue uses to connect to the Amazon Redshift cluster.
redshift_query_logs.<<cluster_name>>.password Secure String The password that AWS Glue uses to connect the Amazon Redshift cluster’s encrypted-by key that is managed in AWS KMS.

For example, suppose that you have two Amazon Redshift clusters, product-warehouse and category-management, for which the solution described in this post is enabled. In this case, the parameters shown in the following screenshot are created by the solution deployment CloudFormation template in the AWS Systems Manager parameter store.

Solution deployment

To make it easier for you to get started, I created a CloudFormation template that automatically configures and deploys the solution—only one step is required after deployment.

Prerequisites

To deploy the solution, you must have one or more Amazon Redshift clusters in a private subnet. This subnet must have a network address translation (NAT) gateway or a NAT instance configured, and also a security group with a self-referencing inbound rule for all TCP ports. For more information about why AWS Glue ETL needs the configuration it does, described previously, see Connecting to a JDBC Data Store in a VPC in the AWS Glue documentation.

To start the deployment, launch the CloudFormation template:

CloudFormation stack parameters

The following table lists and describes the parameters for deploying the solution to export query logs from multiple Amazon Redshift clusters.

Property Default Description
S3Bucket mybucket The bucket this solution uses to store the exported query logs, stage code artifacts, and perform unloads from Amazon Redshift. For example, the mybucket/extract_rs_logs/data bucket is used for storing all the exported query logs for each system table partitioned by the cluster. The mybucket/extract_rs_logs/temp/ bucket is used for temporarily staging the unloaded data from Amazon Redshift. The mybucket/extract_rs_logs/code bucket is used for storing all the code artifacts required for Lambda and the AWS Glue ETL jobs.
ExportEnabledRedshiftClusters Requires Input A comma-separated list of cluster names from which the system table logs need to be exported.
DataStoreSecurityGroups Requires Input A list of security groups with an inbound rule to the Amazon Redshift clusters provided in the parameter, ExportEnabledClusters. These security groups should also have a self-referencing inbound rule on all TCP ports, as explained on Connecting to a JDBC Data Store in a VPC.

After you launch the template and create the stack, you see that the following resources have been created:

  1. AWS Glue connections for each Amazon Redshift cluster you provided in the CloudFormation stack parameter, ExportEnabledRedshiftClusters.
  2. All parameters required for this solution created in the parameter store.
  3. The Lambda function that invokes the AWS Glue ETL jobs for each configured Amazon Redshift cluster at a regular interval of five minutes.
  4. The DynamoDB table that captures the last exported time stamps for each exported cluster-table combination.
  5. The AWS Glue ETL jobs to export query logs from each Amazon Redshift cluster provided in the CloudFormation stack parameter, ExportEnabledRedshiftClusters.
  6. The IAM roles and policies required for the Lambda function and AWS Glue ETL jobs.

After the deployment

For each Amazon Redshift cluster for which you enabled the solution through the CloudFormation stack parameter, ExportEnabledRedshiftClusters, the automated deployment includes temporary credentials that you must update after the deployment:

  1. Go to the parameter store.
  2. Note the parameters <<cluster_name>>.user and redshift_query_logs.<<cluster_name>>.password that correspond to each Amazon Redshift cluster for which you enabled this solution. Edit these parameters to replace the placeholder values with the right credentials.

For example, if product-warehouse is one of the clusters for which you enabled system table export, you edit these two parameters with the right user name and password and choose Save parameter.

Querying the exported system tables

Within a few minutes after the solution deployment, you should see Amazon Redshift query logs being exported to the Amazon S3 location, <<S3Bucket_you_provided>>/extract_redshift_query_logs/data/. In that bucket, you should see the eight system tables partitioned by customer name and date: stl_alert_event_log, stl_dlltext, stl_explain, stl_query, stl_querytext, stl_scan, stl_utilitytext, and stl_wlm_query.

To run cross-cluster diagnostic queries on the exported system tables, create external tables in the AWS Glue Data Catalog. To make it easier for you to get started, I provide a CloudFormation template that creates an AWS Glue crawler, which crawls the exported system tables stored in Amazon S3 and builds the external tables in the AWS Glue Data Catalog.

Launch this CloudFormation template to create external tables that correspond to the Amazon Redshift system tables. S3Bucket is the only input parameter required for this stack deployment. Provide the same Amazon S3 bucket name where the system tables’ data is being exported. After you successfully create the stack, you can see the eight tables in the database, redshift_query_logs_db, as shown in the following screenshot.

Now, navigate to the Athena console to run cross-cluster diagnostic queries. The following screenshot shows a diagnostic query executed in Athena that retrieves query alerts logged across multiple Amazon Redshift clusters.

You can build the following example Amazon QuickSight dashboard by running cross-cluster diagnostic queries on Athena to identify the hourly query count and the key query alert events across multiple Amazon Redshift clusters.

How to extend the solution

You can extend this post’s solution in two ways:

  • Add any new Amazon Redshift clusters that you spin up after you deploy the solution.
  • Add other system tables or custom query results to the list of exports from an Amazon Redshift cluster.

Extend the solution to other Amazon Redshift clusters

To extend the solution to more Amazon Redshift clusters, add the three cluster-specific parameters in the AWS Systems Manager parameter store following the guidelines earlier in this post. Modify the redshift_query_logs.global.enabled_cluster_list parameter to append the new cluster to the comma-separated string.

Extend the solution to add other tables or custom queries to an Amazon Redshift cluster

The current solution ships with the export functionality for the following Amazon Redshift system tables:

  • stl_alert_event_log
  • stl_dlltext
  • stl_explain
  • stl_query
  • stl_querytext
  • stl_scan
  • stl_utilitytext
  • stl_wlm_query

You can easily add another system table or custom query by adding a few lines of code to the AWS Glue ETL job, <<cluster-name>_extract_rs_query_logs. For example, suppose that from the product-warehouse Amazon Redshift cluster you want to export orders greater than $2,000. To do so, add the following five lines of code to the AWS Glue ETL job product-warehouse_extract_rs_query_logs, where product-warehouse is your cluster name:

  1. Get the last-processed time-stamp value. The function creates a value if it doesn’t already exist.

salesLastProcessTSValue = functions.getLastProcessedTSValue(trackingEntry=”mydb.sales_2000",job_configs=job_configs)

  1. Run the custom query with the time stamp.

returnDF=functions.runQuery(query="select * from sales s join order o where o.order_amnt > 2000 and sale_timestamp > '{}'".format (salesLastProcessTSValue) ,tableName="mydb.sales_2000",job_configs=job_configs)

  1. Save the results to Amazon S3.

functions.saveToS3(dataframe=returnDF,s3Prefix=s3Prefix,tableName="mydb.sales_2000",partitionColumns=["sale_date"],job_configs=job_configs)

  1. Get the latest time-stamp value from the returned data frame in Step 2.

latestTimestampVal=functions.getMaxValue(returnDF,"sale_timestamp",job_configs)

  1. Update the last-processed time-stamp value in the DynamoDB table.

functions.updateLastProcessedTSValue(“mydb.sales_2000",latestTimestampVal[0],job_configs)

Conclusion

In this post, I demonstrate a serverless solution to retain the system tables’ log data across multiple Amazon Redshift clusters. By using this solution, you can incrementally export the data from system tables into Amazon S3. By performing this export, you can build cross-cluster diagnostic queries, build audit dashboards, and derive insights into capacity planning by using services such as Athena. I also demonstrate how you can extend this solution to other ad hoc query use cases or tables other than system tables by adding a few lines of code.


Additional Reading

If you found this post useful, be sure to check out Using Amazon Redshift Spectrum, Amazon Athena, and AWS Glue with Node.js in Production and Amazon Redshift – 2017 Recap.


About the Author

Karthik Sonti is a senior big data architect at Amazon Web Services. He helps AWS customers build big data and analytical solutions and provides guidance on architecture and best practices.

 

 

 

 

AWS Online Tech Talks – April & Early May 2018

Post Syndicated from Betsy Chernoff original https://aws.amazon.com/blogs/aws/aws-online-tech-talks-april-early-may-2018/

We have several upcoming tech talks in the month of April and early May. Come join us to learn about AWS services and solution offerings. We’ll have AWS experts online to help answer questions in real-time. Sign up now to learn more, we look forward to seeing you.

Note – All sessions are free and in Pacific Time.

April & early May — 2018 Schedule

Compute

April 30, 2018 | 01:00 PM – 01:45 PM PTBest Practices for Running Amazon EC2 Spot Instances with Amazon EMR (300) – Learn about the best practices for scaling big data workloads as well as process, store, and analyze big data securely and cost effectively with Amazon EMR and Amazon EC2 Spot Instances.

May 1, 2018 | 01:00 PM – 01:45 PM PTHow to Bring Microsoft Apps to AWS (300) – Learn more about how to save significant money by bringing your Microsoft workloads to AWS.

May 2, 2018 | 01:00 PM – 01:45 PM PTDeep Dive on Amazon EC2 Accelerated Computing (300) – Get a technical deep dive on how AWS’ GPU and FGPA-based compute services can help you to optimize and accelerate your ML/DL and HPC workloads in the cloud.

Containers

April 23, 2018 | 11:00 AM – 11:45 AM PTNew Features for Building Powerful Containerized Microservices on AWS (300) – Learn about how this new feature works and how you can start using it to build and run modern, containerized applications on AWS.

Databases

April 23, 2018 | 01:00 PM – 01:45 PM PTElastiCache: Deep Dive Best Practices and Usage Patterns (200) – Learn about Redis-compatible in-memory data store and cache with Amazon ElastiCache.

April 25, 2018 | 01:00 PM – 01:45 PM PTIntro to Open Source Databases on AWS (200) – Learn how to tap the benefits of open source databases on AWS without the administrative hassle.

DevOps

April 25, 2018 | 09:00 AM – 09:45 AM PTDebug your Container and Serverless Applications with AWS X-Ray in 5 Minutes (300) – Learn how AWS X-Ray makes debugging your Container and Serverless applications fun.

Enterprise & Hybrid

April 23, 2018 | 09:00 AM – 09:45 AM PTAn Overview of Best Practices of Large-Scale Migrations (300) – Learn about the tools and best practices on how to migrate to AWS at scale.

April 24, 2018 | 11:00 AM – 11:45 AM PTDeploy your Desktops and Apps on AWS (300) – Learn how to deploy your desktops and apps on AWS with Amazon WorkSpaces and Amazon AppStream 2.0

IoT

May 2, 2018 | 11:00 AM – 11:45 AM PTHow to Easily and Securely Connect Devices to AWS IoT (200) – Learn how to easily and securely connect devices to the cloud and reliably scale to billions of devices and trillions of messages with AWS IoT.

Machine Learning

April 24, 2018 | 09:00 AM – 09:45 AM PT Automate for Efficiency with Amazon Transcribe and Amazon Translate (200) – Learn how you can increase the efficiency and reach your operations with Amazon Translate and Amazon Transcribe.

April 26, 2018 | 09:00 AM – 09:45 AM PT Perform Machine Learning at the IoT Edge using AWS Greengrass and Amazon Sagemaker (200) – Learn more about developing machine learning applications for the IoT edge.

Mobile

April 30, 2018 | 11:00 AM – 11:45 AM PTOffline GraphQL Apps with AWS AppSync (300) – Come learn how to enable real-time and offline data in your applications with GraphQL using AWS AppSync.

Networking

May 2, 2018 | 09:00 AM – 09:45 AM PT Taking Serverless to the Edge (300) – Learn how to run your code closer to your end users in a serverless fashion. Also, David Von Lehman from Aerobatic will discuss how they used [email protected] to reduce latency and cloud costs for their customer’s websites.

Security, Identity & Compliance

April 30, 2018 | 09:00 AM – 09:45 AM PTAmazon GuardDuty – Let’s Attack My Account! (300) – Amazon GuardDuty Test Drive – Practical steps on generating test findings.

May 3, 2018 | 09:00 AM – 09:45 AM PTProtect Your Game Servers from DDoS Attacks (200) – Learn how to use the new AWS Shield Advanced for EC2 to protect your internet-facing game servers against network layer DDoS attacks and application layer attacks of all kinds.

Serverless

April 24, 2018 | 01:00 PM – 01:45 PM PTTips and Tricks for Building and Deploying Serverless Apps In Minutes (200) – Learn how to build and deploy apps in minutes.

