Tag Archives: column

Monitoring your Amazon SNS message filtering activity with Amazon CloudWatch

Post Syndicated from Rachel Richardson original https://aws.amazon.com/blogs/compute/monitoring-your-amazon-sns-message-filtering-activity-with-amazon-cloudwatch/

This post is courtesy of Otavio Ferreira, Manager, Amazon SNS, AWS Messaging.

Amazon SNS message filtering provides a set of string and numeric matching operators that allow each subscription to receive only the messages of interest. Hence, SNS message filtering can simplify your pub/sub messaging architecture by offloading the message filtering logic from your subscriber systems, as well as the message routing logic from your publisher systems.

After you set the subscription attribute that defines a filter policy, the subscribing endpoint receives only the messages that carry attributes matching this filter policy. Other messages published to the topic are filtered out for this subscription. In this way, the native integration between SNS and Amazon CloudWatch provides visibility into the number of messages delivered, as well as the number of messages filtered out.

CloudWatch metrics are captured automatically for you. To get started with SNS message filtering, see Filtering Messages with Amazon SNS.

Message Filtering Metrics

The following six CloudWatch metrics are relevant to understanding your SNS message filtering activity:

  • NumberOfMessagesPublished – Inbound traffic to SNS. This metric tracks all the messages that have been published to the topic.
  • NumberOfNotificationsDelivered – Outbound traffic from SNS. This metric tracks all the messages that have been successfully delivered to endpoints subscribed to the topic. A delivery takes place either when the incoming message attributes match a subscription filter policy, or when the subscription has no filter policy at all, which results in a catch-all behavior.
  • NumberOfNotificationsFilteredOut – This metric tracks all the messages that were filtered out because they carried attributes that didn’t match the subscription filter policy.
  • NumberOfNotificationsFilteredOut-NoMessageAttributes – This metric tracks all the messages that were filtered out because they didn’t carry any attributes at all and, consequently, didn’t match the subscription filter policy.
  • NumberOfNotificationsFilteredOut-InvalidAttributes – This metric keeps track of messages that were filtered out because they carried invalid or malformed attributes and, thus, didn’t match the subscription filter policy.
  • NumberOfNotificationsFailed – This last metric tracks all the messages that failed to be delivered to subscribing endpoints, regardless of whether a filter policy had been set for the endpoint. This metric is emitted after the message delivery retry policy is exhausted, and SNS stops attempting to deliver the message. At that moment, the subscribing endpoint is likely no longer reachable. For example, the subscribing SQS queue or Lambda function has been deleted by its owner. You may want to closely monitor this metric to address message delivery issues quickly.

Message filtering graphs

Through the AWS Management Console, you can compose graphs to display your SNS message filtering activity. The graph shows the number of messages published, delivered, and filtered out within the timeframe you specify (1h, 3h, 12h, 1d, 3d, 1w, or custom).

SNS message filtering for CloudWatch Metrics

To compose an SNS message filtering graph with CloudWatch:

  1. Open the CloudWatch console.
  2. Choose Metrics, SNS, All Metrics, and Topic Metrics.
  3. Select all metrics to add to the graph, such as:
    • NumberOfMessagesPublished
    • NumberOfNotificationsDelivered
    • NumberOfNotificationsFilteredOut
  4. Choose Graphed metrics.
  5. In the Statistic column, switch from Average to Sum.
  6. Title your graph with a descriptive name, such as “SNS Message Filtering”

After you have your graph set up, you may want to copy the graph link for bookmarking, emailing, or sharing with co-workers. You may also want to add your graph to a CloudWatch dashboard for easy access in the future. Both actions are available to you on the Actions menu, which is found above the graph.

Summary

SNS message filtering defines how SNS topics behave in terms of message delivery. By using CloudWatch metrics, you gain visibility into the number of messages published, delivered, and filtered out. This enables you to validate the operation of filter policies and more easily troubleshoot during development phases.

SNS message filtering can be implemented easily with existing AWS SDKs by applying message and subscription attributes across all SNS supported protocols (Amazon SQS, AWS Lambda, HTTP, SMS, email, and mobile push). CloudWatch metrics for SNS message filtering is available now, in all AWS Regions.

For information about pricing, see the CloudWatch pricing page.

For more information, see:

Analyze Apache Parquet optimized data using Amazon Kinesis Data Firehose, Amazon Athena, and Amazon Redshift

Post Syndicated from Roy Hasson original https://aws.amazon.com/blogs/big-data/analyzing-apache-parquet-optimized-data-using-amazon-kinesis-data-firehose-amazon-athena-and-amazon-redshift/

Amazon Kinesis Data Firehose is the easiest way to capture and stream data into a data lake built on Amazon S3. This data can be anything—from AWS service logs like AWS CloudTrail log files, Amazon VPC Flow Logs, Application Load Balancer logs, and others. It can also be IoT events, game events, and much more. To efficiently query this data, a time-consuming ETL (extract, transform, and load) process is required to massage and convert the data to an optimal file format, which increases the time to insight. This situation is less than ideal, especially for real-time data that loses its value over time.

To solve this common challenge, Kinesis Data Firehose can now save data to Amazon S3 in Apache Parquet or Apache ORC format. These are optimized columnar formats that are highly recommended for best performance and cost-savings when querying data in S3. This feature directly benefits you if you use Amazon Athena, Amazon Redshift, AWS Glue, Amazon EMR, or any other big data tools that are available from the AWS Partner Network and through the open-source community.

Amazon Connect is a simple-to-use, cloud-based contact center service that makes it easy for any business to provide a great customer experience at a lower cost than common alternatives. Its open platform design enables easy integration with other systems. One of those systems is Amazon Kinesis—in particular, Kinesis Data Streams and Kinesis Data Firehose.

What’s really exciting is that you can now save events from Amazon Connect to S3 in Apache Parquet format. You can then perform analytics using Amazon Athena and Amazon Redshift Spectrum in real time, taking advantage of this key performance and cost optimization. Of course, Amazon Connect is only one example. This new capability opens the door for a great deal of opportunity, especially as organizations continue to build their data lakes.

Amazon Connect includes an array of analytics views in the Administrator dashboard. But you might want to run other types of analysis. In this post, I describe how to set up a data stream from Amazon Connect through Kinesis Data Streams and Kinesis Data Firehose and out to S3, and then perform analytics using Athena and Amazon Redshift Spectrum. I focus primarily on the Kinesis Data Firehose support for Parquet and its integration with the AWS Glue Data Catalog, Amazon Athena, and Amazon Redshift.

Solution overview

Here is how the solution is laid out:

 

 

The following sections walk you through each of these steps to set up the pipeline.

1. Define the schema

When Kinesis Data Firehose processes incoming events and converts the data to Parquet, it needs to know which schema to apply. The reason is that many times, incoming events contain all or some of the expected fields based on which values the producers are advertising. A typical process is to normalize the schema during a batch ETL job so that you end up with a consistent schema that can easily be understood and queried. Doing this introduces latency due to the nature of the batch process. To overcome this issue, Kinesis Data Firehose requires the schema to be defined in advance.

To see the available columns and structures, see Amazon Connect Agent Event Streams. For the purpose of simplicity, I opted to make all the columns of type String rather than create the nested structures. But you can definitely do that if you want.

The simplest way to define the schema is to create a table in the Amazon Athena console. Open the Athena console, and paste the following create table statement, substituting your own S3 bucket and prefix for where your event data will be stored. A Data Catalog database is a logical container that holds the different tables that you can create. The default database name shown here should already exist. If it doesn’t, you can create it or use another database that you’ve already created.

CREATE EXTERNAL TABLE default.kfhconnectblog (
  awsaccountid string,
  agentarn string,
  currentagentsnapshot string,
  eventid string,
  eventtimestamp string,
  eventtype string,
  instancearn string,
  previousagentsnapshot string,
  version string
)
STORED AS parquet
LOCATION 's3://your_bucket/kfhconnectblog/'
TBLPROPERTIES ("parquet.compression"="SNAPPY")

That’s all you have to do to prepare the schema for Kinesis Data Firehose.

2. Define the data streams

Next, you need to define the Kinesis data streams that will be used to stream the Amazon Connect events.  Open the Kinesis Data Streams console and create two streams.  You can configure them with only one shard each because you don’t have a lot of data right now.

3. Define the Kinesis Data Firehose delivery stream for Parquet

Let’s configure the Data Firehose delivery stream using the data stream as the source and Amazon S3 as the output. Start by opening the Kinesis Data Firehose console and creating a new data delivery stream. Give it a name, and associate it with the Kinesis data stream that you created in Step 2.

As shown in the following screenshot, enable Record format conversion (1) and choose Apache Parquet (2). As you can see, Apache ORC is also supported. Scroll down and provide the AWS Glue Data Catalog database name (3) and table names (4) that you created in Step 1. Choose Next.

To make things easier, the output S3 bucket and prefix fields are automatically populated using the values that you defined in the LOCATION parameter of the create table statement from Step 1. Pretty cool. Additionally, you have the option to save the raw events into another location as defined in the Source record S3 backup section. Don’t forget to add a trailing forward slash “ / “ so that Data Firehose creates the date partitions inside that prefix.

On the next page, in the S3 buffer conditions section, there is a note about configuring a large buffer size. The Parquet file format is highly efficient in how it stores and compresses data. Increasing the buffer size allows you to pack more rows into each output file, which is preferred and gives you the most benefit from Parquet.

Compression using Snappy is automatically enabled for both Parquet and ORC. You can modify the compression algorithm by using the Kinesis Data Firehose API and update the OutputFormatConfiguration.

Be sure to also enable Amazon CloudWatch Logs so that you can debug any issues that you might run into.

Lastly, finalize the creation of the Firehose delivery stream, and continue on to the next section.

4. Set up the Amazon Connect contact center

After setting up the Kinesis pipeline, you now need to set up a simple contact center in Amazon Connect. The Getting Started page provides clear instructions on how to set up your environment, acquire a phone number, and create an agent to accept calls.

After setting up the contact center, in the Amazon Connect console, choose your Instance Alias, and then choose Data Streaming. Under Agent Event, choose the Kinesis data stream that you created in Step 2, and then choose Save.

At this point, your pipeline is complete.  Agent events from Amazon Connect are generated as agents go about their day. Events are sent via Kinesis Data Streams to Kinesis Data Firehose, which converts the event data from JSON to Parquet and stores it in S3. Athena and Amazon Redshift Spectrum can simply query the data without any additional work.

So let’s generate some data. Go back into the Administrator console for your Amazon Connect contact center, and create an agent to handle incoming calls. In this example, I creatively named mine Agent One. After it is created, Agent One can get to work and log into their console and set their availability to Available so that they are ready to receive calls.

To make the data a bit more interesting, I also created a second agent, Agent Two. I then made some incoming and outgoing calls and caused some failures to occur, so I now have enough data available to analyze.

5. Analyze the data with Athena

Let’s open the Athena console and run some queries. One thing you’ll notice is that when we created the schema for the dataset, we defined some of the fields as Strings even though in the documentation they were complex structures.  The reason for doing that was simply to show some of the flexibility of Athena to be able to parse JSON data. However, you can define nested structures in your table schema so that Kinesis Data Firehose applies the appropriate schema to the Parquet file.

Let’s run the first query to see which agents have logged into the system.

The query might look complex, but it’s fairly straightforward:

WITH dataset AS (
  SELECT 
    from_iso8601_timestamp(eventtimestamp) AS event_ts,
    eventtype,
    -- CURRENT STATE
    json_extract_scalar(
      currentagentsnapshot,
      '$.agentstatus.name') AS current_status,
    from_iso8601_timestamp(
      json_extract_scalar(
        currentagentsnapshot,
        '$.agentstatus.starttimestamp')) AS current_starttimestamp,
    json_extract_scalar(
      currentagentsnapshot, 
      '$.configuration.firstname') AS current_firstname,
    json_extract_scalar(
      currentagentsnapshot,
      '$.configuration.lastname') AS current_lastname,
    json_extract_scalar(
      currentagentsnapshot, 
      '$.configuration.username') AS current_username,
    json_extract_scalar(
      currentagentsnapshot, 
      '$.configuration.routingprofile.defaultoutboundqueue.name') AS               current_outboundqueue,
    json_extract_scalar(
      currentagentsnapshot, 
      '$.configuration.routingprofile.inboundqueues[0].name') as current_inboundqueue,
    -- PREVIOUS STATE
    json_extract_scalar(
      previousagentsnapshot, 
      '$.agentstatus.name') as prev_status,
    from_iso8601_timestamp(
      json_extract_scalar(
        previousagentsnapshot, 
       '$.agentstatus.starttimestamp')) as prev_starttimestamp,
    json_extract_scalar(
      previousagentsnapshot, 
      '$.configuration.firstname') as prev_firstname,
    json_extract_scalar(
      previousagentsnapshot, 
      '$.configuration.lastname') as prev_lastname,
    json_extract_scalar(
      previousagentsnapshot, 
      '$.configuration.username') as prev_username,
    json_extract_scalar(
      previousagentsnapshot, 
      '$.configuration.routingprofile.defaultoutboundqueue.name') as current_outboundqueue,
    json_extract_scalar(
      previousagentsnapshot, 
      '$.configuration.routingprofile.inboundqueues[0].name') as prev_inboundqueue
  from kfhconnectblog
  where eventtype <> 'HEART_BEAT'
)
SELECT
  current_status as status,
  current_username as username,
  event_ts
FROM dataset
WHERE eventtype = 'LOGIN' AND current_username <> ''
ORDER BY event_ts DESC

The query output looks something like this:

Here is another query that shows the sessions each of the agents engaged with. It tells us where they were incoming or outgoing, if they were completed, and where there were missed or failed calls.

WITH src AS (
  SELECT
     eventid,
     json_extract_scalar(currentagentsnapshot, '$.configuration.username') as username,
     cast(json_extract(currentagentsnapshot, '$.contacts') AS ARRAY(JSON)) as c,
     cast(json_extract(previousagentsnapshot, '$.contacts') AS ARRAY(JSON)) as p
  from kfhconnectblog
),
src2 AS (
  SELECT *
  FROM src CROSS JOIN UNNEST (c, p) AS contacts(c_item, p_item)
),
dataset AS (
SELECT 
  eventid,
  username,
  json_extract_scalar(c_item, '$.contactid') as c_contactid,
  json_extract_scalar(c_item, '$.channel') as c_channel,
  json_extract_scalar(c_item, '$.initiationmethod') as c_direction,
  json_extract_scalar(c_item, '$.queue.name') as c_queue,
  json_extract_scalar(c_item, '$.state') as c_state,
  from_iso8601_timestamp(json_extract_scalar(c_item, '$.statestarttimestamp')) as c_ts,
  
  json_extract_scalar(p_item, '$.contactid') as p_contactid,
  json_extract_scalar(p_item, '$.channel') as p_channel,
  json_extract_scalar(p_item, '$.initiationmethod') as p_direction,
  json_extract_scalar(p_item, '$.queue.name') as p_queue,
  json_extract_scalar(p_item, '$.state') as p_state,
  from_iso8601_timestamp(json_extract_scalar(p_item, '$.statestarttimestamp')) as p_ts
FROM src2
)
SELECT 
  username,
  c_channel as channel,
  c_direction as direction,
  p_state as prev_state,
  c_state as current_state,
  c_ts as current_ts,
  c_contactid as id
FROM dataset
WHERE c_contactid = p_contactid
ORDER BY id DESC, current_ts ASC

The query output looks similar to the following:

6. Analyze the data with Amazon Redshift Spectrum

With Amazon Redshift Spectrum, you can query data directly in S3 using your existing Amazon Redshift data warehouse cluster. Because the data is already in Parquet format, Redshift Spectrum gets the same great benefits that Athena does.

Here is a simple query to show querying the same data from Amazon Redshift. Note that to do this, you need to first create an external schema in Amazon Redshift that points to the AWS Glue Data Catalog.

SELECT 
  eventtype,
  json_extract_path_text(currentagentsnapshot,'agentstatus','name') AS current_status,
  json_extract_path_text(currentagentsnapshot, 'configuration','firstname') AS current_firstname,
  json_extract_path_text(currentagentsnapshot, 'configuration','lastname') AS current_lastname,
  json_extract_path_text(
    currentagentsnapshot,
    'configuration','routingprofile','defaultoutboundqueue','name') AS current_outboundqueue,
FROM default_schema.kfhconnectblog

The following shows the query output:

Summary

In this post, I showed you how to use Kinesis Data Firehose to ingest and convert data to columnar file format, enabling real-time analysis using Athena and Amazon Redshift. This great feature enables a level of optimization in both cost and performance that you need when storing and analyzing large amounts of data. This feature is equally important if you are investing in building data lakes on AWS.

 


Additional Reading

If you found this post useful, be sure to check out Analyzing VPC Flow Logs with Amazon Kinesis Firehose, Amazon Athena, and Amazon QuickSight and Work with partitioned data in AWS Glue.


About the Author

Roy Hasson is a Global Business Development Manager for AWS Analytics. He works with customers around the globe to design solutions to meet their data processing, analytics and business intelligence needs. Roy is big Manchester United fan cheering his team on and hanging out with his family.

 

 

 

Analyze data in Amazon DynamoDB using Amazon SageMaker for real-time prediction

Post Syndicated from YongSeong Lee original https://aws.amazon.com/blogs/big-data/analyze-data-in-amazon-dynamodb-using-amazon-sagemaker-for-real-time-prediction/

Many companies across the globe use Amazon DynamoDB to store and query historical user-interaction data. DynamoDB is a fast NoSQL database used by applications that need consistent, single-digit millisecond latency.

Often, customers want to turn their valuable data in DynamoDB into insights by analyzing a copy of their table stored in Amazon S3. Doing this separates their analytical queries from their low-latency critical paths. This data can be the primary source for understanding customers’ past behavior, predicting future behavior, and generating downstream business value. Customers often turn to DynamoDB because of its great scalability and high availability. After a successful launch, many customers want to use the data in DynamoDB to predict future behaviors or provide personalized recommendations.

DynamoDB is a good fit for low-latency reads and writes, but it’s not practical to scan all data in a DynamoDB database to train a model. In this post, I demonstrate how you can use DynamoDB table data copied to Amazon S3 by AWS Data Pipeline to predict customer behavior. I also demonstrate how you can use this data to provide personalized recommendations for customers using Amazon SageMaker. You can also run ad hoc queries using Amazon Athena against the data. DynamoDB recently released on-demand backups to create full table backups with no performance impact. However, it’s not suitable for our purposes in this post, so I chose AWS Data Pipeline instead to create managed backups are accessible from other services.

To do this, I describe how to read the DynamoDB backup file format in Data Pipeline. I also describe how to convert the objects in S3 to a CSV format that Amazon SageMaker can read. In addition, I show how to schedule regular exports and transformations using Data Pipeline. The sample data used in this post is from Bank Marketing Data Set of UCI.

The solution that I describe provides the following benefits:

  • Separates analytical queries from production traffic on your DynamoDB table, preserving your DynamoDB read capacity units (RCUs) for important production requests
  • Automatically updates your model to get real-time predictions
  • Optimizes for performance (so it doesn’t compete with DynamoDB RCUs after the export) and for cost (using data you already have)
  • Makes it easier for developers of all skill levels to use Amazon SageMaker

All code and data set in this post are available in this .zip file.

Solution architecture

The following diagram shows the overall architecture of the solution.

The steps that data follows through the architecture are as follows:

  1. Data Pipeline regularly copies the full contents of a DynamoDB table as JSON into an S3
  2. Exported JSON files are converted to comma-separated value (CSV) format to use as a data source for Amazon SageMaker.
  3. Amazon SageMaker renews the model artifact and update the endpoint.
  4. The converted CSV is available for ad hoc queries with Amazon Athena.
  5. Data Pipeline controls this flow and repeats the cycle based on the schedule defined by customer requirements.

Building the auto-updating model

This section discusses details about how to read the DynamoDB exported data in Data Pipeline and build automated workflows for real-time prediction with a regularly updated model.

Download sample scripts and data

Before you begin, take the following steps:

  1. Download sample scripts in this .zip file.
  2. Unzip the src.zip file.
  3. Find the automation_script.sh file and edit it for your environment. For example, you need to replace 's3://<your bucket>/<datasource path>/' with your own S3 path to the data source for Amazon ML. In the script, the text enclosed by angle brackets—< and >—should be replaced with your own path.
  4. Upload the json-serde-1.3.6-SNAPSHOT-jar-with-dependencies.jar file to your S3 path so that the ADD jar command in Apache Hive can refer to it.

For this solution, the banking.csv  should be imported into a DynamoDB table.

Export a DynamoDB table

To export the DynamoDB table to S3, open the Data Pipeline console and choose the Export DynamoDB table to S3 template. In this template, Data Pipeline creates an Amazon EMR cluster and performs an export in the EMRActivity activity. Set proper intervals for backups according to your business requirements.

One core node(m3.xlarge) provides the default capacity for the EMR cluster and should be suitable for the solution in this post. Leave the option to resize the cluster before running enabled in the TableBackupActivity activity to let Data Pipeline scale the cluster to match the table size. The process of converting to CSV format and renewing models happens in this EMR cluster.

For a more in-depth look at how to export data from DynamoDB, see Export Data from DynamoDB in the Data Pipeline documentation.

Add the script to an existing pipeline

After you export your DynamoDB table, you add an additional EMR step to EMRActivity by following these steps:

  1. Open the Data Pipeline console and choose the ID for the pipeline that you want to add the script to.
  2. For Actions, choose Edit.
  3. In the editing console, choose the Activities category and add an EMR step using the custom script downloaded in the previous section, as shown below.

Paste the following command into the new step after the data ­­upload step:

s3://#{myDDBRegion}.elasticmapreduce/libs/script-runner/script-runner.jar,s3://<your bucket name>/automation_script.sh,#{output.directoryPath},#{myDDBRegion}

The element #{output.directoryPath} references the S3 path where the data pipeline exports DynamoDB data as JSON. The path should be passed to the script as an argument.

The bash script has two goals, converting data formats and renewing the Amazon SageMaker model. Subsequent sections discuss the contents of the automation script.

Automation script: Convert JSON data to CSV with Hive

We use Apache Hive to transform the data into a new format. The Hive QL script to create an external table and transform the data is included in the custom script that you added to the Data Pipeline definition.

When you run the Hive scripts, do so with the -e option. Also, define the Hive table with the 'org.openx.data.jsonserde.JsonSerDe' row format to parse and read JSON format. The SQL creates a Hive EXTERNAL table, and it reads the DynamoDB backup data on the S3 path passed to it by Data Pipeline.

Note: You should create the table with the “EXTERNAL” keyword to avoid the backup data being accidentally deleted from S3 if you drop the table.

The full automation script for converting follows. Add your own bucket name and data source path in the highlighted areas.

#!/bin/bash
hive -e "
ADD jar s3://<your bucket name>/json-serde-1.3.6-SNAPSHOT-jar-with-dependencies.jar ; 
DROP TABLE IF EXISTS blog_backup_data ;
CREATE EXTERNAL TABLE blog_backup_data (
 customer_id map<string,string>,
 age map<string,string>, job map<string,string>, 
 marital map<string,string>,education map<string,string>, 
 default map<string,string>, housing map<string,string>,
 loan map<string,string>, contact map<string,string>, 
 month map<string,string>, day_of_week map<string,string>, 
 duration map<string,string>, campaign map<string,string>,
 pdays map<string,string>, previous map<string,string>, 
 poutcome map<string,string>, emp_var_rate map<string,string>, 
 cons_price_idx map<string,string>, cons_conf_idx map<string,string>,
 euribor3m map<string,string>, nr_employed map<string,string>, 
 y map<string,string> ) 
ROW FORMAT SERDE 'org.openx.data.jsonserde.JsonSerDe' 
LOCATION '$1/';

INSERT OVERWRITE DIRECTORY 's3://<your bucket name>/<datasource path>/' 
SELECT concat( customer_id['s'],',', 
 age['n'],',', job['s'],',', 
 marital['s'],',', education['s'],',', default['s'],',', 
 housing['s'],',', loan['s'],',', contact['s'],',', 
 month['s'],',', day_of_week['s'],',', duration['n'],',', 
 campaign['n'],',',pdays['n'],',',previous['n'],',', 
 poutcome['s'],',', emp_var_rate['n'],',', cons_price_idx['n'],',',
 cons_conf_idx['n'],',', euribor3m['n'],',', nr_employed['n'],',', y['n'] ) 
FROM blog_backup_data
WHERE customer_id['s'] > 0 ; 

After creating an external table, you need to read data. You then use the INSERT OVERWRITE DIRECTORY ~ SELECT command to write CSV data to the S3 path that you designated as the data source for Amazon SageMaker.

Depending on your requirements, you can eliminate or process the columns in the SELECT clause in this step to optimize data analysis. For example, you might remove some columns that have unpredictable correlations with the target value because keeping the wrong columns might expose your model to “overfitting” during the training. In this post, customer_id  columns is removed. Overfitting can make your prediction weak. More information about overfitting can be found in the topic Model Fit: Underfitting vs. Overfitting in the Amazon ML documentation.