Storage

May 1, 2018 | 11:00 AM – 11:45 AM PTBuilding Data Lakes That Cost Less and Deliver Results Faster (300) – Learn how Amazon S3 Select And Amazon Glacier Select increase application performance by up to 400% and reduce total cost of ownership by extending your data lake into cost-effective archive storage.

May 3, 2018 | 11:00 AM – 11:45 AM PTIntegrating On-Premises Vendors with AWS for Backup (300) – Learn how to work with AWS and technology partners to build backup & restore solutions for your on-premises, hybrid, and cloud native environments.

Using AWS Lambda and Amazon Comprehend for sentiment analysis

Post Syndicated from Chris Munns original https://aws.amazon.com/blogs/compute/using-aws-lambda-and-amazon-comprehend-for-sentiment-analysis/

This post courtesy of Giedrius Praspaliauskas, AWS Solutions Architect

Even with best IVR systems, customers get frustrated. What if you knew that 10 callers in your Amazon Connect contact flow were likely to say “Agent!” in frustration in the next 30 seconds? Would you like to get to them before that happens? What if your bot was smart enough to admit, “I’m sorry this isn’t helping. Let me find someone for you.”?

In this post, I show you how to use AWS Lambda and Amazon Comprehend for sentiment analysis to make your Amazon Lex bots in Amazon Connect more sympathetic.

Setting up a Lambda function for sentiment analysis

There are multiple natural language and text processing frameworks or services available to use with Lambda, including but not limited to Amazon Comprehend, TextBlob, Pattern, and NLTK. Pick one based on the nature of your system:  the type of interaction, languages supported, and so on. For this post, I picked Amazon Comprehend, which uses natural language processing (NLP) to extract insights and relationships in text.

The walkthrough in this post is just an example. In a full-scale implementation, you would likely implement a more nuanced approach. For example, you could keep the overall sentiment score through the conversation and act only when it reaches a certain threshold. It is worth noting that this Lambda function is not called for missed utterances, so there may be a gap between what is being analyzed and what was actually said.

The Lambda function is straightforward. It analyses the input transcript field of the Amazon Lex event. Based on the overall sentiment value, it generates a response message with next step instructions. When the sentiment is neutral, positive, or mixed, the response leaves it to Amazon Lex to decide what the next steps should be. It adds to the response overall sentiment value as an additional session attribute, along with slots’ values received as an input.

When the overall sentiment is negative, the function returns the dialog action, pointing to an escalation intent (specified in the environment variable ESCALATION_INTENT_NAME) or returns the fulfillment closure action with a failure state when the intent is not specified. In addition to actions or intents, the function returns a message, or prompt, to be provided to the customer before taking the next step. Based on the returned action, Amazon Connect can select the appropriate next step in a contact flow.

For this walkthrough, you create a Lambda function using the AWS Management Console:

  1. Open the Lambda console.
  2. Choose Create Function.
  3. Choose Author from scratch (no blueprint).
  4. For Runtime, choose Python 3.6.
  5. For Role, choose Create a custom role. The custom execution role allows the function to detect sentiments, create a log group, stream log events, and store the log events.
  6. Enter the following values:
    • For Role Description, enter Lambda execution role permissions.
    • For IAM Role, choose Create an IAM role.
    • For Role Name, enter LexSentimentAnalysisLambdaRole.
    • For Policy, use the following policy:
{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Action": [
                "logs:CreateLogGroup",
                "logs:CreateLogStream",
                "logs:PutLogEvents"
            ],
            "Resource": "arn:aws:logs:*:*:*"
        },
        {
            "Action": [
                "comprehend:DetectDominantLanguage",
                "comprehend:DetectSentiment"
            ],
            "Effect": "Allow",
            "Resource": "*"
        }
    ]
}
    1. Choose Create function.
    2. Copy/paste the following code to the editor window
import os, boto3

ESCALATION_INTENT_MESSAGE="Seems that you are having troubles with our service. Would you like to be transferred to the associate?"
FULFILMENT_CLOSURE_MESSAGE="Seems that you are having troubles with our service. Let me transfer you to the associate."

escalation_intent_name = os.getenv('ESACALATION_INTENT_NAME', None)

client = boto3.client('comprehend')

def lambda_handler(event, context):
    sentiment=client.detect_sentiment(Text=event['inputTranscript'],LanguageCode='en')['Sentiment']
    if sentiment=='NEGATIVE':
        if escalation_intent_name:
            result = {
                "sessionAttributes": {
                    "sentiment": sentiment
                    },
                    "dialogAction": {
                        "type": "ConfirmIntent", 
                        "message": {
                            "contentType": "PlainText", 
                            "content": ESCALATION_INTENT_MESSAGE
                        }, 
                    "intentName": escalation_intent_name
                    }
            }
        else:
            result = {
                "sessionAttributes": {
                    "sentiment": sentiment
                },
                "dialogAction": {
                    "type": "Close",
                    "fulfillmentState": "Failed",
                    "message": {
                            "contentType": "PlainText",
                            "content": FULFILMENT_CLOSURE_MESSAGE
                    }
                }
            }

    else:
        result ={
            "sessionAttributes": {
                "sentiment": sentiment
            },
            "dialogAction": {
                "type": "Delegate",
                "slots" : event["currentIntent"]["slots"]
            }
        }
    return result
  1. Below the code editor specify the environment variable ESCALATION_INTENT_NAME with a value of Escalate.

  1. Click on Save in the top right of the console.

Now you can test your function.

  1. Click Test at the top of the console.
  2. Configure a new test event using the following test event JSON:
{
  "messageVersion": "1.0",
  "invocationSource": "DialogCodeHook",
  "userId": "1234567890",
  "sessionAttributes": {},
  "bot": {
    "name": "BookSomething",
    "alias": "None",
    "version": "$LATEST"
  },
  "outputDialogMode": "Text",
  "currentIntent": {
    "name": "BookSomething",
    "slots": {
      "slot1": "None",
      "slot2": "None"
    },
    "confirmationStatus": "None"
  },
  "inputTranscript": "I want something"
}
  1. Click Create
  2. Click Test on the console

This message should return a response from Lambda with a sentiment session attribute of NEUTRAL.

However, if you change the input to “This is garbage!”, Lambda changes the dialog action to the escalation intent specified in the environment variable ESCALATION_INTENT_NAME.

Setting up Amazon Lex

Now that you have your Lambda function running, it is time to create the Amazon Lex bot. Use the BookTrip sample bot and call it BookSomething. The IAM role is automatically created on your behalf. Indicate that this bot is not subject to the COPPA, and choose Create. A few minutes later, the bot is ready.

Make the following changes to the default configuration of the bot:

  1. Add an intent with no associated slots. Name it Escalate.
  2. Specify the Lambda function for initialization and validation in the existing two intents (“BookCar” and “BookHotel”), at the same time giving Amazon Lex permission to invoke it.
  3. Leave the other configuration settings as they are and save the intents.

You are ready to build and publish this bot. Set a new alias, BookSomethingWithSentimentAnalysis. When the build finishes, test it.

As you see, sentiment analysis works!

Setting up Amazon Connect

Next, provision an Amazon Connect instance.

After the instance is created, you need to integrate the Amazon Lex bot created in the previous step. For more information, see the Amazon Lex section in the Configuring Your Amazon Connect Instance topic.  You may also want to look at the excellent post by Randall Hunt, New – Amazon Connect and Amazon Lex Integration.

Create a new contact flow, “Sentiment analysis walkthrough”:

  1. Log in into the Amazon Connect instance.
  2. Choose Create contact flow, Create transfer to agent flow.
  3. Add a Get customer input block, open the icon in the top left corner, and specify your Amazon Lex bot and its intents.
  4. Select the Text to speech audio prompt type and enter text for Amazon Connect to play at the beginning of the dialog.
  5. Choose Amazon Lex, enter your Amazon Lex bot name and the alias.
  6. Specify the intents to be used as dialog branches that a customer can choose: BookHotel, BookTrip, or Escalate.
  7. Add two Play prompt blocks and connect them to the customer input block.
    • If booking hotel or car intent is returned from the bot flow, play the corresponding prompt (“OK, will book it for you”) and initiate booking (in this walkthrough, just hang up after the prompt).
    • However, if escalation intent is returned (caused by the sentiment analysis results in the bot), play the prompt (“OK, transferring to an agent”) and initiate the transfer.
  8. Save and publish the contact flow.

As a result, you have a contact flow with a single customer input step and a text-to-speech prompt that uses the Amazon Lex bot. You expect one of the three intents returned:

Edit the phone number to associate the contact flow that you just created. It is now ready for testing. Call the phone number and check how your contact flow works.

Cleanup

Don’t forget to delete all the resources created during this walkthrough to avoid incurring any more costs:

  • Amazon Connect instance
  • Amazon Lex bot
  • Lambda function
  • IAM role LexSentimentAnalysisLambdaRole

Summary

In this walkthrough, you implemented sentiment analysis with a Lambda function. The function can be integrated into Amazon Lex and, as a result, into Amazon Connect. This approach gives you the flexibility to analyze user input and then act. You may find the following potential use cases of this approach to be of interest:

  • Extend the Lambda function to identify “hot” topics in the user input even if the sentiment is not negative and take action proactively. For example, switch to an escalation intent if a user mentioned “where is my order,” which may signal potential frustration.
  • Use Amazon Connect Streams to provide agent sentiment analysis results along with call transfer. Enable service tailored towards particular customer needs and sentiments.
  • Route calls to agents based on both skill set and sentiment.
  • Prioritize calls based on sentiment using multiple Amazon Connect queues instead of transferring directly to an agent.
  • Monitor quality and flag for review contact flows that result in high overall negative sentiment.
  • Implement sentiment and AI/ML based call analysis, such as a real-time recommendation engine. For more details, see Machine Learning on AWS.

If you have questions or suggestions, please comment below.

Backblaze Announces B2 Compute Partnerships

Post Syndicated from Gleb Budman original https://www.backblaze.com/blog/introducing-cloud-compute-services/

Backblaze Announces B2 Compute Partnerships

In 2015, we announced Backblaze B2 Cloud Storage — the most affordable, high performance storage cloud on the planet. The decision to release B2 as a service was in direct response to customers asking us if they could use the same cloud storage infrastructure we use for our Computer Backup service. With B2, we entered a market in direct competition with Amazon S3, Google Cloud Services, and Microsoft Azure Storage. Today, we have over 500 petabytes of data from customers in over 150 countries. At $0.005 / GB / month for storage (1/4th of S3) and $0.01 / GB for downloads (1/5th of S3), it turns out there’s a healthy market for cloud storage that’s easy and affordable.

As B2 has grown, customers wanted to use our cloud storage for a variety of use cases that required not only storage but compute. We’re happy to say that through partnerships with Packet & ServerCentral, today we’re announcing that compute is now available for B2 customers.

Cloud Compute and Storage

Backblaze has directly connected B2 with the compute servers of Packet and ServerCentral, thereby allowing near-instant (< 10 ms) data transfers between services. Also, transferring data between B2 and both our compute partners is free.

  • Storing data in B2 and want to run an AI analysis on it? — There are no fees to move the data to our compute partners.
  • Generating data in an application? — Run the application with one of our partners and store it in B2.
  • Transfers are free and you’ll save more than 50% off of the equivalent set of services from AWS.

These partnerships enable B2 customers to use compute, give our compute partners’ customers access to cloud storage, and introduce new customers to industry-leading storage and compute — all with high-performance, low-latency, and low-cost.

Is This a Big Deal? We Think So

Compute is one of the most requested services from our customers Why? Because it unlocks a number of use cases for them. Let’s look at three popular examples:

Transcoding Media Files

B2 has earned wide adoption in the Media & Entertainment (“M&E”) industry. Our affordable storage and download pricing make B2 great for a wide variety of M&E use cases. But many M&E workflows require compute. Content syndicators, like American Public Television, need the ability to transcode files to meet localization and distribution management requirements.

There are a multitude of reasons that transcode is needed — thumbnail and proxy generation enable M&E professionals to work efficiently. Without compute, the act of transcoding files remains cumbersome. Either the files need to be brought down from the cloud, transcoded, and then pushed back up or they must be kept locally until the project is complete. Both scenarios are inefficient.

Starting today, any content producer can spin up compute with one of our partners, pay by the hour for their transcode processing, and return the new media files to B2 for storage and distribution. The company saves money, moves faster, and ensures their files are safe and secure.

Disaster Recovery

Backblaze’s heritage is based on providing outstanding backup services. When you have incredibly affordable cloud storage, it ends up being a great destination for your backup data.