Automation script: Renew the Amazon SageMaker model

After the CSV data is replaced and ready to use, create a new model artifact for Amazon SageMaker with the updated dataset on S3.  For renewing model artifact, you must create a new training job.  Training jobs can be run using the AWS SDK ( for example, Amazon SageMaker boto3 ) or the Amazon SageMaker Python SDK that can be installed with “pip install sagemaker” command as well as the AWS CLI for Amazon SageMaker described in this post.

In addition, consider how to smoothly renew your existing model without service impact, because your model is called by applications in real time. To do this, you need to create a new endpoint configuration first and update a current endpoint with the endpoint configuration that is just created.

#!/bin/bash
## Define variable 
REGION=$2
DTTIME=`date +%Y-%m-%d-%H-%M-%S`
ROLE="<your AmazonSageMaker-ExecutionRole>" 


# Select containers image based on region.  
case "$REGION" in
"us-west-2" )
    IMAGE="174872318107.dkr.ecr.us-west-2.amazonaws.com/linear-learner:latest"
    ;;
"us-east-1" )
    IMAGE="382416733822.dkr.ecr.us-east-1.amazonaws.com/linear-learner:latest" 
    ;;
"us-east-2" )
    IMAGE="404615174143.dkr.ecr.us-east-2.amazonaws.com/linear-learner:latest" 
    ;;
"eu-west-1" )
    IMAGE="438346466558.dkr.ecr.eu-west-1.amazonaws.com/linear-learner:latest" 
    ;;
 *)
    echo "Invalid Region Name"
    exit 1 ;  
esac

# Start training job and creating model artifact 
TRAINING_JOB_NAME=TRAIN-${DTTIME} 
S3OUTPUT="s3://<your bucket name>/model/" 
INSTANCETYPE="ml.m4.xlarge"
INSTANCECOUNT=1
VOLUMESIZE=5 
aws sagemaker create-training-job --training-job-name ${TRAINING_JOB_NAME} --region ${REGION}  --algorithm-specification TrainingImage=${IMAGE},TrainingInputMode=File --role-arn ${ROLE}  --input-data-config '[{ "ChannelName": "train", "DataSource": { "S3DataSource": { "S3DataType": "S3Prefix", "S3Uri": "s3://<your bucket name>/<datasource path>/", "S3DataDistributionType": "FullyReplicated" } }, "ContentType": "text/csv", "CompressionType": "None" , "RecordWrapperType": "None"  }]'  --output-data-config S3OutputPath=${S3OUTPUT} --resource-config  InstanceType=${INSTANCETYPE},InstanceCount=${INSTANCECOUNT},VolumeSizeInGB=${VOLUMESIZE} --stopping-condition MaxRuntimeInSeconds=120 --hyper-parameters feature_dim=20,predictor_type=binary_classifier  

# Wait until job completed 
aws sagemaker wait training-job-completed-or-stopped --training-job-name ${TRAINING_JOB_NAME}  --region ${REGION}

# Get newly created model artifact and create model
MODELARTIFACT=`aws sagemaker describe-training-job --training-job-name ${TRAINING_JOB_NAME} --region ${REGION}  --query 'ModelArtifacts.S3ModelArtifacts' --output text `
MODELNAME=MODEL-${DTTIME}
aws sagemaker create-model --region ${REGION} --model-name ${MODELNAME}  --primary-container Image=${IMAGE},ModelDataUrl=${MODELARTIFACT}  --execution-role-arn ${ROLE}

# create a new endpoint configuration 
CONFIGNAME=CONFIG-${DTTIME}
aws sagemaker  create-endpoint-config --region ${REGION} --endpoint-config-name ${CONFIGNAME}  --production-variants  VariantName=Users,ModelName=${MODELNAME},InitialInstanceCount=1,InstanceType=ml.m4.xlarge

# create or update the endpoint
STATUS=`aws sagemaker describe-endpoint --endpoint-name  ServiceEndpoint --query 'EndpointStatus' --output text --region ${REGION} `
if [[ $STATUS -ne "InService" ]] ;
then
    aws sagemaker  create-endpoint --endpoint-name  ServiceEndpoint  --endpoint-config-name ${CONFIGNAME} --region ${REGION}    
else
    aws sagemaker  update-endpoint --endpoint-name  ServiceEndpoint  --endpoint-config-name ${CONFIGNAME} --region ${REGION}
fi

Grant permission

Before you execute the script, you must grant proper permission to Data Pipeline. Data Pipeline uses the DataPipelineDefaultResourceRole role by default. I added the following policy to DataPipelineDefaultResourceRole to allow Data Pipeline to create, delete, and update the Amazon SageMaker model and data source in the script.

{
 "Version": "2012-10-17",
 "Statement": [
 {
 "Effect": "Allow",
 "Action": [
 "sagemaker:CreateTrainingJob",
 "sagemaker:DescribeTrainingJob",
 "sagemaker:CreateModel",
 "sagemaker:CreateEndpointConfig",
 "sagemaker:DescribeEndpoint",
 "sagemaker:CreateEndpoint",
 "sagemaker:UpdateEndpoint",
 "iam:PassRole"
 ],
 "Resource": "*"
 }
 ]
}

Use real-time prediction

After you deploy a model into production using Amazon SageMaker hosting services, your client applications use this API to get inferences from the model hosted at the specified endpoint. This approach is useful for interactive web, mobile, or desktop applications.

Following, I provide a simple Python code example that queries against Amazon SageMaker endpoint URL with its name (“ServiceEndpoint”) and then uses them for real-time prediction.

=== Python sample for real-time prediction ===

#!/usr/bin/env python
import boto3
import json 

client = boto3.client('sagemaker-runtime', region_name ='<your region>' )
new_customer_info = '34,10,2,4,1,2,1,1,6,3,190,1,3,4,3,-1.7,94.055,-39.8,0.715,4991.6'
response = client.invoke_endpoint(
    EndpointName='ServiceEndpoint',
    Body=new_customer_info, 
    ContentType='text/csv'
)
result = json.loads(response['Body'].read().decode())
print(result)
--- output(response) ---
{u'predictions': [{u'score': 0.7528127431869507, u'predicted_label': 1.0}]}

Solution summary

The solution takes the following steps:

  1. Data Pipeline exports DynamoDB table data into S3. The original JSON data should be kept to recover the table in the rare event that this is needed. Data Pipeline then converts JSON to CSV so that Amazon SageMaker can read the data.Note: You should select only meaningful attributes when you convert CSV. For example, if you judge that the “campaign” attribute is not correlated, you can eliminate this attribute from the CSV.
  2. Train the Amazon SageMaker model with the new data source.
  3. When a new customer comes to your site, you can judge how likely it is for this customer to subscribe to your new product based on “predictedScores” provided by Amazon SageMaker.
  4. If the new user subscribes your new product, your application must update the attribute “y” to the value 1 (for yes). This updated data is provided for the next model renewal as a new data source. It serves to improve the accuracy of your prediction. With each new entry, your application can become smarter and deliver better predictions.

Running ad hoc queries using Amazon Athena

Amazon Athena is a serverless query service that makes it easy to analyze large amounts of data stored in Amazon S3 using standard SQL. Athena is useful for examining data and collecting statistics or informative summaries about data. You can also use the powerful analytic functions of Presto, as described in the topic Aggregate Functions of Presto in the Presto documentation.

With the Data Pipeline scheduled activity, recent CSV data is always located in S3 so that you can run ad hoc queries against the data using Amazon Athena. I show this with example SQL statements following. For an in-depth description of this process, see the post Interactive SQL Queries for Data in Amazon S3 on the AWS News Blog. 

Creating an Amazon Athena table and running it

Simply, you can create an EXTERNAL table for the CSV data on S3 in Amazon Athena Management Console.

=== Table Creation ===
CREATE EXTERNAL TABLE datasource (
 age int, 
 job string, 
 marital string , 
 education string, 
 default string, 
 housing string, 
 loan string, 
 contact string, 
 month string, 
 day_of_week string, 
 duration int, 
 campaign int, 
 pdays int , 
 previous int , 
 poutcome string, 
 emp_var_rate double, 
 cons_price_idx double,
 cons_conf_idx double, 
 euribor3m double, 
 nr_employed double, 
 y int 
)
ROW FORMAT DELIMITED 
FIELDS TERMINATED BY ',' ESCAPED BY '\\' LINES TERMINATED BY '\n' 
LOCATION 's3://<your bucket name>/<datasource path>/';

The following query calculates the correlation coefficient between the target attribute and other attributes using Amazon Athena.

=== Sample Query ===

SELECT corr(age,y) AS correlation_age_and_target, 
 corr(duration,y) AS correlation_duration_and_target, 
 corr(campaign,y) AS correlation_campaign_and_target,
 corr(contact,y) AS correlation_contact_and_target
FROM ( SELECT age , duration , campaign , y , 
 CASE WHEN contact = 'telephone' THEN 1 ELSE 0 END AS contact 
 FROM datasource 
 ) datasource ;

Conclusion

In this post, I introduce an example of how to analyze data in DynamoDB by using table data in Amazon S3 to optimize DynamoDB table read capacity. You can then use the analyzed data as a new data source to train an Amazon SageMaker model for accurate real-time prediction. In addition, you can run ad hoc queries against the data on S3 using Amazon Athena. I also present how to automate these procedures by using Data Pipeline.

You can adapt this example to your specific use case at hand, and hopefully this post helps you accelerate your development. You can find more examples and use cases for Amazon SageMaker in the video AWS 2017: Introducing Amazon SageMaker on the AWS website.

 


Additional Reading

If you found this post useful, be sure to check out Serving Real-Time Machine Learning Predictions on Amazon EMR and Analyzing Data in S3 using Amazon Athena.

 


About the Author

Yong Seong Lee is a Cloud Support Engineer for AWS Big Data Services. He is interested in every technology related to data/databases and helping customers who have difficulties in using AWS services. His motto is “Enjoy life, be curious and have maximum experience.”

 

 

Hard Drive Stats for Q1 2018

Post Syndicated from Andy Klein original https://www.backblaze.com/blog/hard-drive-stats-for-q1-2018/

Backblaze Drive Stats Q1 2018

As of March 31, 2018 we had 100,110 spinning hard drives. Of that number, there were 1,922 boot drives and 98,188 data drives. This review looks at the quarterly and lifetime statistics for the data drive models in operation in our data centers. We’ll also take a look at why we are collecting and reporting 10 new SMART attributes and take a sneak peak at some 8 TB Toshiba drives. Along the way, we’ll share observations and insights on the data presented and we look forward to you doing the same in the comments.

Background

Since April 2013, Backblaze has recorded and saved daily hard drive statistics from the drives in our data centers. Each entry consists of the date, manufacturer, model, serial number, status (operational or failed), and all of the SMART attributes reported by that drive. Currently there are about 97 million entries totaling 26 GB of data. You can download this data from our website if you want to do your own research, but for starters here’s what we found.

Hard Drive Reliability Statistics for Q1 2018

At the end of Q1 2018 Backblaze was monitoring 98,188 hard drives used to store data. For our evaluation below we remove from consideration those drives which were used for testing purposes and those drive models for which we did not have at least 45 drives. This leaves us with 98,046 hard drives. The table below covers just Q1 2018.

Q1 2018 Hard Drive Failure Rates

Notes and Observations

If a drive model has a failure rate of 0%, it only means there were no drive failures of that model during Q1 2018.

The overall Annualized Failure Rate (AFR) for Q1 is just 1.2%, well below the Q4 2017 AFR of 1.65%. Remember that quarterly failure rates can be volatile, especially for models that have a small number of drives and/or a small number of Drive Days.

There were 142 drives (98,188 minus 98,046) that were not included in the list above because we did not have at least 45 of a given drive model. We use 45 drives of the same model as the minimum number when we report quarterly, yearly, and lifetime drive statistics.

Welcome Toshiba 8TB drives, almost…

We mentioned Toshiba 8 TB drives in the first paragraph, but they don’t show up in the Q1 Stats chart. What gives? We only had 20 of the Toshiba 8 TB drives in operation in Q1, so they were excluded from the chart. Why do we have only 20 drives? When we test out a new drive model we start with the “tome test” and it takes 20 drives to fill one tome. A tome is the same drive model in the same logical position in each of the 20 Storage Pods that make up a Backblaze Vault. There are 60 tomes in each vault.

In this test, we created a Backblaze Vault of 8 TB drives, with 59 of the tomes being Seagate 8 TB drives and 1 tome being the Toshiba drives. Then we monitored the performance of the vault and its member tomes to see if, in this case, the Toshiba drives performed as expected.

Q1 2018 Hard Drive Failure Rate — Toshiba 8TB

So far the Toshiba drive is performing fine, but they have been in place for only 20 days. Next up is the “pod test” where we fill a Storage Pod with Toshiba drives and integrate it into a Backblaze Vault comprised of like-sized drives. We hope to have a better look at the Toshiba 8 TB drives in our Q2 report — stay tuned.

Lifetime Hard Drive Reliability Statistics

While the quarterly chart presented earlier gets a lot of interest, the real test of any drive model is over time. Below is the lifetime failure rate chart for all the hard drive models which have 45 or more drives in operation as of March 31st, 2018. For each model, we compute their reliability starting from when they were first installed.

Lifetime Hard Drive Failure Rates

Notes and Observations

The failure rates of all of the larger drives (8-, 10- and 12 TB) are very good, 1.2% AFR (Annualized Failure Rate) or less. Many of these drives were deployed in the last year, so there is some volatility in the data, but you can use the Confidence Interval to get a sense of the failure percentage range.

The overall failure rate of 1.84% is the lowest we have ever achieved, besting the previous low of 2.00% from the end of 2017.

Our regular readers and drive stats wonks may have noticed a sizable jump in the number of HGST 8 TB drives (model: HUH728080ALE600), from 45 last quarter to 1,045 this quarter. As the 10 TB and 12 TB drives become more available, the price per terabyte of the 8 TB drives has gone down. This presented an opportunity to purchase the HGST drives at a price in line with our budget.

We purchased and placed into service the 45 original HGST 8 TB drives in Q2 of 2015. They were our first Helium-filled drives and our only ones until the 10 TB and 12 TB Seagate drives arrived in Q3 2017. We’ll take a first look into whether or not Helium makes a difference in drive failure rates in an upcoming blog post.

New SMART Attributes

If you have previously worked with the hard drive stats data or plan to, you’ll notice that we added 10 more columns of data starting in 2018. There are 5 new SMART attributes we are tracking each with a raw and normalized value:

  • 177 – Wear Range Delta
  • 179 – Used Reserved Block Count Total
  • 181- Program Fail Count Total or Non-4K Aligned Access Count
  • 182 – Erase Fail Count
  • 235 – Good Block Count AND System(Free) Block Count

The 5 values are all related to SSD drives.

Yes, SSD drives, but before you jump to any conclusions, we used 10 Samsung 850 EVO SSDs as boot drives for a period of time in Q1. This was an experiment to see if we could reduce boot up time for the Storage Pods. In our case, the improved boot up speed wasn’t worth the SSD cost, but it did add 10 new columns to the hard drive stats data.

Speaking of hard drive stats data, the complete data set used to create the information used in this review is available on our Hard Drive Test Data page. You can download and use this data for free for your own purpose, all we ask are three things: 1) you cite Backblaze as the source if you use the data, 2) you accept that you are solely responsible for how you use the data, and 3) you do not sell this data to anyone. It is free.

If you just want the summarized data used to create the tables and charts in this blog post, you can download the ZIP file containing the MS Excel spreadsheet.

Good luck and let us know if you find anything interesting.

[Ed: 5/1/2018 – Updated Lifetime chart to fix error in confidence interval for HGST 4TB drive, model: HDS5C4040ALE630]

The post Hard Drive Stats for Q1 2018 appeared first on Backblaze Blog | Cloud Storage & Cloud Backup.

Congratulations to Oracle on MySQL 8.0

Post Syndicated from Michael "Monty" Widenius original http://monty-says.blogspot.com/2018/04/congratulations-to-oracle-on-mysql-80.html

Last week, Oracle announced the general availability of MySQL 8.0. This is good news for database users, as it means Oracle is still developing MySQL.

I decide to celebrate the event by doing a quick test of MySQL 8.0. Here follows a step-by-step description of my first experience with MySQL 8.0.
Note that I did the following without reading the release notes, as is what I have done with every MySQL / MariaDB release up to date; In this case it was not the right thing to do.

I pulled MySQL 8.0 from [email protected]:mysql/mysql-server.git
I was pleasantly surprised that ‘cmake . ; make‘ worked without without any compiler warnings! I even checked the used compiler options and noticed that MySQL was compiled with -Wall + several other warning flags. Good job MySQL team!

I did have a little trouble finding the mysqld binary as Oracle had moved it to ‘runtime_output_directory’; Unexpected, but no big thing.

Now it’s was time to install MySQL 8.0.

I did know that MySQL 8.0 has removed mysql_install_db, so I had to use the mysqld binary directly to install the default databases:
(I have specified datadir=/my/data3 in the /tmp/my.cnf file)

> cd runtime_output_directory
> mkdir /my/data3
> ./mysqld –defaults-file=/tmp/my.cnf –install

2018-04-22T12:38:18.332967Z 1 [ERROR] [MY-011011] [Server] Failed to find valid data directory.
2018-04-22T12:38:18.333109Z 0 [ERROR] [MY-010020] [Server] Data Dictionary initialization failed.
2018-04-22T12:38:18.333135Z 0 [ERROR] [MY-010119] [Server] Aborting

A quick look in mysqld –help –verbose output showed that the right command option is –-initialize. My bad, lets try again,

> ./mysqld –defaults-file=/tmp/my.cnf –initialize

2018-04-22T12:39:31.910509Z 0 [ERROR] [MY-010457] [Server] –initialize specified but the data directory has files in it. Aborting.
2018-04-22T12:39:31.910578Z 0 [ERROR] [MY-010119] [Server] Aborting

Now I used the right options, but still didn’t work.
I took a quick look around:

> ls /my/data3/
binlog.index

So even if the mysqld noticed that the data3 directory was wrong, it still wrote things into it.  This even if I didn’t have –log-binlog enabled in the my.cnf file. Strange, but easy to fix:

> rm /my/data3/binlog.index
> ./mysqld –defaults-file=/tmp/my.cnf –initialize

2018-04-22T12:40:45.633637Z 0 [ERROR] [MY-011071] [Server] unknown variable ‘max-tmp-tables=100’
2018-04-22T12:40:45.633657Z 0 [Warning] [MY-010952] [Server] The privilege system failed to initialize correctly. If you have upgraded your server, make sure you’re executing mysql_upgrade to correct the issue.
2018-04-22T12:40:45.633663Z 0 [ERROR] [MY-010119] [Server] Aborting

The warning about the privilege system confused me a bit, but I ignored it for the time being and removed from my configuration files the variables that MySQL 8.0 doesn’t support anymore. I couldn’t find a list of the removed variables anywhere so this was done with the trial and error method.

> ./mysqld –defaults-file=/tmp/my.cnf

2018-04-22T12:42:56.626583Z 0 [ERROR] [MY-010735] [Server] Can’t open the mysql.plugin table. Please run mysql_upgrade to create it.
2018-04-22T12:42:56.827685Z 0 [Warning] [MY-010015] [Repl] Gtid table is not ready to be used. Table ‘mysql.gtid_executed’ cannot be opened.
2018-04-22T12:42:56.838501Z 0 [Warning] [MY-010068] [Server] CA certificate ca.pem is self signed.
2018-04-22T12:42:56.848375Z 0 [Warning] [MY-010441] [Server] Failed to open optimizer cost constant tables
2018-04-22T12:42:56.848863Z 0 [ERROR] [MY-013129] [Server] A message intended for a client cannot be sent there as no client-session is attached. Therefore, we’re sending the information to the error-log instead: MY-001146 – Table ‘mysql.component’ doesn’t exist
2018-04-22T12:42:56.848916Z 0 [Warning] [MY-013129] [Server] A message intended for a client cannot be sent there as no client-session is attached. Therefore, we’re sending the information to the error-log instead: MY-003543 – The mysql.component table is missing or has an incorrect definition.
….
2018-04-22T12:42:56.854141Z 0 [System] [MY-010931] [Server] /home/my/mysql-8.0/runtime_output_directory/mysqld: ready for connections. Version: ‘8.0.11’ socket: ‘/tmp/mysql.sock’ port: 3306 Source distribution.

I figured out that if there is a single wrong variable in the configuration file, running mysqld –initialize will leave the database in an inconsistent state. NOT GOOD! I am happy I didn’t try this in a production system!

Time to start over from the beginning:

> rm -r /my/data3/*
> ./mysqld –defaults-file=/tmp/my.cnf –initialize

2018-04-22T12:44:45.548960Z 5 [Note] [MY-010454] [Server] A temporary password is generated for [email protected]: px)NaaSp?6um
2018-04-22T12:44:51.221751Z 0 [System] [MY-013170] [Server] /home/my/mysql-8.0/runtime_output_directory/mysqld (mysqld 8.0.11) initializing of server has completed

Success!

I wonder why the temporary password is so complex; It could easily have been something that one could easily remember without decreasing security, it’s temporary after all. No big deal, one can always paste it from the logs. (Side note: MariaDB uses socket authentication on many system and thus doesn’t need temporary installation passwords).

Now lets start the MySQL server for real to do some testing:

> ./mysqld –defaults-file=/tmp/my.cnf

2018-04-22T12:45:43.683484Z 0 [System] [MY-010931] [Server] /home/my/mysql-8.0/runtime_output_directory/mysqld: ready for connections. Version: ‘8.0.11’ socket: ‘/tmp/mysql.sock’ port: 3306 Source distribution.

And the lets start the client:

> ./client/mysql –socket=/tmp/mysql.sock –user=root –password=”px)NaaSp?6um”
ERROR 2059 (HY000): Plugin caching_sha2_password could not be loaded: /usr/local/mysql/lib/plugin/caching_sha2_password.so: cannot open shared object file: No such file or directory

Apparently MySQL 8.0 doesn’t work with old MySQL / MariaDB clients by default 🙁

I was testing this in a system with MariaDB installed, like all modern Linux system today, and didn’t want to use the MySQL clients or libraries.

I decided to try to fix this by changing the authentication to the native (original) MySQL authentication method.

> mysqld –skip-grant-tables

> ./client/mysql –socket=/tmp/mysql.sock –user=root
ERROR 1045 (28000): Access denied for user ‘root’@’localhost’ (using password: NO)

Apparently –skip-grant-tables is not good enough anymore. Let’s try again with:

> mysqld –skip-grant-tables –default_authentication_plugin=mysql_native_password

> ./client/mysql –socket=/tmp/mysql.sock –user=root mysql
Welcome to the MariaDB monitor. Commands end with ; or \g.
Your MySQL connection id is 7
Server version: 8.0.11 Source distribution

Great, we are getting somewhere, now lets fix “root”  to work with the old authenticaion:

MySQL [mysql]> update mysql.user set plugin=”mysql_native_password”,authentication_string=password(“test”) where user=”root”;
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ‘(“test”) where user=”root”‘ at line 1

A quick look in the MySQL 8.0 release notes told me that the PASSWORD() function is removed in 8.0. Why???? I don’t know how one in MySQL 8.0 is supposed to generate passwords compatible with old installations of MySQL. One could of course start an old MySQL or MariaDB version, execute the password() function and copy the result.

I decided to fix this the easy way and use an empty password:

(Update:: I later discovered that the right way would have been to use: FLUSH PRIVILEGES;  ALTER USER’ root’@’localhost’ identified by ‘test’  ; I however dislike this syntax as it has the password in clear text which is easy to grab and the command can’t be used to easily update the mysql.user table. One must also disable the –skip-grant mode to do use this)

MySQL [mysql]> update mysql.user set plugin=”mysql_native_password”,authentication_string=”” where user=”root”;
Query OK, 1 row affected (0.077 sec)
Rows matched: 1 Changed: 1 Warnings: 0
 
I restarted mysqld:
> mysqld –default_authentication_plugin=mysql_native_password

> ./client/mysql –user=root –password=”” mysql
ERROR 1862 (HY000): Your password has expired. To log in you must change it using a client that supports expired passwords.

Ouch, forgot that. Lets try again:

> mysqld –skip-grant-tables –default_authentication_plugin=mysql_native_password

> ./client/mysql –user=root –password=”” mysql
MySQL [mysql]> update mysql.user set password_expired=”N” where user=”root”;

Now restart and test worked:

> ./mysqld –default_authentication_plugin=mysql_native_password

>./client/mysql –user=root –password=”” mysql

Finally I had a working account that I can use to create other users!

When looking at mysqld –help –verbose again. I noticed the option:

–initialize-insecure
Create the default database and exit. Create a super user
with empty password.

I decided to check if this would have made things easier:

> rm -r /my/data3/*
> ./mysqld –defaults-file=/tmp/my.cnf –initialize-insecure

2018-04-22T13:18:06.629548Z 5 [Warning] [MY-010453] [Server] [email protected] is created with an empty password ! Please consider switching off the –initialize-insecure option.

Hm. Don’t understand the warning as–initialize-insecure is not an option that one would use more than one time and thus nothing one would ‘switch off’.