Most enterprises have virtual machines (“VMs”) running in their infrastructure and those VMs need to be backed up. In a disaster scenario, a business wants to know they can get back up and running quickly.

With all data stored in B2, a business can get up and running quickly. Simply restore your backed up VM to one of our compute providers, and your business will be able to get back online.

Since B2 does not place restrictions, delays, or penalties on getting data out, customers can get back up and running quickly and affordably.

Saving $74 Million (aka “The Dropbox Effect”)

Ten years ago, Backblaze decided that S3 was too costly a platform to build its cloud storage business. Instead, we created the Backblaze Storage Pod and our own cloud storage infrastructure. That decision enabled us to offer our customers storage at a previously unavailable price point and maintain those prices for over a decade. It also laid the foundation for Netflix Open Connect and Facebook Open Compute.

Dropbox recently migrated the majority of their cloud services off of AWS and onto Dropbox’s own infrastructure. By leaving AWS, Dropbox was able to build out their own data centers and still save over $74 Million. They achieved those savings by avoiding the fees AWS charges for storing and downloading data, which, incidentally, are five times higher than Backblaze B2.

For Dropbox, being able to realize savings was possible because they have access to enough capital and expertise that they can build out their own infrastructure. For companies that have such resources and scale, that’s a great answer.

“Before this offering, the economics of the cloud would have made our business simply unviable.” — Gabriel Menegatti, SlicingDice

The questions Backblaze and our compute partners pondered was “how can we democratize the Dropbox effect for our storage and compute customers? How can we help customers do more and pay less?” The answer we came up with was to connect Backblaze’s B2 storage with strategic compute partners and remove any transfer fees between them. You may not save $74 million as Dropbox did, but you can choose the optimal providers for your use case and realize significant savings in the process.

This Sounds Good — Tell Me More About Your Partners

We’re very fortunate to be launching our compute program with two fantastic partners in Packet and ServerCentral. These partners allow us to offer a range of computing services.

Packet

We recommend Packet for customers that need on-demand, high performance, bare metal servers available by the hour. They also have robust offerings for private / customized deployments. Their offerings end up costing 50-75% of the equivalent offerings from EC2.

To get started with Packet and B2, visit our partner page on Packet.net.

ServerCentral

ServerCentral is the right partner for customers that have business and IT challenges that require more than “just” hardware. They specialize in fully managed, custom cloud solutions that solve complex business and IT challenges. ServerCentral also has expertise in managed network solutions to address global connectivity and content delivery.

To get started with ServerCentral and B2, visit our partner page on ServerCentral.com.

What’s Next?

We’re excited to find out. The combination of B2 and compute unlocks use cases that were previously impossible or at least unaffordable.

“The combination of performance and price offered by this partnership enables me to create an entirely new business line. Before this offering, the economics of the cloud would have made our business simply unviable,” noted Gabriel Menegatti, co-founder at SlicingDice, a serverless data warehousing service. “Knowing that transfers between compute and B2 are free means I don’t have to worry about my business being successful. And, with download pricing from B2 at just $0.01 GB, I know I’m avoiding a 400% tax from AWS on data I retrieve.”

What can you do with B2 & compute? Please share your ideas with us in the comments. And, for those attending NAB 2018 in Las Vegas next week, please come by and say hello!

The post Backblaze Announces B2 Compute Partnerships appeared first on Backblaze Blog | Cloud Storage & Cloud Backup.

Node.js 8.10 runtime now available in AWS Lambda

Post Syndicated from Chris Munns original https://aws.amazon.com/blogs/compute/node-js-8-10-runtime-now-available-in-aws-lambda/

This post courtesy of Ed Lima, AWS Solutions Architect

We are excited to announce that you can now develop your AWS Lambda functions using the Node.js 8.10 runtime, which is the current Long Term Support (LTS) version of Node.js. Start using this new version today by specifying a runtime parameter value of nodejs8.10 when creating or updating functions.

Supporting async/await

The Lambda programming model for Node.js 8.10 now supports defining a function handler using the async/await pattern.

Asynchronous or non-blocking calls are an inherent and important part of applications, as user and human interfaces are asynchronous by nature. If you decide to have a coffee with a friend, you usually order the coffee then start or continue a conversation with your friend while the coffee is getting ready. You don’t wait for the coffee to be ready before you start talking. These activities are asynchronous, because you can start one and then move to the next without waiting for completion. Otherwise, you’d delay (or block) the start of the next activity.

Asynchronous calls used to be handled in Node.js using callbacks. That presented problems when they were nested within other callbacks in multiple levels, making the code difficult to maintain and understand.

Promises were implemented to try to solve issues caused by “callback hell.” They allow asynchronous operations to call their own methods and handle what happens when a call is successful or when it fails. As your requirements become more complicated, even promises become harder to work with and may still end up complicating your code.

Async/await is the new way of handling asynchronous operations in Node.js, and makes for simpler, easier, and cleaner code for non-blocking calls. It still uses promises but a callback is returned directly from the asynchronous function, just as if it were a synchronous blocking function.

Take for instance the following Lambda function to get the current account settings, using the Node.js 6.10 runtime:

let AWS = require('aws-sdk');
let lambda = new AWS.Lambda();

exports.handler = (event, context, callback) => {
    let getAccountSettingsPromise = lambda.getAccountSettings().promise();
    getAccountSettingsPromise.then(
        (data) => {
            callback(null, data);
        },
        (err) => {
            console.log(err);
            callback(err);
        }
    );
};

With the new Node.js 8.10 runtime, there are new handler types that can be declared with the “async” keyword or can return a promise directly.

This is how the same function looks like using async/await with Node.js 8.10:

let AWS = require('aws-sdk');
let lambda = new AWS.Lambda();

exports.handler = async (event) => {
    return await lambda.getAccountSettings().promise() ;
};

Alternatively, you could have the handler return a promise directly:

let AWS = require('aws-sdk');
let lambda = new AWS.Lambda();

exports.handler = (event) => {
    return new Promise((resolve, reject) => {
        lambda.getAccountSettings(event)
        .then((data) => {
            resolve data;
        })
        .catch(reject);
     });
};

The new handler types are alternatives to the callback pattern, which is still fully supported.

All three functions return the same results. However, in the new runtime with async/await, all callbacks in the code are gone, which makes it easier to read. This is especially true for those less familiar with promises.

{
    "AccountLimit":{
        "TotalCodeSize":80530636800,
        "CodeSizeUnzipped":262144000,
        "CodeSizeZipped":52428800, 
        "ConcurrentExecutions":1000,
        "UnreservedConcurrentExecutions":1000
    },
    "AccountUsage":{
        "TotalCodeSize":52234461,
        "FunctionCount":53
    }
}

Another great advantage of async/await is better error handling. You can use a try/catch block inside the scope of an async function. Even though the function awaits an asynchronous operation, any errors end up in the catch block.

You can improve your previous Node.js 8.10 function with this trusted try/catch error handling pattern:

let AWS = require('aws-sdk');
let lambda = new AWS.Lambda();
let data;

exports.handler = async (event) => {
    try {
        data = await lambda.getAccountSettings().promise();
    }
    catch (err) {
        console.log(err);
        return err;
    }
    return data;
};

While you now have a similar number of lines in both runtimes, the code is cleaner and more readable with async/await. It makes the asynchronous calls look more synchronous. However, it is important to notice that the code is still executed the same way as if it were using a callback or promise-based API.

Backward compatibility

You may port your existing Node.js 4.3 and 6.10 functions over to Node.js 8.10 by updating the runtime. Node.js 8.10 does include numerous breaking changes from previous Node versions.

Make sure to review the API changes between Node.js 4.3, 6.10, and Node.js 8.10 to see if there are other changes that might affect your code. We recommend testing that your Lambda function passes internal validation for its behavior when upgrading to the new runtime version.

You can use Lambda versions/aliases to safely test that your function runs as expected on Node 8.10, before routing production traffic to it.

New node features

You can now get better performance when compared to the previous LTS version 6.x (up to 20%). The new V8 6.0 engine comes with Turbofan and the Ignition pipeline, which leads to lower memory consumption and faster startup time across Node.js applications.

HTTP/2, which is subject to future changes, allows developers to use the new protocol to speed application development and undo many of HTTP/1.1 workarounds to make applications faster, simpler, and more powerful.

For more information, see the AWS Lambda Developer Guide.

Hope you enjoy and… go build with Node.js 8.10!

Innovation Flywheels and the AWS Serverless Application Repository

Post Syndicated from Tim Wagner original https://aws.amazon.com/blogs/compute/innovation-flywheels-and-the-aws-serverless-application-repository/

At AWS, our customers have always been the motivation for our innovation. In turn, we’re committed to helping them accelerate the pace of their own innovation. It was in the spirit of helping our customers achieve their objectives faster that we launched AWS Lambda in 2014, eliminating the burden of server management and enabling AWS developers to focus on business logic instead of the challenges of provisioning and managing infrastructure.

 

In the years since, our customers have built amazing things using Lambda and other serverless offerings, such as Amazon API Gateway, Amazon Cognito, and Amazon DynamoDB. Together, these services make it easy to build entire applications without the need to provision, manage, monitor, or patch servers. By removing much of the operational drudgery of infrastructure management, we’ve helped our customers become more agile and achieve faster time-to-market for their applications and services. By eliminating cold servers and cold containers with request-based pricing, we’ve also eliminated the high cost of idle capacity and helped our customers achieve dramatically higher utilization and better economics.

After we launched Lambda, though, we quickly learned an important lesson: A single Lambda function rarely exists in isolation. Rather, many functions are part of serverless applications that collectively deliver customer value. Whether it’s the combination of event sources and event handlers, as serverless web apps that combine APIs with functions for dynamic content with static content repositories, or collections of functions that together provide a microservice architecture, our customers were building and delivering serverless architectures for every conceivable problem. Despite the economic and agility benefits that hundreds of thousands of AWS customers were enjoying with Lambda, we realized there was still more we could do.

How Customer Feedback Inspired Us to Innovate

We heard from our customers that getting started—either from scratch or when augmenting their implementation with new techniques or technologies—remained a challenge. When we looked for serverless assets to share, we found stellar examples built by serverless pioneers that represented a multitude of solutions across industries.

There were apps to facilitate monitoring and logging, to process image and audio files, to create Alexa skills, and to integrate with notification and location services. These apps ranged from “getting started” examples to complete, ready-to-run assets. What was missing, however, was a unified place for customers to discover this diversity of serverless applications and a step-by-step interface to help them configure and deploy them.

We also heard from customers and partners that building their own ecosystems—ecosystems increasingly composed of functions, APIs, and serverless applications—remained a challenge. They wanted a simple way to share samples, create extensibility, and grow consumer relationships on top of serverless approaches.

 

We built the AWS Serverless Application Repository to help solve both of these challenges by offering publishers and consumers of serverless apps a simple, fast, and effective way to share applications and grow user communities around them. Now, developers can easily learn how to apply serverless approaches to their implementation and business challenges by discovering, customizing, and deploying serverless applications directly from the Serverless Application Repository. They can also find libraries, components, patterns, and best practices that augment their existing knowledge, helping them bring services and applications to market faster than ever before.

How the AWS Serverless Application Repository Inspires Innovation for All Customers

Companies that want to create ecosystems, share samples, deliver extensibility and customization options, and complement their existing SaaS services use the Serverless Application Repository as a distribution channel, producing apps that can be easily discovered and consumed by their customers. AWS partners like HERE have introduced their location and transit services to thousands of companies and developers. Partners like Datadog, Splunk, and TensorIoT have showcased monitoring, logging, and IoT applications to the serverless community.

Individual developers are also publishing serverless applications that push the boundaries of innovation—some have published applications that leverage machine learning to predict the quality of wine while others have published applications that monitor crypto-currencies, instantly build beautiful image galleries, or create fast and simple surveys. All of these publishers are using serverless apps, and the Serverless Application Repository, as the easiest way to share what they’ve built. Best of all, their customers and fellow community members can find and deploy these applications with just a few clicks in the Lambda console. Apps in the Serverless Application Repository are free of charge, making it easy to explore new solutions or learn new technologies.

Finally, we at AWS continue to publish apps for the community to use. From apps that leverage Amazon Cognito to sync user data across applications to our latest collection of serverless apps that enable users to quickly execute common financial calculations, we’re constantly looking for opportunities to contribute to community growth and innovation.