> ./mysqld –defaults-file=/tmp/my.cnf

> ./client/mysql –user=root –password=”” mysql
ERROR 2059 (HY000): Plugin caching_sha2_password could not be loaded: /usr/local/mysql/lib/plugin/caching_sha2_password.so: cannot open shared object file: No such file or directory

Back to the beginning 🙁

To get things to work with old clients, one has to initialize the database with:
> ./mysqld –defaults-file=/tmp/my.cnf –initialize-insecure –default_authentication_plugin=mysql_native_password

Now I finally had MySQL 8.0 up and running and thought I would take it up for a spin by running the “standard” MySQL/MariaDB sql-bench test suite. This was removed in MySQL 5.7, but as I happened to have MariaDB 10.3 installed, I decided to run it from there.

sql-bench is a single threaded benchmark that measures the “raw” speed for some common operations. It gives you the ‘maximum’ performance for a single query. Its different from other benchmarks that measures the maximum throughput when you have a lot of users, but sql-bench still tells you a lot about what kind of performance to expect from the database.

I tried first to be clever and create the “test” database, that I needed for sql-bench, with
> mkdir /my/data3/test

but when I tried to run the benchmark, MySQL 8.0 complained that the test database didn’t exist.

MySQL 8.0 has gone away from the original concept of MySQL where the user can easily
create directories and copy databases into the database directory. This may have serious
implication for anyone doing backup of databases and/or trying to restore a backup with normal OS commands.

I created the ‘test’ database with mysqladmin and then tried to run sql-bench:

> ./run-all-tests –user=root

The first run failed in test-ATIS:

Can’t execute command ‘create table class_of_service (class_code char(2) NOT NULL,rank tinyint(2) NOT NULL,class_description char(80) NOT NULL,PRIMARY KEY (class_code))’
Error: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ‘rank tinyint(2) NOT NULL,class_description char(80) NOT NULL,PRIMARY KEY (class_’ at line 1

This happened because ‘rank‘ is now a reserved word in MySQL 8.0. This is also reserved in ANSI SQL, but I don’t know of any other database that has failed to run test-ATIS before. I have in the past run it against Oracle, PostgreSQL, Mimer, MSSQL etc without any problems.

MariaDB also has ‘rank’ as a keyword in 10.2 and 10.3 but one can still use it as an identifier.

I fixed test-ATIS and then managed to run all tests on MySQL 8.0.

I did run the test both with MySQL 8.0 and MariaDB 10.3 with the InnoDB storage engine and by having identical values for all InnoDB variables, table-definition-cache and table-open-cache. I turned off performance schema for both databases. All test are run with a user with an empty password (to keep things comparable and because it’s was too complex to generate a password in MySQL 8.0)

The result are as follows
Results per test in seconds:

Operation         |MariaDB|MySQL-8|

———————————–
ATIS              | 153.00| 228.00|
alter-table       |  92.00| 792.00|
big-tables        | 990.00|2079.00|
connect           | 186.00| 227.00|
create            | 575.00|4465.00|
insert            |4552.00|8458.00|
select            | 333.00| 412.00|
table-elimination |1900.00|3916.00|
wisconsin         | 272.00| 590.00|
———————————–

This is of course just a first view of the performance of MySQL 8.0 in a single user environment. Some reflections about the results:

  • Alter-table test is slower (as expected) in 8.0 as some of the alter tests benefits of the instant add column in MariaDB 10.3.
  • connect test is also better for MariaDB as we put a lot of efforts to speed this up in MariaDB 10.2
  • table-elimination shows an optimization in MariaDB for the  Anchor table model, which MySQL doesn’t have.
  • CREATE and DROP TABLE is almost 8 times slower in MySQL 8.0 than in MariaDB 10.3. I assume this is the cost of ‘atomic DDL’. This may also cause performance problems for any thread using the data dictionary when another thread is creating/dropping tables.
  • When looking at the individual test results, MySQL 8.0 was slower in almost every test, in many significantly slower.
  • The only test where MySQL was faster was “update_with_key_prefix”. I checked this and noticed that there was a bug in the test and the columns was updated to it’s original value (which should be instant with any storage engine). This is an old bug that MySQL has found and fixed and that we have not been aware of in the test or in MariaDB.
  • While writing this, I noticed that MySQL 8.0 is now using utf8mb4 as the default character set instead of latin1. This may affect some of the benchmarks slightly (not much as most tests works with numbers and Oracle claims that utf8mb4 is only 20% slower than latin1), but needs to be verified.
  • Oracle claims that MySQL 8.0 is much faster on multi user benchmarks. The above test indicates that they may have done this by sacrificing single user performance.
  •  We need to do more and many different benchmarks to better understand exactly what is going on. Stay tuned!

Short summary of my first run with MySQL 8.0:

  • Using the new caching_sha2_password authentication as default for new installation is likely to cause a lot of problems for users. No old application will be able to use MySQL 8.0, installed with default options, without moving to MySQL’s client libraries. While working on this blog I saw MySQL users complain on IRC that not even MySQL Workbench can authenticate with MySQL 8.0. This is the first time in MySQL’s history where such an incompatible change has ever been done!
  • Atomic DDL is a good thing (We plan to have this in MariaDB 10.4), but it should not have such a drastic impact on performance. I am also a bit skeptical of MySQL 8.0 having just one copy of the data dictionary as if this gets corrupted you will lose all your data. (Single point of failure)
  • MySQL 8.0 has several new reserved words and has removed a lot of variables, which makes upgrades hard. Before upgrading to MySQL 8.0 one has to check all one’s databases and applications to ensure that there are no conflicts.
  • As my test above shows, if you have a single deprecated variable in your configuration files, the installation of MySQL will abort and can leave the database in inconsistent state. I did of course my tests by installing into an empty data dictionary, but one can assume that some of the problems may also happen when upgrading an old installation.

Conclusions:
In many ways, MySQL 8.0 has caught up with some earlier versions of MariaDB. For instance, in MariaDB 10.0, we introduced roles (four years ago). In MariaDB 10.1, we introduced encrypted redo/undo logs (three years ago). In MariaDB 10.2, we introduced window functions and CTEs (a year ago). However, some catch-up of MariaDB Server 10.2 features still remains for MySQL (such as check constraints, binlog compression, and log-based rollback).

MySQL 8.0 has a few new interesting features (mostly Atomic DDL and JSON TABLE functions), but at the same time MySQL has strayed away from some of the fundamental corner stone principles of MySQL:

From the start of the first version of MySQL in 1995, all development has been focused around 3 core principles:

  • Ease of use
  • Performance
  • Stability

With MySQL 8.0, Oracle has sacrifices 2 of 3 of these.

In addition (as part of ease of use), while I was working on MySQL, we did our best to ensure that the following should hold:

  • Upgrades should be trivial
  • Things should be kept compatible, if possible (don’t remove features/options/functions that are used)
  • Minimize reserved words, don’t remove server variables
  • One should be able to use normal OS commands to create and drop databases, copy and move tables around within the same system or between different systems. With 8.0 and data dictionary taking backups of specific tables will be hard, even if the server is not running.
  • mysqldump should always be usable backups and to move to new releases
  • Old clients and application should be able to use ‘any’ MySQL server version unchanged. (Some Oracle client libraries, like C++, by default only supports the new X protocol and can thus not be used with older MySQL or any MariaDB version)

We plan to add a data dictionary to MariaDB 10.4 or MariaDB 10.5, but in a way to not sacrifice any of the above principles!

The competition between MySQL and MariaDB is not just about a tactical arms race on features. It’s about design philosophy, or strategic vision, if you will.

This shows in two main ways: our respective view of the Storage Engine structure, and of the top-level direction of the roadmap.

On the Storage Engine side, MySQL is converging on InnoDB, even for clustering and partitioning. In doing so, they are abandoning the advantages of multiple ways of storing data. By contrast, MariaDB sees lots of value in the Storage Engine architecture: MariaDB Server 10.3 will see the general availability of MyRocks (for write-intensive workloads) and Spider (for scalable workloads). On top of that, we have ColumnStore for analytical workloads. One can use the CONNECT engine to join with other databases. The use of different storage engines for different workloads and different hardware is a competitive differentiator, now more than ever.

On the roadmap side, MySQL is carefully steering clear of features that close the gap between MySQL and Oracle. MariaDB has no such constraints. With MariaDB 10.3, we are introducing PL/SQL compatibility (Oracle’s stored procedures) and AS OF (built-in system versioned tables with point-in-time querying). For both of those features, MariaDB is the first Open Source database doing so. I don’t except Oracle to provide any of the above features in MySQL!

Also on the roadmap side, MySQL is not working with the ecosystem in extending the functionality. In 2017, MariaDB accepted more code contributions in one year, than MySQL has done during its entire lifetime, and the rate is increasing!

I am sure that the experience I had with testing MySQL 8.0 would have been significantly better if MySQL would have an open development model where the community could easily participate in developing and testing MySQL continuously. Most of the confusing error messages and strange behavior would have been found and fixed long before the GA release.

Before upgrading to MySQL 8.0 please read https://dev.mysql.com/doc/refman/8.0/en/upgrading-from-previous-series.html to see what problems you can run into! Don’t expect that old installations or applications will work out of the box without testing as a lot of features and options has been removed (query cache, partition of myisam tables etc)! You probably also have to revise your backup methods, especially if you want to ever restore just a few tables. (With 8.0, I don’t know how this can be easily done).

According to the MySQL 8.0 release notes, one can’t use mysqldump to copy a database to MySQL 8.0. One has to first to move to a MySQL 5.7 GA version (with mysqldump, as recommended by Oracle) and then to MySQL 8.0 with in-place update. I assume this means that all old mysqldump backups are useless for MySQL 8.0?

MySQL 8.0 seams to be a one way street to an unknown future. Up to MySQL 5.7 it has been trivial to move to MariaDB and one could always move back to MySQL with mysqldump. All MySQL client libraries has worked with MariaDB and all MariaDB client libraries has worked with MySQL. With MySQL 8.0 this has changed in the wrong direction.

As long as you are using MySQL 5.7 and below you have choices for your future, after MySQL 8.0 you have very little choice. But don’t despair, as MariaDB will always be able to load a mysqldump file and it’s very easy to upgrade your old MySQL installation to MariaDB 🙂

I wish you good luck to try MySQL 8.0 (and also the upcoming MariaDB 10.3)!

Now You Can Create Encrypted Amazon EBS Volumes by Using Your Custom Encryption Keys When You Launch an Amazon EC2 Instance

Post Syndicated from Nishit Nagar original https://aws.amazon.com/blogs/security/create-encrypted-amazon-ebs-volumes-custom-encryption-keys-launch-amazon-ec2-instance-2/

Amazon Elastic Block Store (EBS) offers an encryption solution for your Amazon EBS volumes so you don’t have to build, maintain, and secure your own infrastructure for managing encryption keys for block storage. Amazon EBS encryption uses AWS Key Management Service (AWS KMS) customer master keys (CMKs) when creating encrypted Amazon EBS volumes, providing you all the benefits associated with using AWS KMS. You can specify either an AWS managed CMK or a customer-managed CMK to encrypt your Amazon EBS volume. If you use a customer-managed CMK, you retain granular control over your encryption keys, such as having AWS KMS rotate your CMK every year. To learn more about creating CMKs, see Creating Keys.

In this post, we demonstrate how to create an encrypted Amazon EBS volume using a customer-managed CMK when you launch an EC2 instance from the EC2 console, AWS CLI, and AWS SDK.

Creating an encrypted Amazon EBS volume from the EC2 console

Follow these steps to launch an EC2 instance from the EC2 console with Amazon EBS volumes that are encrypted by customer-managed CMKs:

  1. Sign in to the AWS Management Console and open the EC2 console.
  2. Select Launch instance, and then, in Step 1 of the wizard, select an Amazon Machine Image (AMI).
  3. In Step 2 of the wizard, select an instance type, and then provide additional configuration details in Step 3. For details about configuring your instances, see Launching an Instance.
  4. In Step 4 of the wizard, specify additional EBS volumes that you want to attach to your instances.
  5. To create an encrypted Amazon EBS volume, first add a new volume by selecting Add new volume. Leave the Snapshot column blank.
  6. In the Encrypted column, select your CMK from the drop-down menu. You can also paste the full Amazon Resource Name (ARN) of your custom CMK key ID in this box. To learn more about finding the ARN of a CMK, see Working with Keys.
  7. Select Review and Launch. Your instance will launch with an additional Amazon EBS volume with the key that you selected. To learn more about the launch wizard, see Launching an Instance with Launch Wizard.

Creating Amazon EBS encrypted volumes from the AWS CLI or SDK

You also can use RunInstances to launch an instance with additional encrypted Amazon EBS volumes by setting Encrypted to true and adding kmsKeyID along with the actual key ID in the BlockDeviceMapping object, as shown in the following command:

$> aws ec2 run-instances –image-id ami-b42209de –count 1 –instance-type m4.large –region us-east-1 –block-device-mappings file://mapping.json

In this example, mapping.json describes the properties of the EBS volume that you want to create:


{
"DeviceName": "/dev/sda1",
"Ebs": {
"DeleteOnTermination": true,
"VolumeSize": 100,
"VolumeType": "gp2",
"Encrypted": true,
"kmsKeyID": "arn:aws:kms:us-east-1:012345678910:key/abcd1234-a123-456a-a12b-a123b4cd56ef"
}
}

You can also launch instances with additional encrypted EBS data volumes via an Auto Scaling or Spot Fleet by creating a launch template with the above BlockDeviceMapping. For example:

$> aws ec2 create-launch-template –MyLTName –image-id ami-b42209de –count 1 –instance-type m4.large –region us-east-1 –block-device-mappings file://mapping.json

To learn more about launching an instance with the AWS CLI or SDK, see the AWS CLI Command Reference.

In this blog post, we’ve demonstrated a single-step, streamlined process for creating Amazon EBS volumes that are encrypted under your CMK when you launch your EC2 instance, thereby streamlining your instance launch workflow. To start using this functionality, navigate to the EC2 console.

If you have feedback about this blog post, submit comments in the Comments section below. If you have questions about this blog post, start a new thread on the Amazon EC2 forum or contact AWS Support.

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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.

 

 

 

 

Community profile: Dave Akerman

Post Syndicated from Alex Bate original https://www.raspberrypi.org/blog/community-profile-dave-akerman/

This column is from The MagPi issue 61. You can download a PDF of the full issue for free, or subscribe to receive the print edition through your letterbox or the digital edition on your tablet. All proceeds from the print and digital editions help the Raspberry Pi Foundation achieve our charitable goals.

The pinned tweet on Dave Akerman’s Twitter account shows a table displaying the various components needed for a high-altitude balloon (HAB) flight. Batteries, leads, a camera and Raspberry Pi, plus an unusually themed payload. The caption reads ‘The Queen, The Duke of York, and my TARDIS”, and sums up Dave’s maker career in a heartbeat.

David Akerman on Twitter

The Queen, The Duke of York, and my TARDIS 🙂 #UKHAS #RaspberryPi

Though writing software for industrial automation pays the bills, the majority of Dave’s time is spent in the world of high-altitude ballooning and the ever-growing community that encompasses it. And, while he makes some money sending business-themed balloons to near space for the likes of Aardman Animations, Confused.com, and the BBC, Dave is best known in the Raspberry Pi community for his use of the small computer in every payload, and his work as a tutor alongside the Foundation’s staff at Skycademy events.

Dave Akerman The MagPi Raspberry Pi Community Profile

Dave continues to help others while breaking records and having a good time exploring the atmosphere.

Dave has dedicated many hours and many, many more miles to assist with the Foundation’s Skycademy programme, helping to explore high-altitude ballooning with educators from across the UK. Using a Raspberry Pi and various other pieces of lightweight tech, Dave and Foundation staff member James Robinson explored the incorporation of high-altitude ballooning into education. Through Skycademy, educators were able to learn new skills and take them to the classroom, setting off their own balloons with their students, and recording the results on Raspberry Pis.

Dave Akerman The MagPi Raspberry Pi Community Profile

Dave’s most recent flight broke a new record. On 13 August 2017, his HAB payload was able to send back the highest images taken by any amateur flight.

But education isn’t the only reason for Dave’s involvement in the HAB community. As with anyone passionate about a specific hobby, Dave strives to break records. The most recent record-breaking flight took place on 13 August 2017, when Dave’s Raspberry Pi Zero HAB sent home the highest images taken by any amateur high-altitude balloon launch: at 43014 metres. No other HAB balloon has provided images from such an altitude, and the lightweight nature of the Pi Zero definitely helped, as Dave went on to mention on Twitter a few days later.

Dave Akerman The MagPi Raspberry Pi Community Profile

Dave is recognised as being the first person to incorporate a Raspberry Pi into a HAB payload, and continues to break records with the help of the little green board. More recently, he’s been able to lighten the load by using the Raspberry Pi Zero.

When the first Pi made its way to near space, Dave tore the computer apart in order to meet the weight restriction. The Pi in the Sky board was created to add the extra features needed for the flight. Since then, the HAT has experienced a few changes.

Dave Akerman The MagPi Raspberry Pi Community Profile

The Pi in the Sky board, created specifically for HAB flights.

Dave first fell in love with high-altitude ballooning after coming across the hobby in a video shared on a photographic forum. With a lifelong interest in space thanks to watching the Moon landings as a boy, plus a talent for electronics and photography, it seems a natural progression for him. Throw in his coding skills from learning to program on a Teletype and it’s no wonder he was ready and eager to take to the skies, so to speak, and capture the curvature of the Earth. What was so great about using the Raspberry Pi was the instant gratification he got from receiving images in real time as they were taken during the flight. While other devices could control a camera and store captured images for later retrieval, thanks to the Pi Dave was able to transmit the files back down to Earth and check the progress of his balloon while attempting to break records with a flight.

Dave Akerman The MagPi Raspberry Pi Community Profile Morph

One of the many commercial flights Dave has organised featured the classic children’s TV character Morph, a creation of the Aardman Animations studio known for Wallace and Gromit. Morph took to the sky twice in his mission to reach near space, and finally succeeded in 2016.

High-altitude ballooning isn’t the only part of Dave’s life that incorporates a Raspberry Pi. Having “lost count” of how many Pis he has running tasks, Dave has also created radio receivers for APRS (ham radio data), ADS-B (aircraft tracking), and OGN (gliders), along with a time-lapse camera in his garden, and he has a few more Pi for tinkering purposes.

The post Community profile: Dave Akerman appeared first on Raspberry Pi.

Some notes on memcached DDoS

Post Syndicated from Robert Graham original http://blog.erratasec.com/2018/03/some-notes-on-memcached-ddos.html

I thought I’d write up some notes on the memcached DDoS. Specifically, I describe how many I found scanning the Internet with masscan, and how to use masscan as a killswitch to neuter the worst of the attacks.

Test your servers

I added code to my port scanner for this, then scanned the Internet:
masscan 0.0.0.0/0 -pU:11211 –banners | grep memcached
This example scans the entire Internet (/0). Replaced 0.0.0.0/0 with your address range (or ranges).
This produces output that looks like this:
Banner on port 11211/udp on 172.246.132.226: [memcached] uptime=230130 time=1520485357 version=1.4.13
Banner on port 11211/udp on 89.110.149.218: [memcached] uptime=3935192 time=1520485363 version=1.4.17
Banner on port 11211/udp on 172.246.132.226: [memcached] uptime=230130 time=1520485357 version=1.4.13
Banner on port 11211/udp on 84.200.45.2: [memcached] uptime=399858 time=1520485362 version=1.4.20
Banner on port 11211/udp on 5.1.66.2: [memcached] uptime=29429482 time=1520485363 version=1.4.20
Banner on port 11211/udp on 103.248.253.112: [memcached] uptime=2879363 time=1520485366 version=1.2.6
Banner on port 11211/udp on 193.240.236.171: [memcached] uptime=42083736 time=1520485365 version=1.4.13
The “banners” check filters out those with valid memcached responses, so you don’t get other stuff that isn’t memcached. To filter this output further, use  the ‘cut’ to grab just column 6:
… | cut -d ‘ ‘ -f 6 | cut -d: -f1
You often get multiple responses to just one query, so you’ll want to sort/uniq the list:
… | sort | uniq

My results from an Internet wide scan

I got 15181 results (or roughly 15,000).
People are using Shodan to find a list of memcached servers. They might be getting a lot results back that response to TCP instead of UDP. Only UDP can be used for the attack.

Other researchers scanned the Internet a few days ago and found ~31k. I don’t know if this means people have been removing these from the Internet.

Masscan as exploit script

BTW, you can not only use masscan to find amplifiers, you can also use it to carry out the DDoS. Simply import the list of amplifier IP addresses, then spoof the source address as that of the target. All the responses will go back to the source address.
masscan -iL amplifiers.txt -pU:11211 –spoof-ip –rate 100000
I point this out to show how there’s no magic in exploiting this. Numerous exploit scripts have been released, because it’s so easy.

Why memcached servers are vulnerable

Like many servers, memcached listens to local IP address 127.0.0.1 for local administration. By listening only on the local IP address, remote people cannot talk to the server.
However, this process is often buggy, and you end up listening on either 0.0.0.0 (all interfaces) or on one of the external interfaces. There’s a common Linux network stack issue where this keeps happening, like trying to get VMs connected to the network. I forget the exact details, but the point is that lots of servers that intend to listen only on 127.0.0.1 end up listening on external interfaces instead. It’s not a good security barrier.
Thus, there are lots of memcached servers listening on their control port (11211) on external interfaces.

How the protocol works

The protocol is documented here. It’s pretty straightforward.
The easiest amplification attacks is to send the “stats” command. This is 15 byte UDP packet that causes the server to send back either a large response full of useful statistics about the server.  You often see around 10 kilobytes of response across several packets.
A harder, but more effect attack uses a two step process. You first use the “add” or “set” commands to put chunks of data into the server, then send a “get” command to retrieve it. You can easily put 100-megabytes of data into the server this way, and causes a retrieval with a single “get” command.
That’s why this has been the largest amplification ever, because a single 100-byte packet can in theory cause a 100-megabytes response.
Doing the math, the 1.3 terabit/second DDoS divided across the 15,000 servers I found vulnerable on the Internet leads to an average of 100-megabits/second per server. This is fairly minor, and is indeed something even small servers (like Raspberry Pis) can generate.

Neutering the attack (“kill switch”)

If they are using the more powerful attack against you, you can neuter it: you can send a “flush_all” command back at the servers who are flooding you, causing them to drop all those large chunks of data from the cache.
I’m going to describe how I would do this.
First, get a list of attackers, meaning, the amplifiers that are flooding you. The way to do this is grab a packet sniffer and capture all packets with a source port of 11211. Here is an example using tcpdump.
tcpdump -i -w attackers.pcap src port 11221
Let that run for a while, then hit [ctrl-c] to stop, then extract the list of IP addresses in the capture file. The way I do this is with tshark (comes with Wireshark):
tshark -r attackers.pcap -Tfields -eip.src | sort | uniq > amplifiers.txt
Now, craft a flush_all payload. There are many ways of doing this. For example, if you are using nmap or masscan, you can add the bytes to the nmap-payloads.txt file. Also, masscan can read this directly from a packet capture file. To do this, first craft a packet, such as with the following command line foo:
echo -en “\x00\x00\x00\x00\x00\x01\x00\x00flush_all\r\n” | nc -q1 -u 11211
Capture this packet using tcpdump or something, and save into a file “flush_all.pcap”. If you want to skip this step, I’ve already done this for you, go grab the file from GitHub:
Now that we have our list of attackers (amplifiers.txt) and a payload to blast at them (flush_all.pcap), use masscan to send it:
masscan -iL amplifiers.txt -pU:112211 –pcap-payload flush_all.pcap

Reportedly, “shutdown” may also work to completely shutdown the amplifiers. I’ll leave that as an exercise for the reader, since of course you’ll be adversely affecting the servers.

Some notes

Here are some good reading on this attack:

Amazon Redshift – 2017 Recap

Post Syndicated from Larry Heathcote original https://aws.amazon.com/blogs/big-data/amazon-redshift-2017-recap/

We have been busy adding new features and capabilities to Amazon Redshift, and we wanted to give you a glimpse of what we’ve been doing over the past year. In this article, we recap a few of our enhancements and provide a set of resources that you can use to learn more and get the most out of your Amazon Redshift implementation.

In 2017, we made more than 30 announcements about Amazon Redshift. We listened to you, our customers, and delivered Redshift Spectrum, a feature of Amazon Redshift, that gives you the ability to extend analytics to your data lake—without moving data. We launched new DC2 nodes, doubling performance at the same price. We also announced many new features that provide greater scalability, better performance, more automation, and easier ways to manage your analytics workloads.

To see a full list of our launches, visit our what’s new page—and be sure to subscribe to our RSS feed.

Major launches in 2017

Amazon Redshift Spectrumextend analytics to your data lake, without moving data

We launched Amazon Redshift Spectrum to give you the freedom to store data in Amazon S3, in open file formats, and have it available for analytics without the need to load it into your Amazon Redshift cluster. It enables you to easily join datasets across Redshift clusters and S3 to provide unique insights that you would not be able to obtain by querying independent data silos.