At AWS, we’re more excited than ever by the growing adoption of serverless architectures and the innovation that services like AWS Lambda make possible. Helping our customers create and deliver new ideas drives us to keep inventing ways to make building and sharing serverless apps even easier. As the number of applications in the Serverless Application Repository grows, so too will the innovation that it fuels for both the owners and the consumers of those apps. With the general availability of the Serverless Application Repository, our customers become more than the engine of our innovation—they become the engine of innovation for one another.

To browse, discover, deploy, and publish serverless apps in minutes, visit the Serverless Application Repository. Go serverless—and go innovate!

Dr. Tim Wagner is the General Manager of AWS Lambda and Amazon API Gateway.

Performing Unit Testing in an AWS CodeStar Project

Post Syndicated from Jerry Mathen Jacob original https://aws.amazon.com/blogs/devops/performing-unit-testing-in-an-aws-codestar-project/

In this blog post, I will show how you can perform unit testing as a part of your AWS CodeStar project. AWS CodeStar helps you quickly develop, build, and deploy applications on AWS. With AWS CodeStar, you can set up your continuous delivery (CD) toolchain and manage your software development from one place.

Because unit testing tests individual units of application code, it is helpful for quickly identifying and isolating issues. As a part of an automated CI/CD process, it can also be used to prevent bad code from being deployed into production.

Many of the AWS CodeStar project templates come preconfigured with a unit testing framework so that you can start deploying your code with more confidence. The unit testing is configured to run in the provided build stage so that, if the unit tests do not pass, the code is not deployed. For a list of AWS CodeStar project templates that include unit testing, see AWS CodeStar Project Templates in the AWS CodeStar User Guide.

The scenario

As a big fan of superhero movies, I decided to list my favorites and ask my friends to vote on theirs by using a WebService endpoint I created. The example I use is a Python web service running on AWS Lambda with AWS CodeCommit as the code repository. CodeCommit is a fully managed source control system that hosts Git repositories and works with all Git-based tools.

Here’s how you can create the WebService endpoint:

Sign in to the AWS CodeStar console. Choose Start a project, which will take you to the list of project templates.

create project

For code edits I will choose AWS Cloud9, which is a cloud-based integrated development environment (IDE) that you use to write, run, and debug code.

choose cloud9

Here are the other tasks required by my scenario:

  • Create a database table where the votes can be stored and retrieved as needed.
  • Update the logic in the Lambda function that was created for posting and getting the votes.
  • Update the unit tests (of course!) to verify that the logic works as expected.

For a database table, I’ve chosen Amazon DynamoDB, which offers a fast and flexible NoSQL database.

Getting set up on AWS Cloud9

From the AWS CodeStar console, go to the AWS Cloud9 console, which should take you to your project code. I will open up a terminal at the top-level folder under which I will set up my environment and required libraries.

Use the following command to set the PYTHONPATH environment variable on the terminal.

export PYTHONPATH=/home/ec2-user/environment/vote-your-movie

You should now be able to use the following command to execute the unit tests in your project.

python -m unittest discover vote-your-movie/tests

cloud9 setup

Start coding

Now that you have set up your local environment and have a copy of your code, add a DynamoDB table to the project by defining it through a template file. Open template.yml, which is the Serverless Application Model (SAM) template file. This template extends AWS CloudFormation to provide a simplified way of defining the Amazon API Gateway APIs, AWS Lambda functions, and Amazon DynamoDB tables required by your serverless application.

AWSTemplateFormatVersion: 2010-09-09
Transform:
- AWS::Serverless-2016-10-31
- AWS::CodeStar

Parameters:
  ProjectId:
    Type: String
    Description: CodeStar projectId used to associate new resources to team members

Resources:
  # The DB table to store the votes.
  MovieVoteTable:
    Type: AWS::Serverless::SimpleTable
    Properties:
      PrimaryKey:
        # Name of the "Candidate" is the partition key of the table.
        Name: Candidate
        Type: String
  # Creating a new lambda function for retrieving and storing votes.
  MovieVoteLambda:
    Type: AWS::Serverless::Function
    Properties:
      Handler: index.handler
      Runtime: python3.6
      Environment:
        # Setting environment variables for your lambda function.
        Variables:
          TABLE_NAME: !Ref "MovieVoteTable"
          TABLE_REGION: !Ref "AWS::Region"
      Role:
        Fn::ImportValue:
          !Join ['-', [!Ref 'ProjectId', !Ref 'AWS::Region', 'LambdaTrustRole']]
      Events:
        GetEvent:
          Type: Api
          Properties:
            Path: /
            Method: get
        PostEvent:
          Type: Api
          Properties:
            Path: /
            Method: post

We’ll use Python’s boto3 library to connect to AWS services. And we’ll use Python’s mock library to mock AWS service calls for our unit tests.
Use the following command to install these libraries:

pip install --upgrade boto3 mock -t .

install dependencies

Add these libraries to the buildspec.yml, which is the YAML file that is required for CodeBuild to execute.

version: 0.2

phases:
  install:
    commands:

      # Upgrade AWS CLI to the latest version
      - pip install --upgrade awscli boto3 mock

  pre_build:
    commands:

      # Discover and run unit tests in the 'tests' directory. For more information, see <https://docs.python.org/3/library/unittest.html#test-discovery>
      - python -m unittest discover tests

  build:
    commands:

      # Use AWS SAM to package the application by using AWS CloudFormation
      - aws cloudformation package --template template.yml --s3-bucket $S3_BUCKET --output-template template-export.yml

artifacts:
  type: zip
  files:
    - template-export.yml

Open the index.py where we can write the simple voting logic for our Lambda function.

import json
import datetime
import boto3
import os

table_name = os.environ['TABLE_NAME']
table_region = os.environ['TABLE_REGION']

VOTES_TABLE = boto3.resource('dynamodb', region_name=table_region).Table(table_name)
CANDIDATES = {"A": "Black Panther", "B": "Captain America: Civil War", "C": "Guardians of the Galaxy", "D": "Thor: Ragnarok"}

def handler(event, context):
    if event['httpMethod'] == 'GET':
        resp = VOTES_TABLE.scan()
        return {'statusCode': 200,
                'body': json.dumps({item['Candidate']: int(item['Votes']) for item in resp['Items']}),
                'headers': {'Content-Type': 'application/json'}}

    elif event['httpMethod'] == 'POST':
        try:
            body = json.loads(event['body'])
        except:
            return {'statusCode': 400,
                    'body': 'Invalid input! Expecting a JSON.',
                    'headers': {'Content-Type': 'application/json'}}
        if 'candidate' not in body:
            return {'statusCode': 400,
                    'body': 'Missing "candidate" in request.',
                    'headers': {'Content-Type': 'application/json'}}
        if body['candidate'] not in CANDIDATES.keys():
            return {'statusCode': 400,
                    'body': 'You must vote for one of the following candidates - {}.'.format(get_allowed_candidates()),
                    'headers': {'Content-Type': 'application/json'}}

        resp = VOTES_TABLE.update_item(
            Key={'Candidate': CANDIDATES.get(body['candidate'])},
            UpdateExpression='ADD Votes :incr',
            ExpressionAttributeValues={':incr': 1},
            ReturnValues='ALL_NEW'
        )
        return {'statusCode': 200,
                'body': "{} now has {} votes".format(CANDIDATES.get(body['candidate']), resp['Attributes']['Votes']),
                'headers': {'Content-Type': 'application/json'}}

def get_allowed_candidates():
    l = []
    for key in CANDIDATES:
        l.append("'{}' for '{}'".format(key, CANDIDATES.get(key)))
    return ", ".join(l)

What our code basically does is take in the HTTPS request call as an event. If it is an HTTP GET request, it gets the votes result from the table. If it is an HTTP POST request, it sets a vote for the candidate of choice. We also validate the inputs in the POST request to filter out requests that seem malicious. That way, only valid calls are stored in the table.

In the example code provided, we use a CANDIDATES variable to store our candidates, but you can store the candidates in a JSON file and use Python’s json library instead.

Let’s update the tests now. Under the tests folder, open the test_handler.py and modify it to verify the logic.

import os
# Some mock environment variables that would be used by the mock for DynamoDB
os.environ['TABLE_NAME'] = "MockHelloWorldTable"
os.environ['TABLE_REGION'] = "us-east-1"

# The library containing our logic.
import index

# Boto3's core library
import botocore
# For handling JSON.
import json
# Unit test library
import unittest
## Getting StringIO based on your setup.
try:
    from StringIO import StringIO
except ImportError:
    from io import StringIO
## Python mock library
from mock import patch, call
from decimal import Decimal

@patch('botocore.client.BaseClient._make_api_call')
class TestCandidateVotes(unittest.TestCase):

    ## Test the HTTP GET request flow. 
    ## We expect to get back a successful response with results of votes from the table (mocked).
    def test_get_votes(self, boto_mock):
        # Input event to our method to test.
        expected_event = {'httpMethod': 'GET'}
        # The mocked values in our DynamoDB table.
        items_in_db = [{'Candidate': 'Black Panther', 'Votes': Decimal('3')},
                        {'Candidate': 'Captain America: Civil War', 'Votes': Decimal('8')},
                        {'Candidate': 'Guardians of the Galaxy', 'Votes': Decimal('8')},
                        {'Candidate': "Thor: Ragnarok", 'Votes': Decimal('1')}
                    ]
        # The mocked DynamoDB response.
        expected_ddb_response = {'Items': items_in_db}
        # The mocked response we expect back by calling DynamoDB through boto.
        response_body = botocore.response.StreamingBody(StringIO(str(expected_ddb_response)),
                                                        len(str(expected_ddb_response)))
        # Setting the expected value in the mock.
        boto_mock.side_effect = [expected_ddb_response]
        # Expecting that there would be a call to DynamoDB Scan function during execution with these parameters.
        expected_calls = [call('Scan', {'TableName': os.environ['TABLE_NAME']})]

        # Call the function to test.
        result = index.handler(expected_event, {})

        # Run unit test assertions to verify the expected calls to mock have occurred and verify the response.
        assert result.get('headers').get('Content-Type') == 'application/json'
        assert result.get('statusCode') == 200

        result_body = json.loads(result.get('body'))
        # Verifying that the results match to that from the table.
        assert len(result_body) == len(items_in_db)
        for i in range(len(result_body)):
            assert result_body.get(items_in_db[i].get("Candidate")) == int(items_in_db[i].get("Votes"))

        assert boto_mock.call_count == 1
        boto_mock.assert_has_calls(expected_calls)

    ## Test the HTTP POST request flow that places a vote for a selected candidate.
    ## We expect to get back a successful response with a confirmation message.
    def test_place_valid_candidate_vote(self, boto_mock):
        # Input event to our method to test.
        expected_event = {'httpMethod': 'POST', 'body': "{\"candidate\": \"D\"}"}
        # The mocked response in our DynamoDB table.
        expected_ddb_response = {'Attributes': {'Candidate': "Thor: Ragnarok", 'Votes': Decimal('2')}}
        # The mocked response we expect back by calling DynamoDB through boto.
        response_body = botocore.response.StreamingBody(StringIO(str(expected_ddb_response)),
                                                        len(str(expected_ddb_response)))
        # Setting the expected value in the mock.
        boto_mock.side_effect = [expected_ddb_response]
        # Expecting that there would be a call to DynamoDB UpdateItem function during execution with these parameters.
        expected_calls = [call('UpdateItem', {
                                                'TableName': os.environ['TABLE_NAME'], 
                                                'Key': {'Candidate': 'Thor: Ragnarok'},
                                                'UpdateExpression': 'ADD Votes :incr',
                                                'ExpressionAttributeValues': {':incr': 1},
                                                'ReturnValues': 'ALL_NEW'
                                            })]
        # Call the function to test.
        result = index.handler(expected_event, {})
        # Run unit test assertions to verify the expected calls to mock have occurred and verify the response.
        assert result.get('headers').get('Content-Type') == 'application/json'
        assert result.get('statusCode') == 200

        assert result.get('body') == "{} now has {} votes".format(
            expected_ddb_response['Attributes']['Candidate'], 
            expected_ddb_response['Attributes']['Votes'])

        assert boto_mock.call_count == 1
        boto_mock.assert_has_calls(expected_calls)

    ## Test the HTTP POST request flow that places a vote for an non-existant candidate.
    ## We expect to get back a successful response with a confirmation message.
    def test_place_invalid_candidate_vote(self, boto_mock):
        # Input event to our method to test.
        # The valid IDs for the candidates are A, B, C, and D
        expected_event = {'httpMethod': 'POST', 'body': "{\"candidate\": \"E\"}"}
        # Call the function to test.
        result = index.handler(expected_event, {})
        # Run unit test assertions to verify the expected calls to mock have occurred and verify the response.
        assert result.get('headers').get('Content-Type') == 'application/json'
        assert result.get('statusCode') == 400
        assert result.get('body') == 'You must vote for one of the following candidates - {}.'.format(index.get_allowed_candidates())

    ## Test the HTTP POST request flow that places a vote for a selected candidate but associated with an invalid key in the POST body.
    ## We expect to get back a failed (400) response with an appropriate error message.
    def test_place_invalid_data_vote(self, boto_mock):
        # Input event to our method to test.
        # "name" is not the expected input key.
        expected_event = {'httpMethod': 'POST', 'body': "{\"name\": \"D\"}"}
        # Call the function to test.
        result = index.handler(expected_event, {})
        # Run unit test assertions to verify the expected calls to mock have occurred and verify the response.
        assert result.get('headers').get('Content-Type') == 'application/json'
        assert result.get('statusCode') == 400
        assert result.get('body') == 'Missing "candidate" in request.'

    ## Test the HTTP POST request flow that places a vote for a selected candidate but not as a JSON string which the body of the request expects.
    ## We expect to get back a failed (400) response with an appropriate error message.
    def test_place_malformed_json_vote(self, boto_mock):
        # Input event to our method to test.
        # "body" receives a string rather than a JSON string.
        expected_event = {'httpMethod': 'POST', 'body': "Thor: Ragnarok"}
        # Call the function to test.
        result = index.handler(expected_event, {})
        # Run unit test assertions to verify the expected calls to mock have occurred and verify the response.
        assert result.get('headers').get('Content-Type') == 'application/json'
        assert result.get('statusCode') == 400
        assert result.get('body') == 'Invalid input! Expecting a JSON.'

if __name__ == '__main__':
    unittest.main()

I am keeping the code samples well commented so that it’s clear what each unit test accomplishes. It tests the success conditions and the failure paths that are handled in the logic.

In my unit tests I use the patch decorator (@patch) in the mock library. @patch helps mock the function you want to call (in this case, the botocore library’s _make_api_call function in the BaseClient class).
Before we commit our changes, let’s run the tests locally. On the terminal, run the tests again. If all the unit tests pass, you should expect to see a result like this:

You:~/environment $ python -m unittest discover vote-your-movie/tests
.....
----------------------------------------------------------------------
Ran 5 tests in 0.003s

OK
You:~/environment $

Upload to AWS

Now that the tests have passed, it’s time to commit and push the code to source repository!

Add your changes

From the terminal, go to the project’s folder and use the following command to verify the changes you are about to push.

git status

To add the modified files only, use the following command:

git add -u

Commit your changes

To commit the changes (with a message), use the following command:

git commit -m "Logic and tests for the voting webservice."

Push your changes to AWS CodeCommit

To push your committed changes to CodeCommit, use the following command:

git push

In the AWS CodeStar console, you can see your changes flowing through the pipeline and being deployed. There are also links in the AWS CodeStar console that take you to this project’s build runs so you can see your tests running on AWS CodeBuild. The latest link under the Build Runs table takes you to the logs.

unit tests at codebuild

After the deployment is complete, AWS CodeStar should now display the AWS Lambda function and DynamoDB table created and synced with this project. The Project link in the AWS CodeStar project’s navigation bar displays the AWS resources linked to this project.

codestar resources

Because this is a new database table, there should be no data in it. So, let’s put in some votes. You can download Postman to test your application endpoint for POST and GET calls. The endpoint you want to test is the URL displayed under Application endpoints in the AWS CodeStar console.

Now let’s open Postman and look at the results. Let’s create some votes through POST requests. Based on this example, a valid vote has a value of A, B, C, or D.
Here’s what a successful POST request looks like:

POST success

Here’s what it looks like if I use some value other than A, B, C, or D:

 

POST Fail

Now I am going to use a GET request to fetch the results of the votes from the database.

GET success

And that’s it! You have now created a simple voting web service using AWS Lambda, Amazon API Gateway, and DynamoDB and used unit tests to verify your logic so that you ship good code.
Happy coding!

Our Newest AWS Community Heroes (Spring 2018 Edition)

Post Syndicated from Betsy Chernoff original https://aws.amazon.com/blogs/aws/our-newest-aws-community-heroes-spring-2018-edition/

The AWS Community Heroes program helps shine a spotlight on some of the innovative work being done by rockstar AWS developers around the globe. Marrying cloud expertise with a passion for community building and education, these Heroes share their time and knowledge across social media and in-person events. Heroes also actively help drive content at Meetups, workshops, and conferences.

This March, we have five Heroes that we’re happy to welcome to our network of cloud innovators:

Peter Sbarski

Peter Sbarski is VP of Engineering at A Cloud Guru and the organizer of Serverlessconf, the world’s first conference dedicated entirely to serverless architectures and technologies. His work at A Cloud Guru allows him to work with, talk and write about serverless architectures, cloud computing, and AWS. He has written a book called Serverless Architectures on AWS and is currently collaborating on another book called Serverless Design Patterns with Tim Wagner and Yochay Kiriaty.

Peter is always happy to talk about cloud computing and AWS, and can be found at conferences and meetups throughout the year. He helps to organize Serverless Meetups in Melbourne and Sydney in Australia, and is always keen to share his experience working on interesting and innovative cloud projects.

Peter’s passions include serverless technologies, event-driven programming, back end architecture, microservices, and orchestration of systems. Peter holds a PhD in Computer Science from Monash University, Australia and can be followed on Twitter, LinkedIn, Medium, and GitHub.

 

 

 

Michael Wittig

Michael Wittig is co-founder of widdix, a consulting company focused on cloud architecture, DevOps, and software development on AWS. widdix maintains several AWS related open source projects, most notably a collection of production-ready CloudFormation templates. In 2016, widdix released marbot: a Slack bot supporting your DevOps team to detect and solve incidents on AWS.

In close collaboration with his brother Andreas Wittig, the Wittig brothers are actively creating AWS related content. Their book Amazon Web Services in Action (Manning) introduces AWS with a strong focus on automation. Andreas and Michael run the blog cloudonaut.io where they share their knowledge about AWS with the community. The Wittig brothers also published a bunch of video courses with O’Reilly, Manning, Pluralsight, and A Cloud Guru. You can also find them speaking at conferences and user groups in Europe. Both brothers are co-organizing the AWS user group in Stuttgart.

 

 

 

 

Fernando Hönig

Fernando is an experienced Infrastructure Solutions Leader, holding 5 AWS Certifications, with extensive IT Architecture and Management experience in a variety of market sectors. Working as a Cloud Architect Consultant in United Kingdom since 2014, Fernando built an online community for Hispanic speakers worldwide.

Fernando founded a LinkedIn Group, a Slack Community and a YouTube channel all of them named “AWS en Español”, and started to run a monthly webinar via YouTube streaming where different leaders discuss aspects and challenges around AWS Cloud.

During the last 18 months he’s been helping to run and coach AWS User Group leaders across LATAM and Spain, and 10 new User Groups were founded during this time.

Feel free to follow Fernando on Twitter, connect with him on LinkedIn, or join the ever-growing Hispanic Community via Slack, LinkedIn or YouTube.

 

 

 

Anders Bjørnestad

Anders is a consultant and cloud evangelist at Webstep AS in Norway. He finished his degree in Computer Science at the Norwegian Institute of Technology at about the same time the Internet emerged as a public service. Since then he has been an IT consultant and a passionate advocate of knowledge-sharing.

He architected and implemented his first customer solution on AWS back in 2010, and is essential in building Webstep’s core cloud team. Anders applies his broad expert knowledge across all layers of the organizational stack. He engages with developers on technology and architectures and with top management where he advises about cloud strategies and new business models.

Anders enjoys helping people increase their understanding of AWS and cloud in general, and holds several AWS certifications. He co-founded and co-organizes the AWS User Groups in the largest cities in Norway (Oslo, Bergen, Trondheim and Stavanger), and also uses any opportunity to engage in events related to AWS and cloud wherever he is.

You can follow him on Twitter or connect with him on LinkedIn.

To learn more about the AWS Community Heroes Program and how to get involved with your local AWS community, click here.

 

 

 

 

 

 

 

 

Serverless Dynamic Web Pages in AWS: Provisioned with CloudFormation

Post Syndicated from AWS Admin original https://aws.amazon.com/blogs/architecture/serverless-dynamic-web-pages-in-aws-provisioned-with-cloudformation/

***This blog is authored by Mike Okner of Monsanto, an AWS customer. It originally appeared on the Monsanto company blog. Minor edits were made to the original post.***

Recently, I was looking to create a status page app to monitor a few important internal services. I wanted this app to be as lightweight, reliable, and hassle-free as possible, so using a “serverless” architecture that doesn’t require any patching or other maintenance was quite appealing.

I also don’t deploy anything in a production AWS environment outside of some sort of template (usually CloudFormation) as a rule. I don’t want to have to come back to something I created ad hoc in the console after 6 months and try to recall exactly how I architected all of the resources. I’ll inevitably forget something and create more problems before solving the original one. So building the status page in a template was a requirement.

The Design
I settled on a design using two Lambda functions, both written in Python 3.6.

The first Lambda function makes requests out to a list of important services and writes their current status to a DynamoDB table. This function is executed once per minute via CloudWatch Event Rule.

The second Lambda function reads each service’s status & uptime information from DynamoDB and renders a Jinja template. This function is behind an API Gateway that has been configured to return text/html instead of its default application/json Content-Type.

The CloudFormation Template
AWS provides a Serverless Application Model template transformer to streamline the templating of Lambda + API Gateway designs, but it assumes (like everything else about the API Gateway) that you’re actually serving an API that returns JSON content. So, unfortunately, it won’t work for this use-case because we want to return HTML content. Instead, we’ll have to enumerate every resource like usual.

The Skeleton
We’ll be using YAML for the template in this example. I find it easier to read than JSON, but you can easily convert between the two with a converter if you disagree.

---
AWSTemplateFormatVersion: '2010-09-09'
Description: Serverless status page app
Resources:
  # [...Resources]

The Status-Checker Lambda Resource
This one is triggered on a schedule by CloudWatch, and looks like:

# Status Checker Lambda
CheckerLambda:
  Type: AWS::Lambda::Function
  Properties:
    Code: ./lambda.zip
    Environment:
      Variables:
        TABLE_NAME: !Ref DynamoTable
    Handler: checker.handler
    Role:
      Fn::GetAtt:
      - CheckerLambdaRole
      - Arn
    Runtime: python3.6
    Timeout: 45
CheckerLambdaRole:
  Type: AWS::IAM::Role
  Properties:
    ManagedPolicyArns:
    - arn:aws:iam::aws:policy/AmazonDynamoDBFullAccess
    - arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole
    AssumeRolePolicyDocument:
      Version: '2012-10-17'
      Statement:
      - Action:
        - sts:AssumeRole
        Effect: Allow
        Principal:
          Service:
          - lambda.amazonaws.com
CheckerLambdaTimer:
  Type: AWS::Events::Rule
  Properties:
    ScheduleExpression: rate(1 minute)
    Targets:
    - Id: CheckerLambdaTimerLambdaTarget
      Arn:
        Fn::GetAtt:
        - CheckerLambda
        - Arn
CheckerLambdaTimerPermission:
  Type: AWS::Lambda::Permission
  Properties:
    Action: lambda:invokeFunction
    FunctionName: !Ref CheckerLambda
    SourceArn:
      Fn::GetAtt:
      - CheckerLambdaTimer
      - Arn
    Principal: events.amazonaws.com

Let’s break that down a bit.

The CheckerLambda is the actual Lambda function. The Code section is a local path to a ZIP file containing the code and its dependencies. I’m using CloudFormation’s packaging feature to automatically push the deployable to S3.

The CheckerLambdaRole is the IAM role the Lambda will assume which grants it access to DynamoDB in addition to the usual Lambda logging permissions.

The CheckerLambdaTimer is the CloudWatch Events Rule that triggers the checker to run once per minute.

The CheckerLambdaTimerPermission grants CloudWatch the ability to invoke the checker Lambda function on its interval.