With Redshift Spectrum, you can run SQL queries against data in an Amazon S3 data lake as easily as you analyze data stored in Amazon Redshift. And you can do it without loading data or resizing the Amazon Redshift cluster based on growing data volumes. Redshift Spectrum separates compute and storage to meet workload demands for data size, concurrency, and performance. Redshift Spectrum scales processing across thousands of nodes, so results are fast, even with massive datasets and complex queries. You can query open file formats that you already use—such as Apache Avro, CSV, Grok, ORC, Apache Parquet, RCFile, RegexSerDe, SequenceFile, TextFile, and TSV—directly in Amazon S3, without any data movement.

For complex queries, Redshift Spectrum provided a 67 percent performance gain,” said Rafi Ton, CEO, NUVIAD. “Using the Parquet data format, Redshift Spectrum delivered an 80 percent performance improvement. For us, this was substantial.

To learn more about Redshift Spectrum, watch our AWS Summit session Intro to Amazon Redshift Spectrum: Now Query Exabytes of Data in S3, and read our announcement blog post Amazon Redshift Spectrum – Exabyte-Scale In-Place Queries of S3 Data.

DC2 nodes—twice the performance of DC1 at the same price

We launched second-generation Dense Compute (DC2) nodes to provide low latency and high throughput for demanding data warehousing workloads. DC2 nodes feature powerful Intel E5-2686 v4 (Broadwell) CPUs, fast DDR4 memory, and NVMe-based solid state disks (SSDs). We’ve tuned Amazon Redshift to take advantage of the better CPU, network, and disk on DC2 nodes, providing up to twice the performance of DC1 at the same price. Our DC2.8xlarge instances now provide twice the memory per slice of data and an optimized storage layout with 30 percent better storage utilization.

Redshift allows us to quickly spin up clusters and provide our data scientists with a fast and easy method to access data and generate insights,” said Bradley Todd, technology architect at Liberty Mutual. “We saw a 9x reduction in month-end reporting time with Redshift DC2 nodes as compared to DC1.”

Read our customer testimonials to see the performance gains our customers are experiencing with DC2 nodes. To learn more, read our blog post Amazon Redshift Dense Compute (DC2) Nodes Deliver Twice the Performance as DC1 at the Same Price.

Performance enhancements— 3x-5x faster queries

On average, our customers are seeing 3x to 5x performance gains for most of their critical workloads.

We introduced short query acceleration to speed up execution of queries such as reports, dashboards, and interactive analysis. Short query acceleration uses machine learning to predict the execution time of a query, and to move short running queries to an express short query queue for faster processing.

We launched results caching to deliver sub-second response times for queries that are repeated, such as dashboards, visualizations, and those from BI tools. Results caching has an added benefit of freeing up resources to improve the performance of all other queries.

We also introduced late materialization to reduce the amount of data scanned for queries with predicate filters by batching and factoring in the filtering of predicates before fetching data blocks in the next column. For example, if only 10 percent of the table rows satisfy the predicate filters, Amazon Redshift can potentially save 90 percent of the I/O for the remaining columns to improve query performance.

We launched query monitoring rules and pre-defined rule templates. These features make it easier for you to set metrics-based performance boundaries for workload management (WLM) queries, and specify what action to take when a query goes beyond those boundaries. For example, for a queue that’s dedicated to short-running queries, you might create a rule that aborts queries that run for more than 60 seconds. To track poorly designed queries, you might have another rule that logs queries that contain nested loops.

Customer insights

Amazon Redshift and Redshift Spectrum serve customers across a variety of industries and sizes, from startups to large enterprises. Visit our customer page to see the success that customers are having with our recent enhancements. Learn how companies like Liberty Mutual Insurance saw a 9x reduction in month-end reporting time using DC2 nodes. On this page, you can find case studies, videos, and other content that show how our customers are using Amazon Redshift to drive innovation and business results.

In addition, check out these resources to learn about the success our customers are having building out a data warehouse and data lake integration solution with Amazon Redshift:

Partner solutions

You can enhance your Amazon Redshift data warehouse by working with industry-leading experts. Our AWS Partner Network (APN) Partners have certified their solutions to work with Amazon Redshift. They offer software, tools, integration, and consulting services to help you at every step. Visit our Amazon Redshift Partner page and choose an APN Partner. Or, use AWS Marketplace to find and immediately start using third-party software.

To see what our Partners are saying about Amazon Redshift Spectrum and our DC2 nodes mentioned earlier, read these blog posts:

Resources

Blog posts

Visit the AWS Big Data Blog for a list of all Amazon Redshift articles.

YouTube videos

GitHub

Our community of experts contribute on GitHub to provide tips and hints that can help you get the most out of your deployment. Visit GitHub frequently to get the latest technical guidance, code samples, administrative task automation utilities, the analyze & vacuum schema utility, and more.

Customer support

If you are evaluating or considering a proof of concept with Amazon Redshift, or you need assistance migrating your on-premises or other cloud-based data warehouse to Amazon Redshift, our team of product experts and solutions architects can help you with architecting, sizing, and optimizing your data warehouse. Contact us using this support request form, and let us know how we can assist you.

If you are an Amazon Redshift customer, we offer a no-cost health check program. Our team of database engineers and solutions architects give you recommendations for optimizing Amazon Redshift and Amazon Redshift Spectrum for your specific workloads. To learn more, email us at [email protected].

If you have any questions, email us at [email protected].

 


Additional Reading

If you found this post useful, be sure to check out Amazon Redshift Spectrum – Exabyte-Scale In-Place Queries of S3 Data, Using Amazon Redshift for Fast Analytical Reports and How to Migrate Your Oracle Data Warehouse to Amazon Redshift Using AWS SCT and AWS DMS.


About the Author

Larry Heathcote is a Principle Product Marketing Manager at Amazon Web Services for data warehousing and analytics. Larry is passionate about seeing the results of data-driven insights on business outcomes. He enjoys family time, home projects, grilling out and the taste of classic barbeque.

 

 

 

Running ActiveMQ in a Hybrid Cloud Environment with Amazon MQ

Post Syndicated from Tara Van Unen original https://aws.amazon.com/blogs/compute/running-activemq-in-a-hybrid-cloud-environment-with-amazon-mq/

This post courtesy of Greg Share, AWS Solutions Architect

Many organizations, particularly enterprises, rely on message brokers to connect and coordinate different systems. Message brokers enable distributed applications to communicate with one another, serving as the technological backbone for their IT environment, and ultimately their business services. Applications depend on messaging to work.

In many cases, those organizations have started to build new or “lift and shift” applications to AWS. In some cases, there are applications, such as mainframe systems, too costly to migrate. In these scenarios, those on-premises applications still need to interact with cloud-based components.

Amazon MQ is a managed message broker service for ActiveMQ that enables organizations to send messages between applications in the cloud and on-premises to enable hybrid environments and application modernization. For example, you can invoke AWS Lambda from queues and topics managed by Amazon MQ brokers to integrate legacy systems with serverless architectures. ActiveMQ is an open-source message broker written in Java that is packaged with clients in multiple languages, Java Message Server (JMS) client being one example.

This post shows you can use Amazon MQ to integrate on-premises and cloud environments using the network of brokers feature of ActiveMQ. It provides configuration parameters for a one-way duplex connection for the flow of messages from an on-premises ActiveMQ message broker to Amazon MQ.

ActiveMQ and the network of brokers

First, look at queues within ActiveMQ and then at the network of brokers as a mechanism to distribute messages.

The network of brokers behaves differently from models such as physical networks. The key consideration is that the production (sending) of a message is disconnected from the consumption of that message. Think of the delivery of a parcel: The parcel is sent by the supplier (producer) to the end customer (consumer). The path it took to get there is of little concern to the customer, as long as it receives the package.

The same logic can be applied to the network of brokers. Here’s how you build the flow from a simple message to a queue and build toward a network of brokers. Before you look at setting up a hybrid connection, I discuss how a broker processes messages in a simple scenario.

When a message is sent from a producer to a queue on a broker, the following steps occur:

  1. A message is sent to a queue from the producer.
  2. The broker persists this in its store or journal.
  3. At this point, an acknowledgement (ACK) is sent to the producer from the broker.

When a consumer looks to consume the message from that same queue, the following steps occur:

  1. The message listener (consumer) calls the broker, which creates a subscription to the queue.
  2. Messages are fetched from the message store and sent to the consumer.
  3. The consumer acknowledges that the message has been received before processing it.
  4. Upon receiving the ACK, the broker sets the message as having been consumed. By default, this deletes it from the queue.
    • You can set the consumer to ACK after processing by setting up transaction management or handle it manually using Session.CLIENT_ACKNOWLEDGE.

Static propagation

I now introduce the concept of static propagation with the network of brokers as the mechanism for message transfer from on-premises brokers to Amazon MQ.  Static propagation refers to message propagation that occurs in the absence of subscription information. In this case, the objective is to transfer messages arriving at your selected on-premises broker to the Amazon MQ broker for consumption within the cloud environment.

After you configure static propagation with a network of brokers, the following occurs:

  1. The on-premises broker receives a message from a producer for a specific queue.
  2. The on-premises broker sends (statically propagates) the message to the Amazon MQ broker.
  3. The Amazon MQ broker sends an acknowledgement to the on-premises broker, which marks the message as having been consumed.
  4. Amazon MQ holds the message in its queue ready for consumption.
  5. A consumer connects to Amazon MQ broker, subscribes to the queue in which the message resides, and receives the message.
  6. Amazon MQ broker marks the message as having been consumed.

Getting started

The first step is creating an Amazon MQ broker.

  1. Sign in to the Amazon MQ console and launch a new Amazon MQ broker.
  2. Name your broker and choose Next step.
  3. For Broker instance type, choose your instance size:
    mq.t2.micro
    mq.m4.large
  4. For Deployment mode, enter one of the following:
    Single-instance broker for development and test implementations (recommended)
    Active/standby broker for high availability in production environments
  5. Scroll down and enter your user name and password.
  6. Expand Advanced Settings.
  7. For VPC, Subnet, and Security Group, pick the values for the resources in which your broker will reside.
  8. For Public Accessibility, choose Yes, as connectivity is internet-based. Another option would be to use private connectivity between your on-premises network and the VPC, an example being an AWS Direct Connect or VPN connection. In that case, you could set Public Accessibility to No.
  9. For Maintenance, leave the default value, No preference.
  10. Choose Create Broker. Wait several minutes for the broker to be created.

After creation is complete, you see your broker listed.

For connectivity to work, you must configure the security group where Amazon MQ resides. For this post, I focus on the OpenWire protocol.

For Openwire connectivity, allow port 61617 access for Amazon MQ from your on-premises ActiveMQ broker source IP address. For alternate protocols, see the Amazon MQ broker configuration information for the ports required:

OpenWire – ssl://xxxxxxx.xxx.com:61617
AMQP – amqp+ssl:// xxxxxxx.xxx.com:5671
STOMP – stomp+ssl:// xxxxxxx.xxx.com:61614
MQTT – mqtt+ssl:// xxxxxxx.xxx.com:8883
WSS – wss:// xxxxxxx.xxx.com:61619

Configuring the network of brokers

Configuring the network of brokers with static propagation occurs on the on-premises broker by applying changes to the following file:
<activemq install directory>/conf activemq.xml

Network connector

This is the first configuration item required to enable a network of brokers. It is only required on the on-premises broker, which initiates and creates the connection with Amazon MQ. This connection, after it’s established, enables the flow of messages in either direction between the on-premises broker and Amazon MQ. The focus of this post is the uni-directional flow of messages from the on-premises broker to Amazon MQ.

The default activemq.xml file does not include the network connector configuration. Add this with the networkConnector element. In this scenario, edit the on-premises broker activemq.xml file to include the following information between <systemUsage> and <transportConnectors>:

<networkConnectors>
             <networkConnector 
                name="Q:source broker name->target broker name"
                duplex="false" 
                uri="static:(ssl:// aws mq endpoint:61617)" 
                userName="username"
                password="password" 
                networkTTL="2" 
                dynamicOnly="false">
                <staticallyIncludedDestinations>
                    <queue physicalName="queuename"/>
                </staticallyIncludedDestinations> 
                <excludedDestinations>
                      <queue physicalName=">" />
                </excludedDestinations>
             </networkConnector> 
     <networkConnectors>

The highlighted components are the most important elements when configuring your on-premises broker.