The Web Page Gateway
The API Gateway handles incoming requests for the web page, invokes the Lambda, and then returns the Lambda’s results as HTML content. Its template looks like:

# API Gateway for Web Page Lambda
PageGateway:
  Type: AWS::ApiGateway::RestApi
  Properties:
    Name: Service Checker Gateway
PageResource:
  Type: AWS::ApiGateway::Resource
  Properties:
    RestApiId: !Ref PageGateway
    ParentId:
      Fn::GetAtt:
      - PageGateway
      - RootResourceId
    PathPart: page
PageGatewayMethod:
  Type: AWS::ApiGateway::Method
  Properties:
    AuthorizationType: NONE
    HttpMethod: GET
    Integration:
      Type: AWS
      IntegrationHttpMethod: POST
      Uri:
        Fn::Sub: arn:aws:apigateway:${AWS::Region}:lambda:path/2015-03-31/functions/${WebRenderLambda.Arn}/invocations
      RequestTemplates:
        application/json: |
          {
              "method": "$context.httpMethod",
              "body" : $input.json('$'),
              "headers": {
                  #foreach($param in $input.params().header.keySet())
                  "$param": "$util.escapeJavaScript($input.params().header.get($param))"
                  #if($foreach.hasNext),#end
                  #end
              }
          }
      IntegrationResponses:
      - StatusCode: 200
        ResponseParameters:
          method.response.header.Content-Type: "'text/html'"
        ResponseTemplates:
          text/html: "$input.path('$')"
    ResourceId: !Ref PageResource
    RestApiId: !Ref PageGateway
    MethodResponses:
    - StatusCode: 200
      ResponseParameters:
        method.response.header.Content-Type: true
PageGatewayProdStage:
  Type: AWS::ApiGateway::Stage
  Properties:
    DeploymentId: !Ref PageGatewayDeployment
    RestApiId: !Ref PageGateway
    StageName: Prod
PageGatewayDeployment:
  Type: AWS::ApiGateway::Deployment
  DependsOn: PageGatewayMethod
  Properties:
    RestApiId: !Ref PageGateway
    Description: PageGateway deployment
    StageName: Stage

There’s a lot going on here, but the real meat is in the PageGatewayMethod section. There are a couple properties that deviate from the default which is why we couldn’t use the SAM transformer.

First, we’re passing request headers through to the Lambda in theRequestTemplates section. I’m doing this so I can validate incoming auth headers. The API Gateway can do some types of auth, but I found it easier to check auth myself in the Lambda function since the Gateway is designed to handle API calls and not browser requests.

Next, note that in the IntegrationResponses section we’re defining the Content-Type header to be ‘text/html’ (with single-quotes) and defining the ResponseTemplate to be $input.path(‘$’). This is what makes the request render as a HTML page in your browser instead of just raw text.

Due to the StageName and PathPart values in the other sections, your actual page will be accessible at https://someId.execute-api.region.amazonaws.com/Prod/page. I have the page behind an existing reverse-proxy and give it a saner URL for end-users. The reverse proxy also attaches the auth header I mentioned above. If that header isn’t present, the Lambda will render an error page instead so the proxy can’t be bypassed.

The Web Page Rendering Lambda
This Lambda is invoked by calls to the API Gateway and looks like:

# Web Page Lambda
WebRenderLambda:
  Type: AWS::Lambda::Function
  Properties:
    Code: ./lambda.zip
    Environment:
      Variables:
        TABLE_NAME: !Ref DynamoTable
    Handler: web.handler
    Role:
      Fn::GetAtt:
      - WebRenderLambdaRole
      - Arn
    Runtime: python3.6
    Timeout: 30
WebRenderLambdaRole:
  Type: AWS::IAM::Role
  Properties:
    ManagedPolicyArns:
    - arn:aws:iam::aws:policy/AmazonDynamoDBReadOnlyAccess
    - arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole
    AssumeRolePolicyDocument:
      Version: '2012-10-17'
      Statement:
      - Action:
        - sts:AssumeRole
        Effect: Allow
        Principal:
          Service:
          - lambda.amazonaws.com
WebRenderLambdaGatewayPermission:
  Type: AWS::Lambda::Permission
  Properties:
    FunctionName: !Ref WebRenderLambda
    Action: lambda:invokeFunction
    Principal: apigateway.amazonaws.com
    SourceArn:
      Fn::Sub:
      - arn:aws:execute-api:${AWS::Region}:${AWS::AccountId}:${__ApiId__}/*/*/*
      - __ApiId__: !Ref PageGateway

The WebRenderLambda and WebRenderLambdaRole should look familiar.

The WebRenderLambdaGatewayPermission is similar to the Status Checker’s CloudWatch permission, only this time it allows the API Gateway to invoke this Lambda.

The DynamoDB Table
This one is straightforward.

# DynamoDB table
DynamoTable:
  Type: AWS::DynamoDB::Table
  Properties:
    AttributeDefinitions:
    - AttributeName: name
      AttributeType: S
    ProvisionedThroughput:
      WriteCapacityUnits: 1
      ReadCapacityUnits: 1
    TableName: status-page-checker-results
    KeySchema:
    - KeyType: HASH
      AttributeName: name

The Deployment
We’ve made it this far defining every resource in a template that we can check in to version control, so we might as well script the deployment as well rather than manually manage the CloudFormation Stack via the AWS web console.

Since I’m using the packaging feature, I first run:

$ aws cloudformation package \
    --template-file template.yaml \
    --s3-bucket <some-bucket-name> \
    --output-template-file template-packaged.yaml
Uploading to 34cd6e82c5e8205f9b35e71afd9e1548 1922559 / 1922559.0 (100.00%) Successfully packaged artifacts and wrote output template to file template-packaged.yaml.

Then to deploy the template (whether new or modified), I run:

$ aws cloudformation deploy \
    --region '<aws-region>' \
    --template-file template-packaged.yaml \
    --stack-name '<some-name>' \
    --capabilities CAPABILITY_IAM
Waiting for changeset to be created.. Waiting for stack create/update to complete Successfully created/updated stack - <some-name>

And that’s it! You’ve just created a dynamic web page that will never require you to SSH anywhere, patch a server, recover from a disaster after Amazon terminates your unhealthy EC2, or any other number of pitfalls that are now the problem of some ops person at AWS. And you can reproduce deployments and make changes with confidence because everything is defined in the template and can be tracked in version control.

Best Practices for Running Apache Kafka on AWS

Post Syndicated from Prasad Alle original https://aws.amazon.com/blogs/big-data/best-practices-for-running-apache-kafka-on-aws/

This post was written in partnership with Intuit to share learnings, best practices, and recommendations for running an Apache Kafka cluster on AWS. Thanks to Vaishak Suresh and his colleagues at Intuit for their contribution and support.

Intuit, in their own words: Intuit, a leading enterprise customer for AWS, is a creator of business and financial management solutions. For more information on how Intuit partners with AWS, see our previous blog post, Real-time Stream Processing Using Apache Spark Streaming and Apache Kafka on AWS. Apache Kafka is an open-source, distributed streaming platform that enables you to build real-time streaming applications.

The best practices described in this post are based on our experience in running and operating large-scale Kafka clusters on AWS for more than two years. Our intent for this post is to help AWS customers who are currently running Kafka on AWS, and also customers who are considering migrating on-premises Kafka deployments to AWS.

AWS offers Amazon Kinesis Data Streams, a Kafka alternative that is fully managed.

Running your Kafka deployment on Amazon EC2 provides a high performance, scalable solution for ingesting streaming data. AWS offers many different instance types and storage option combinations for Kafka deployments. However, given the number of possible deployment topologies, it’s not always trivial to select the most appropriate strategy suitable for your use case.

In this blog post, we cover the following aspects of running Kafka clusters on AWS:

  • Deployment considerations and patterns
  • Storage options
  • Instance types
  • Networking
  • Upgrades
  • Performance tuning
  • Monitoring
  • Security
  • Backup and restore

Note: While implementing Kafka clusters in a production environment, make sure also to consider factors like your number of messages, message size, monitoring, failure handling, and any operational issues.

Deployment considerations and patterns

In this section, we discuss various deployment options available for Kafka on AWS, along with pros and cons of each option. A successful deployment starts with thoughtful consideration of these options. Considering availability, consistency, and operational overhead of the deployment helps when choosing the right option.

Single AWS Region, Three Availability Zones, All Active

One typical deployment pattern (all active) is in a single AWS Region with three Availability Zones (AZs). One Kafka cluster is deployed in each AZ along with Apache ZooKeeper and Kafka producer and consumer instances as shown in the illustration following.

In this pattern, this is the Kafka cluster deployment:

  • Kafka producers and Kafka cluster are deployed on each AZ.
  • Data is distributed evenly across three Kafka clusters by using Elastic Load Balancer.
  • Kafka consumers aggregate data from all three Kafka clusters.

Kafka cluster failover occurs this way:

  • Mark down all Kafka producers
  • Stop consumers
  • Debug and restack Kafka
  • Restart consumers
  • Restart Kafka producers

Following are the pros and cons of this pattern.

Pros Cons
  • Highly available
  • Can sustain the failure of two AZs
  • No message loss during failover
  • Simple deployment

 

  • Very high operational overhead:
    • All changes need to be deployed three times, one for each Kafka cluster
    • Maintaining and monitoring three Kafka clusters
    • Maintaining and monitoring three consumer clusters

A restart is required for patching and upgrading brokers in a Kafka cluster. In this approach, a rolling upgrade is done separately for each cluster.

Single Region, Three Availability Zones, Active-Standby

Another typical deployment pattern (active-standby) is in a single AWS Region with a single Kafka cluster and Kafka brokers and Zookeepers distributed across three AZs. Another similar Kafka cluster acts as a standby as shown in the illustration following. You can use Kafka mirroring with MirrorMaker to replicate messages between any two clusters.

In this pattern, this is the Kafka cluster deployment:

  • Kafka producers are deployed on all three AZs.
  • Only one Kafka cluster is deployed across three AZs (active).
  • ZooKeeper instances are deployed on each AZ.
  • Brokers are spread evenly across all three AZs.
  • Kafka consumers can be deployed across all three AZs.
  • Standby Kafka producers and a Multi-AZ Kafka cluster are part of the deployment.

Kafka cluster failover occurs this way:

  • Switch traffic to standby Kafka producers cluster and Kafka cluster.
  • Restart consumers to consume from standby Kafka cluster.

Following are the pros and cons of this pattern.

Pros Cons
  • Less operational overhead when compared to the first option
  • Only one Kafka cluster to manage and consume data from
  • Can handle single AZ failures without activating a standby Kafka cluster
  • Added latency due to cross-AZ data transfer among Kafka brokers
  • For Kafka versions before 0.10, replicas for topic partitions have to be assigned so they’re distributed to the brokers on different AZs (rack-awareness)
  • The cluster can become unavailable in case of a network glitch, where ZooKeeper does not see Kafka brokers
  • Possibility of in-transit message loss during failover

Intuit recommends using a single Kafka cluster in one AWS Region, with brokers distributing across three AZs (single region, three AZs). This approach offers stronger fault tolerance than otherwise, because a failed AZ won’t cause Kafka downtime.

Storage options

There are two storage options for file storage in Amazon EC2:

Ephemeral storage is local to the Amazon EC2 instance. It can provide high IOPS based on the instance type. On the other hand, Amazon EBS volumes offer higher resiliency and you can configure IOPS based on your storage needs. EBS volumes also offer some distinct advantages in terms of recovery time. Your choice of storage is closely related to the type of workload supported by your Kafka cluster.

Kafka provides built-in fault tolerance by replicating data partitions across a configurable number of instances. If a broker fails, you can recover it by fetching all the data from other brokers in the cluster that host the other replicas. Depending on the size of the data transfer, it can affect recovery process and network traffic. These in turn eventually affect the cluster’s performance.

The following table contrasts the benefits of using an instance store versus using EBS for storage.

Instance store EBS
  • Instance storage is recommended for large- and medium-sized Kafka clusters. For a large cluster, read/write traffic is distributed across a high number of brokers, so the loss of a broker has less of an impact. However, for smaller clusters, a quick recovery for the failed node is important, but a failed broker takes longer and requires more network traffic for a smaller Kafka cluster.
  • Storage-optimized instances like h1, i3, and d2 are an ideal choice for distributed applications like Kafka.

 

  • The primary advantage of using EBS in a Kafka deployment is that it significantly reduces data-transfer traffic when a broker fails or must be replaced. The replacement broker joins the cluster much faster.
  • Data stored on EBS is persisted in case of an instance failure or termination. The broker’s data stored on an EBS volume remains intact, and you can mount the EBS volume to a new EC2 instance. Most of the replicated data for the replacement broker is already available in the EBS volume and need not be copied over the network from another broker. Only the changes made after the original broker failure need to be transferred across the network. That makes this process much faster.

 

 

Intuit chose EBS because of their frequent instance restacking requirements and also other benefits provided by EBS.

Generally, Kafka deployments use a replication factor of three. EBS offers replication within their service, so Intuit chose a replication factor of two instead of three.

Instance types

The choice of instance types is generally driven by the type of storage required for your streaming applications on a Kafka cluster. If your application requires ephemeral storage, h1, i3, and d2 instances are your best option.

Intuit used r3.xlarge instances for their brokers and r3.large for ZooKeeper, with ST1 (throughput optimized HDD) EBS for their Kafka cluster.

Here are sample benchmark numbers from Intuit tests.

Configuration Broker bytes (MB/s)
  • r3.xlarge
  • ST1 EBS
  • 12 brokers
  • 12 partitions

 

Aggregate 346.9

If you need EBS storage, then AWS has a newer-generation r4 instance. The r4 instance is superior to R3 in many ways:

  • It has a faster processor (Broadwell).
  • EBS is optimized by default.
  • It features networking based on Elastic Network Adapter (ENA), with up to 10 Gbps on smaller sizes.
  • It costs 20 percent less than R3.

Note: It’s always best practice to check for the latest changes in instance types.

Networking

The network plays a very important role in a distributed system like Kafka. A fast and reliable network ensures that nodes can communicate with each other easily. The available network throughput controls the maximum amount of traffic that Kafka can handle. Network throughput, combined with disk storage, is often the governing factor for cluster sizing.

If you expect your cluster to receive high read/write traffic, select an instance type that offers 10-Gb/s performance.

In addition, choose an option that keeps interbroker network traffic on the private subnet, because this approach allows clients to connect to the brokers. Communication between brokers and clients uses the same network interface and port. For more details, see the documentation about IP addressing for EC2 instances.

If you are deploying in more than one AWS Region, you can connect the two VPCs in the two AWS Regions using cross-region VPC peering. However, be aware of the networking costs associated with cross-AZ deployments.

Upgrades

Kafka has a history of not being backward compatible, but its support of backward compatibility is getting better. During a Kafka upgrade, you should keep your producer and consumer clients on a version equal to or lower than the version you are upgrading from. After the upgrade is finished, you can start using a new protocol version and any new features it supports. There are three upgrade approaches available, discussed following.

Rolling or in-place upgrade

In a rolling or in-place upgrade scenario, upgrade one Kafka broker at a time. Take into consideration the recommendations for doing rolling restarts to avoid downtime for end users.

Downtime upgrade

If you can afford the downtime, you can take your entire cluster down, upgrade each Kafka broker, and then restart the cluster.

Blue/green upgrade

Intuit followed the blue/green deployment model for their workloads, as described following.

If you can afford to create a separate Kafka cluster and upgrade it, we highly recommend the blue/green upgrade scenario. In this scenario, we recommend that you keep your clusters up-to-date with the latest Kafka version. For additional details on Kafka version upgrades or more details, see the Kafka upgrade documentation.

The following illustration shows a blue/green upgrade.

In this scenario, the upgrade plan works like this:

  • Create a new Kafka cluster on AWS.
  • Create a new Kafka producers stack to point to the new Kafka cluster.
  • Create topics on the new Kafka cluster.
  • Test the green deployment end to end (sanity check).
  • Using Amazon Route 53, change the new Kafka producers stack on AWS to point to the new green Kafka environment that you have created.

The roll-back plan works like this:

  • Switch Amazon Route 53 to the old Kafka producers stack on AWS to point to the old Kafka environment.

For additional details on blue/green deployment architecture using Kafka, see the re:Invent presentation Leveraging the Cloud with a Blue-Green Deployment Architecture.

Performance tuning

You can tune Kafka performance in multiple dimensions. Following are some best practices for performance tuning.

 These are some general performance tuning techniques:

  • If throughput is less than network capacity, try the following:
    • Add more threads
    • Increase batch size
    • Add more producer instances
    • Add more partitions
  • To improve latency when acks =-1, increase your num.replica.fetches value.
  • For cross-AZ data transfer, tune your buffer settings for sockets and for OS TCP.
  • Make sure that num.io.threads is greater than the number of disks dedicated for Kafka.
  • Adjust num.network.threads based on the number of producers plus the number of consumers plus the replication factor.
  • Your message size affects your network bandwidth. To get higher performance from a Kafka cluster, select an instance type that offers 10 Gb/s performance.

For Java and JVM tuning, try the following:

  • Minimize GC pauses by using the Oracle JDK, which uses the new G1 garbage-first collector.
  • Try to keep the Kafka heap size below 4 GB.

Monitoring

Knowing whether a Kafka cluster is working correctly in a production environment is critical. Sometimes, just knowing that the cluster is up is enough, but Kafka applications have many moving parts to monitor. In fact, it can easily become confusing to understand what’s important to watch and what you can set aside. Items to monitor range from simple metrics about the overall rate of traffic, to producers, consumers, brokers, controller, ZooKeeper, topics, partitions, messages, and so on.

For monitoring, Intuit used several tools, including Newrelec, Wavefront, Amazon CloudWatch, and AWS CloudTrail. Our recommended monitoring approach follows.

For system metrics, we recommend that you monitor:

  • CPU load
  • Network metrics
  • File handle usage
  • Disk space
  • Disk I/O performance
  • Garbage collection
  • ZooKeeper

For producers, we recommend that you monitor:

  • Batch-size-avg
  • Compression-rate-avg
  • Waiting-threads
  • Buffer-available-bytes
  • Record-queue-time-max
  • Record-send-rate
  • Records-per-request-avg

For consumers, we recommend that you monitor:

  • Batch-size-avg
  • Compression-rate-avg
  • Waiting-threads
  • Buffer-available-bytes
  • Record-queue-time-max
  • Record-send-rate
  • Records-per-request-avg

Security

Like most distributed systems, Kafka provides the mechanisms to transfer data with relatively high security across the components involved. Depending on your setup, security might involve different services such as encryption, Kerberos, Transport Layer Security (TLS) certificates, and advanced access control list (ACL) setup in brokers and ZooKeeper. The following tells you more about the Intuit approach. For details on Kafka security not covered in this section, see the Kafka documentation.

Encryption at rest

For EBS-backed EC2 instances, you can enable encryption at rest by using Amazon EBS volumes with encryption enabled. Amazon EBS uses AWS Key Management Service (AWS KMS) for encryption. For more details, see Amazon EBS Encryption in the EBS documentation. For instance store–backed EC2 instances, you can enable encryption at rest by using Amazon EC2 instance store encryption.

Encryption in transit

Kafka uses TLS for client and internode communications.

Authentication

Authentication of connections to brokers from clients (producers and consumers) to other brokers and tools uses either Secure Sockets Layer (SSL) or Simple Authentication and Security Layer (SASL).

Kafka supports Kerberos authentication. If you already have a Kerberos server, you can add Kafka to your current configuration.

Authorization

In Kafka, authorization is pluggable and integration with external authorization services is supported.

Backup and restore

The type of storage used in your deployment dictates your backup and restore strategy.

The best way to back up a Kafka cluster based on instance storage is to set up a second cluster and replicate messages using MirrorMaker. Kafka’s mirroring feature makes it possible to maintain a replica of an existing Kafka cluster. Depending on your setup and requirements, your backup cluster might be in the same AWS Region as your main cluster or in a different one.

For EBS-based deployments, you can enable automatic snapshots of EBS volumes to back up volumes. You can easily create new EBS volumes from these snapshots to restore. We recommend storing backup files in Amazon S3.

For more information on how to back up in Kafka, see the Kafka documentation.

Conclusion

In this post, we discussed several patterns for running Kafka in the AWS Cloud. AWS also provides an alternative managed solution with Amazon Kinesis Data Streams, there are no servers to manage or scaling cliffs to worry about, you can scale the size of your streaming pipeline in seconds without downtime, data replication across availability zones is automatic, you benefit from security out of the box, Kinesis Data Streams is tightly integrated with a wide variety of AWS services like Lambda, Redshift, Elasticsearch and it supports open source frameworks like Storm, Spark, Flink, and more. You may refer to kafka-kinesis connector.

If you have questions or suggestions, please comment below.


Additional Reading

If you found this post useful, be sure to check out Implement Serverless Log Analytics Using Amazon Kinesis Analytics and Real-time Clickstream Anomaly Detection with Amazon Kinesis Analytics.


About the Author

Prasad Alle is a Senior Big Data Consultant with AWS Professional Services. He spends his time leading and building scalable, reliable Big data, Machine learning, Artificial Intelligence and IoT solutions for AWS Enterprise and Strategic customers. His interests extend to various technologies such as Advanced Edge Computing, Machine learning at Edge. In his spare time, he enjoys spending time with his family.

 

 

Best Practices for Running Apache Cassandra on Amazon EC2

Post Syndicated from Prasad Alle original https://aws.amazon.com/blogs/big-data/best-practices-for-running-apache-cassandra-on-amazon-ec2/

Apache Cassandra is a commonly used, high performance NoSQL database. AWS customers that currently maintain Cassandra on-premises may want to take advantage of the scalability, reliability, security, and economic benefits of running Cassandra on Amazon EC2.

Amazon EC2 and Amazon Elastic Block Store (Amazon EBS) provide secure, resizable compute capacity and storage in the AWS Cloud. When combined, you can deploy Cassandra, allowing you to scale capacity according to your requirements. Given the number of possible deployment topologies, it’s not always trivial to select the most appropriate strategy suitable for your use case.

In this post, we outline three Cassandra deployment options, as well as provide guidance about determining the best practices for your use case in the following areas:

  • Cassandra resource overview
  • Deployment considerations
  • Storage options
  • Networking
  • High availability and resiliency
  • Maintenance
  • Security

Before we jump into best practices for running Cassandra on AWS, we should mention that we have many customers who decided to use DynamoDB instead of managing their own Cassandra cluster. DynamoDB is fully managed, serverless, and provides multi-master cross-region replication, encryption at rest, and managed backup and restore. Integration with AWS Identity and Access Management (IAM) enables DynamoDB customers to implement fine-grained access control for their data security needs.

Several customers who have been using large Cassandra clusters for many years have moved to DynamoDB to eliminate the complications of administering Cassandra clusters and maintaining high availability and durability themselves. Gumgum.com is one customer who migrated to DynamoDB and observed significant savings. For more information, see Moving to Amazon DynamoDB from Hosted Cassandra: A Leap Towards 60% Cost Saving per Year.

AWS provides options, so you’re covered whether you want to run your own NoSQL Cassandra database, or move to a fully managed, serverless DynamoDB database.

Cassandra resource overview

Here’s a short introduction to standard Cassandra resources and how they are implemented with AWS infrastructure. If you’re already familiar with Cassandra or AWS deployments, this can serve as a refresher.

Resource Cassandra AWS
Cluster

A single Cassandra deployment.

 

This typically consists of multiple physical locations, keyspaces, and physical servers.

A logical deployment construct in AWS that maps to an AWS CloudFormation StackSet, which consists of one or many CloudFormation stacks to deploy Cassandra.
Datacenter A group of nodes configured as a single replication group.

A logical deployment construct in AWS.

 

A datacenter is deployed with a single CloudFormation stack consisting of Amazon EC2 instances, networking, storage, and security resources.

Rack

A collection of servers.

 

A datacenter consists of at least one rack. Cassandra tries to place the replicas on different racks.

A single Availability Zone.
Server/node A physical virtual machine running Cassandra software. An EC2 instance.
Token Conceptually, the data managed by a cluster is represented as a ring. The ring is then divided into ranges equal to the number of nodes. Each node being responsible for one or more ranges of the data. Each node gets assigned with a token, which is essentially a random number from the range. The token value determines the node’s position in the ring and its range of data. Managed within Cassandra.
Virtual node (vnode) Responsible for storing a range of data. Each vnode receives one token in the ring. A cluster (by default) consists of 256 tokens, which are uniformly distributed across all servers in the Cassandra datacenter. Managed within Cassandra.
Replication factor The total number of replicas across the cluster. Managed within Cassandra.

Deployment considerations

One of the many benefits of deploying Cassandra on Amazon EC2 is that you can automate many deployment tasks. In addition, AWS includes services, such as CloudFormation, that allow you to describe and provision all your infrastructure resources in your cloud environment.

We recommend orchestrating each Cassandra ring with one CloudFormation template. If you are deploying in multiple AWS Regions, you can use a CloudFormation StackSet to manage those stacks. All the maintenance actions (scaling, upgrading, and backing up) should be scripted with an AWS SDK. These may live as standalone AWS Lambda functions that can be invoked on demand during maintenance.

You can get started by following the Cassandra Quick Start deployment guide. Keep in mind that this guide does not address the requirements to operate a production deployment and should be used only for learning more about Cassandra.

Deployment patterns

In this section, we discuss various deployment options available for Cassandra in Amazon EC2. A successful deployment starts with thoughtful consideration of these options. Consider the amount of data, network environment, throughput, and availability.

  • Single AWS Region, 3 Availability Zones
  • Active-active, multi-Region
  • Active-standby, multi-Region

Single region, 3 Availability Zones

In this pattern, you deploy the Cassandra cluster in one AWS Region and three Availability Zones. There is only one ring in the cluster. By using EC2 instances in three zones, you ensure that the replicas are distributed uniformly in all zones.

To ensure the even distribution of data across all Availability Zones, we recommend that you distribute the EC2 instances evenly in all three Availability Zones. The number of EC2 instances in the cluster is a multiple of three (the replication factor).

This pattern is suitable in situations where the application is deployed in one Region or where deployments in different Regions should be constrained to the same Region because of data privacy or other legal requirements.

Pros Cons

●     Highly available, can sustain failure of one Availability Zone.

●     Simple deployment

●     Does not protect in a situation when many of the resources in a Region are experiencing intermittent failure.

 

Active-active, multi-Region

In this pattern, you deploy two rings in two different Regions and link them. The VPCs in the two Regions are peered so that data can be replicated between two rings.

We recommend that the two rings in the two Regions be identical in nature, having the same number of nodes, instance types, and storage configuration.

This pattern is most suitable when the applications using the Cassandra cluster are deployed in more than one Region.

Pros Cons

●     No data loss during failover.

●     Highly available, can sustain when many of the resources in a Region are experiencing intermittent failures.

●     Read/write traffic can be localized to the closest Region for the user for lower latency and higher performance.

●     High operational overhead

●     The second Region effectively doubles the cost

 

Active-standby, multi-region

In this pattern, you deploy two rings in two different Regions and link them. The VPCs in the two Regions are peered so that data can be replicated between two rings.

However, the second Region does not receive traffic from the applications. It only functions as a secondary location for disaster recovery reasons. If the primary Region is not available, the second Region receives traffic.

We recommend that the two rings in the two Regions be identical in nature, having the same number of nodes, instance types, and storage configuration.

This pattern is most suitable when the applications using the Cassandra cluster require low recovery point objective (RPO) and recovery time objective (RTO).

Pros Cons

●     No data loss during failover.

●     Highly available, can sustain failure or partitioning of one whole Region.

●     High operational overhead.

●     High latency for writes for eventual consistency.

●     The second Region effectively doubles the cost.

Storage options

In on-premises deployments, Cassandra deployments use local disks to store data. There are two storage options for EC2 instances:

Your choice of storage is closely related to the type of workload supported by the Cassandra cluster. Instance store works best for most general purpose Cassandra deployments. However, in certain read-heavy clusters, Amazon EBS is a better choice.

The choice of instance type is generally driven by the type of storage:

  • If ephemeral storage is required for your application, a storage-optimized (I3) instance is the best option.
  • If your workload requires Amazon EBS, it is best to go with compute-optimized (C5) instances.
  • Burstable instance types (T2) don’t offer good performance for Cassandra deployments.

Instance store

Ephemeral storage is local to the EC2 instance. It may provide high input/output operations per second (IOPs) based on the instance type. An SSD-based instance store can support up to 3.3M IOPS in I3 instances. This high performance makes it an ideal choice for transactional or write-intensive applications such as Cassandra.

In general, instance storage is recommended for transactional, large, and medium-size Cassandra clusters. For a large cluster, read/write traffic is distributed across a higher number of nodes, so the loss of one node has less of an impact. However, for smaller clusters, a quick recovery for the failed node is important.

As an example, for a cluster with 100 nodes, the loss of 1 node is 3.33% loss (with a replication factor of 3). Similarly, for a cluster with 10 nodes, the loss of 1 node is 33% less capacity (with a replication factor of 3).

  Ephemeral storage Amazon EBS Comments

IOPS

(translates to higher query performance)

Up to 3.3M on I3

80K/instance

10K/gp2/volume

32K/io1/volume

This results in a higher query performance on each host. However, Cassandra implicitly scales well in terms of horizontal scale. In general, we recommend scaling horizontally first. Then, scale vertically to mitigate specific issues.

 

Note: 3.3M IOPS is observed with 100% random read with a 4-KB block size on Amazon Linux.

AWS instance types I3 Compute optimized, C5 Being able to choose between different instance types is an advantage in terms of CPU, memory, etc., for horizontal and vertical scaling.
Backup/ recovery Custom Basic building blocks are available from AWS.

Amazon EBS offers distinct advantage here. It is small engineering effort to establish a backup/restore strategy.

a) In case of an instance failure, the EBS volumes from the failing instance are attached to a new instance.

b) In case of an EBS volume failure, the data is restored by creating a new EBS volume from last snapshot.

Amazon EBS

EBS volumes offer higher resiliency, and IOPs can be configured based on your storage needs. EBS volumes also offer some distinct advantages in terms of recovery time. EBS volumes can support up to 32K IOPS per volume and up to 80K IOPS per instance in RAID configuration. They have an annualized failure rate (AFR) of 0.1–0.2%, which makes EBS volumes 20 times more reliable than typical commodity disk drives.

The primary advantage of using Amazon EBS in a Cassandra deployment is that it reduces data-transfer traffic significantly when a node fails or must be replaced. The replacement node joins the cluster much faster. However, Amazon EBS could be more expensive, depending on your data storage needs.

Cassandra has built-in fault tolerance by replicating data to partitions across a configurable number of nodes. It can not only withstand node failures but if a node fails, it can also recover by copying data from other replicas into a new node. Depending on your application, this could mean copying tens of gigabytes of data. This adds additional delay to the recovery process, increases network traffic, and could possibly impact the performance of the Cassandra cluster during recovery.

Data stored on Amazon EBS is persisted in case of an instance failure or termination. The node’s data stored on an EBS volume remains intact and the EBS volume can be mounted to a new EC2 instance. Most of the replicated data for the replacement node is already available in the EBS volume and won’t need to be copied over the network from another node. Only the changes made after the original node failed need to be transferred across the network. That makes this process much faster.

EBS volumes are snapshotted periodically. So, if a volume fails, a new volume can be created from the last known good snapshot and be attached to a new instance. This is faster than creating a new volume and coping all the data to it.

Most Cassandra deployments use a replication factor of three. However, Amazon EBS does its own replication under the covers for fault tolerance. In practice, EBS volumes are about 20 times more reliable than typical disk drives. So, it is possible to go with a replication factor of two. This not only saves cost, but also enables deployments in a region that has two Availability Zones.

EBS volumes are recommended in case of read-heavy, small clusters (fewer nodes) that require storage of a large amount of data. Keep in mind that the Amazon EBS provisioned IOPS could get expensive. General purpose EBS volumes work best when sized for required performance.

Networking

If your cluster is expected to receive high read/write traffic, select an instance type that offers 10–Gb/s performance. As an example, i3.8xlarge and c5.9xlarge both offer 10–Gb/s networking performance. A smaller instance type in the same family leads to a relatively lower networking throughput.

Cassandra generates a universal unique identifier (UUID) for each node based on IP address for the instance. This UUID is used for distributing vnodes on the ring.

In the case of an AWS deployment, IP addresses are assigned automatically to the instance when an EC2 instance is created. With the new IP address, the data distribution changes and the whole ring has to be rebalanced. This is not desirable.

To preserve the assigned IP address, use a secondary elastic network interface with a fixed IP address. Before swapping an EC2 instance with a new one, detach the secondary network interface from the old instance and attach it to the new one. This way, the UUID remains same and there is no change in the way that data is distributed in the cluster.

If you are deploying in more than one region, you can connect the two VPCs in two regions using cross-region VPC peering.

High availability and resiliency

Cassandra is designed to be fault-tolerant and highly available during multiple node failures. In the patterns described earlier in this post, you deploy Cassandra to three Availability Zones with a replication factor of three. Even though it limits the AWS Region choices to the Regions with three or more Availability Zones, it offers protection for the cases of one-zone failure and network partitioning within a single Region. The multi-Region deployments described earlier in this post protect when many of the resources in a Region are experiencing intermittent failure.

Resiliency is ensured through infrastructure automation. The deployment patterns all require a quick replacement of the failing nodes. In the case of a regionwide failure, when you deploy with the multi-Region option, traffic can be directed to the other active Region while the infrastructure is recovering in the failing Region. In the case of unforeseen data corruption, the standby cluster can be restored with point-in-time backups stored in Amazon S3.

Maintenance

In this section, we look at ways to ensure that your Cassandra cluster is healthy:

  • Scaling
  • Upgrades
  • Backup and restore

Scaling

Cassandra is horizontally scaled by adding more instances to the ring. We recommend doubling the number of nodes in a cluster to scale up in one scale operation. This leaves the data homogeneously distributed across Availability Zones. Similarly, when scaling down, it’s best to halve the number of instances to keep the data homogeneously distributed.

Cassandra is vertically scaled by increasing the compute power of each node. Larger instance types have proportionally bigger memory. Use deployment automation to swap instances for bigger instances without downtime or data loss.

Upgrades

All three types of upgrades (Cassandra, operating system patching, and instance type changes) follow the same rolling upgrade pattern.

In this process, you start with a new EC2 instance and install software and patches on it. Thereafter, remove one node from the ring. For more information, see Cassandra cluster Rolling upgrade. Then, you detach the secondary network interface from one of the EC2 instances in the ring and attach it to the new EC2 instance. Restart the Cassandra service and wait for it to sync. Repeat this process for all nodes in the cluster.

Backup and restore

Your backup and restore strategy is dependent on the type of storage used in the deployment. Cassandra supports snapshots and incremental backups. When using instance store, a file-based backup tool works best. Customers use rsync or other third-party products to copy data backups from the instance to long-term storage. For more information, see Backing up and restoring data in the DataStax documentation. This process has to be repeated for all instances in the cluster for a complete backup. These backup files are copied back to new instances to restore. We recommend using S3 to durably store backup files for long-term storage.

For Amazon EBS based deployments, you can enable automated snapshots of EBS volumes to back up volumes. New EBS volumes can be easily created from these snapshots for restoration.

Security

We recommend that you think about security in all aspects of deployment. The first step is to ensure that the data is encrypted at rest and in transit. The second step is to restrict access to unauthorized users. For more information about security, see the Cassandra documentation.

Encryption at rest

Encryption at rest can be achieved by using EBS volumes with encryption enabled. Amazon EBS uses AWS KMS for encryption. For more information, see Amazon EBS Encryption.

Instance store–based deployments require using an encrypted file system or an AWS partner solution. If you are using DataStax Enterprise, it supports transparent data encryption.

Encryption in transit

Cassandra uses Transport Layer Security (TLS) for client and internode communications.

Authentication

The security mechanism is pluggable, which means that you can easily swap out one authentication method for another. You can also provide your own method of authenticating to Cassandra, such as a Kerberos ticket, or if you want to store passwords in a different location, such as an LDAP directory.

Authorization

The authorizer that’s plugged in by default is org.apache.cassandra.auth.Allow AllAuthorizer. Cassandra also provides a role-based access control (RBAC) capability, which allows you to create roles and assign permissions to these roles.

Conclusion

In this post, we discussed several patterns for running Cassandra in the AWS Cloud. This post describes how you can manage Cassandra databases running on Amazon EC2. AWS also provides managed offerings for a number of databases. To learn more, see Purpose-built databases for all your application needs.

If you have questions or suggestions, please comment below.


Additional Reading

If you found this post useful, be sure to check out Analyze Your Data on Amazon DynamoDB with Apache Spark and Analysis of Top-N DynamoDB Objects using Amazon Athena and Amazon QuickSight.


About the Authors

Prasad Alle is a Senior Big Data Consultant with AWS Professional Services. He spends his time leading and building scalable, reliable Big data, Machine learning, Artificial Intelligence and IoT solutions for AWS Enterprise and Strategic customers. His interests extend to various technologies such as Advanced Edge Computing, Machine learning at Edge. In his spare time, he enjoys spending time with his family.

 

 

 

Provanshu Dey is a Senior IoT Consultant with AWS Professional Services. He works on highly scalable and reliable IoT, data and machine learning solutions with our customers. In his spare time, he enjoys spending time with his family and tinkering with electronics & gadgets.