  • name – Name of the network bridge. In this case, it specifies two things:
    • That this connection relates to an ActiveMQ queue (Q) as opposed to a topic (T), for reference purposes.
    • The source broker and target broker.
  • duplex –Setting this to false ensures that messages traverse uni-directionally from the on-premises broker to Amazon MQ.
  • uri –Specifies the remote endpoint to which to connect for message transfer. In this case, it is an Openwire endpoint on your Amazon MQ broker. This information could be obtained from the Amazon MQ console or via the API.
  • username and password – The same username and password configured when creating the Amazon MQ broker, and used to access the Amazon MQ ActiveMQ console.
  • networkTTL – Number of brokers in the network through which messages and subscriptions can pass. Leave this setting at the current value, if it is already included in your broker connection.
  • staticallyIncludedDestinations > queue physicalName – The destination ActiveMQ queue for which messages are destined. This is the queue that is propagated from the on-premises broker to the Amazon MQ broker for message consumption.

After the network connector is configured, you must restart the ActiveMQ service on the on-premises broker for the changes to be applied.

Verify the configuration

There are a number of places within the ActiveMQ console of your on-premises and Amazon MQ brokers to browse to verify that the configuration is correct and the connection has been established.

On-premises broker

Launch the ActiveMQ console of your on-premises broker and navigate to Network. You should see an active network bridge similar to the following:

This identifies that the connection between your on-premises broker and your Amazon MQ broker is up and running.

Now navigate to Connections and scroll to the bottom of the page. Under the Network Connectors subsection, you should see a connector labeled with the name: value that you provided within the ActiveMQ.xml configuration file. You should see an entry similar to:

Amazon MQ broker

Launch the ActiveMQ console of your Amazon MQ broker and navigate to Connections. Scroll to the Connections openwire subsection and you should see a connection specified that references the name: value that you provided within the ActiveMQ.xml configuration file. You should see an entry similar to:

If you configured the uri: for AMQP, STOMP, MQTT, or WSS as opposed to Openwire, you would see this connection under the corresponding section of the Connections page.

Testing your message flow

The setup described outlines a way for messages produced on premises to be propagated to the cloud for consumption in the cloud. This section provides steps on verifying the message flow.

Verify that the queue has been created

After you specify this queue name as staticallyIncludedDestinations > queue physicalName: and your ActiveMQ service starts, you see the following on your on-premises ActiveMQ console Queues page.

As you can see, no messages have been sent but you have one consumer listed. If you then choose Active Consumers under the Views column, you see Active Consumers for TestingQ.

This is telling you that your Amazon MQ broker is a consumer of your on-premises broker for the testing queue.

Produce and send a message to the on-premises broker

Now, produce a message on an on-premises producer and send it to your on-premises broker to a queue named TestingQ. If you navigate back to the queues page of your on-premises ActiveMQ console, you see that the messages enqueued and messages dequeued column count for your TestingQ queue have changed:

What this means is that the message originating from the on-premises producer has traversed the on-premises broker and propagated immediately to the Amazon MQ broker. At this point, the message is no longer available for consumption from the on-premises broker.

If you access the ActiveMQ console of your Amazon MQ broker and navigate to the Queues page, you see the following for the TestingQ queue:

This means that the message originally sent to your on-premises broker has traversed the network of brokers unidirectional network bridge, and is ready to be consumed from your Amazon MQ broker. The indicator is the Number of Pending Messages column.

Consume the message from an Amazon MQ broker

Connect to the Amazon MQ TestingQ queue from a consumer within the AWS Cloud environment for message consumption. Log on to the ActiveMQ console of your Amazon MQ broker and navigate to the Queue page:

As you can see, the Number of Pending Messages column figure has changed to 0 as that message has been consumed.

This diagram outlines the message lifecycle from the on-premises producer to the on-premises broker, traversing the hybrid connection between the on-premises broker and Amazon MQ, and finally consumption within the AWS Cloud.

Conclusion

This post focused on an ActiveMQ-specific scenario for transferring messages within an ActiveMQ queue from an on-premises broker to Amazon MQ.

For other on-premises brokers, such as IBM MQ, another approach would be to run ActiveMQ on-premises broker and use JMS bridging to IBM MQ, while using the approach in this post to forward to Amazon MQ. Yet another approach would be to use Apache Camel for more sophisticated routing.

I hope that you have found this example of hybrid messaging between an on-premises environment in the AWS Cloud to be useful. Many customers are already using on-premises ActiveMQ brokers, and this is a great use case to enable hybrid cloud scenarios.

To learn more, see the Amazon MQ website and Developer Guide. You can try Amazon MQ for free with the AWS Free Tier, which includes up to 750 hours of a single-instance mq.t2.micro broker and up to 1 GB of storage per month for one year.

 

Community Profile: Estefannie Explains It All

Post Syndicated from Alex Bate original https://www.raspberrypi.org/blog/community-profile-estefannie/

This column is from The MagPi issue 59. You can download a PDF of the full issue for free, or subscribe to receive the print edition through your letterbox or the digital edition on your tablet. All proceeds from the print and digital editions help the Raspberry Pi Foundation achieve our charitable goals.

“Hey, world!” Estefannie exclaims, a wide grin across her face as the camera begins to roll for another YouTube tutorial video. With a growing number of followers and wonderful support from her fans, Estefannie is building a solid reputation as an online maker, creating unique, fun content accessible to all.

A woman sitting at a desk with a laptop and papers — Estefannie Explains it All Raspberry Pi

It’s as if she was born into performing and making for an audience, but this fun, enjoyable journey to social media stardom came not from a desire to be in front of the camera, but rather as a unique approach to her own learning. While studying, Estefannie decided the best way to confirm her knowledge of a subject was to create an educational video explaining it. If she could teach a topic successfully, she knew she’d retained the information. And so her YouTube channel, Estefannie Explains It All, came into being.

Note taking — Estefannie Explains it All

Her first videos featured pages of notes with voice-over explanations of data structure and algorithm analysis. Then she moved in front of the camera, and expanded her skills in the process.

But YouTube isn’t her only outlet. With nearly 50000 followers, Estefannie’s Instagram game is strong, adding to an increasing number of female coders taking to the platform. Across her Instagram grid, you’ll find insights into her daily routine, from programming on location for work to behind-the-scenes troubleshooting as she begins to create another tutorial video. It’s hard work, with content creation for both Instagram and YouTube forever on her mind as she continues to work and progress successfully as a software engineer.

A woman showing off a game on a tablet — Estefannie Explains it All Raspberry Pi

As a thank you to her Instagram fans for helping her reach 10000 followers, Estefannie created a free game for Android and iOS called Gravitris — imagine Tetris with balance issues!

Estefannie was born and raised in Mexico, with ambitions to become a graphic designer and animator. However, a documentary on coding at Pixar, and the beauty of Merida’s hair in Brave, opened her mind to the opportunities of software engineering in animation. She altered her career path, moved to the United States, and switched to a Computer Science course.

A woman wearing safety goggles hugging a keyboard Estefannie Explains it All Raspberry Pi

With a constant desire to make and to learn, Estefannie combines her software engineering profession with her hobby to create fun, exciting content for YouTube.

While studying, Estefannie started a Computer Science Girls Club at the University of Houston, Texas, and she found herself eager to put more time and effort into the movement to increase the percentage of women in the industry. The club was a success, and still is to this day. While Estefannie has handed over the reins, she’s still very involved in the cause.

Through her YouTube videos, Estefannie continues the theme of inclusion, with every project offering a warm sense of approachability for all, regardless of age, gender, or skill. From exploring Scratch and Makey Makey with her young niece and nephew to creating her own Disney ‘Made with Magic’ backpack for a trip to Disney World, Florida, Estefannie’s videos are essentially a documentary of her own learning process, produced so viewers can learn with her — and learn from her mistakes — to create their own tech wonders.

Using the Raspberry Pi, she’s been able to broaden her skills and, in turn, her projects, creating a home-automated gingerbread house at Christmas, building a GPS-controlled GoPro for her trip to London, and making everyone’s life better with an Internet Button–controlled French press.

Estefannie Explains it All Raspberry Pi Home Automated Gingerbread House

Estefannie’s automated gingerbread house project was a labour of love, with electronics, wires, and candy strewn across both her living room and kitchen for weeks before completion. While she already was a skilled programmer, the world of physical digital making was still fairly new for Estefannie. Having ditched her hot glue gun in favour of a soldering iron in a previous video, she continued to experiment and try out new, interesting techniques that are now second nature to many members of the maker community. With the gingerbread house, Estefannie was able to research and apply techniques such as light controls, servos, and app making, although the latter was already firmly within her skill set. The result? A fun video of ups and downs that resulted in a wonderful, festive treat. She even gave her holiday home its own solar panel!

A DAY AT RASPBERRY PI TOWERS!! LINK IN BIO ⚡🎥 @raspberrypifoundation

1,910 Likes, 43 Comments – Estefannie Explains It All (@estefanniegg) on Instagram: “A DAY AT RASPBERRY PI TOWERS!! LINK IN BIO ⚡🎥 @raspberrypifoundation”

And that’s just the beginning of her adventures with Pi…but we won’t spoil her future plans by telling you what’s coming next. Sorry! However, since this article was written last year, Estefannie has released a few more Pi-based project videos, plus some awesome interviews and live-streams with other members of the maker community such as Simone Giertz. She even made us an awesome video for our Raspberry Pi YouTube channel! So be sure to check out her latest releases.

Best day yet!! I got to hangout, play Jenga with a huge arm robot, and have afternoon tea with @simonegiertz and robots!! 🤖👯 #shittyrobotnation

2,264 Likes, 56 Comments – Estefannie Explains It All (@estefanniegg) on Instagram: “Best day yet!! I got to hangout, play Jenga with a huge arm robot, and have afternoon tea with…”

While many wonderful maker videos show off a project without much explanation, or expect a certain level of skill from viewers hoping to recreate the project, Estefannie’s videos exist almost within their own category. We can’t wait to see where Estefannie Explains It All goes next!

The post Community Profile: Estefannie Explains It All appeared first on Raspberry Pi.

Community Profile: Dr. Lucy Rogers

Post Syndicated from Alex Bate original https://www.raspberrypi.org/blog/community-profile-lucy-rogers/

This column is from The MagPi issue 58. You can download a PDF of the full issue for free, or subscribe to receive the print edition through your letterbox or the digital edition on your tablet. All proceeds from the print and digital editions help the Raspberry Pi Foundation achieve our charitable goals.

Dr Lucy Rogers calls herself a Transformer. “I transform simple electronics into cool gadgets, I transform science into plain English, I transform problems into opportunities. I am also a catalyst. I am interested in everything around me, and can often see ways of putting two ideas from very different fields together into one package. If I cannot do this myself, I connect the people who can.”

Dr Lucy Rogers Raspberry Pi The MagPi Community Profile

Among many other projects, Dr Lucy Rogers currently focuses much of her attention on reducing the damage from space debris

It’s a pretty wide range of interests and skills for sure. But it only takes a brief look at Lucy’s résumé to realise that she means it. When she says she’s interested in everything around her, this interest reaches from electronics to engineering, wearable tech, space, robotics, and robotic dinosaurs. And she can be seen talking about all of these things across various companies’ social media, such as IBM, websites including the Women’s Engineering Society, and books, including her own.

Dr Lucy Rogers Raspberry Pi The MagPi Community Profile

With her bright LED boots, Lucy was one of the wonderful Pi community members invited to join us and HRH The Duke of York at St James’s Palace just over a year ago

When not attending conferences as guest speaker, tinkering with electronics, or creating engaging IoT tutorials, she can be found retrofitting Raspberry Pis into the aforementioned robotic dinosaurs at Blackgang Chine Land of Imagination, writing, and judging battling bots for the BBC’s Robot Wars.

Dr Lucy Rogers Raspberry Pi The MagPi Community Profile

First broadcast in the UK between 1998 and 2004, Robot Wars was revived in 2016 with a new look and new judges, including Dr Lucy Rogers. Competitors battle their home-brew robots, and Lucy, together with the other two judges, awards victories among the carnage of robotic remains

Lucy graduated from Lancaster University with a degree in Mechanical Engineering. After that, she spent seven years at Rolls-Royce Industrial Power Group as a graduate trainee before becoming a chartered engineer and earning her PhD in bubbles.

Bubbles?

“Foam formation in low‑expansion fire-fighting equipment. I investigated the equipment to determine how the bubbles were formed,” she explains. Obviously. Bubbles!

Dr Lucy Rogers Raspberry Pi The MagPi Community Profile

Lucy graduated from the Singularity University Graduate Studies Program in 2011, focusing on how robotics, nanotech, medicine, and various technologies can tackle the challenges facing the world

She then went on to become a fellow of the Royal Astronomical Society (RAS) in 2005 and, later, a fellow of both the Institution of Mechanical Engineers (IMechE) and British Interplanetary Society. As a member of the Association of British Science Writers, Lucy wrote It’s ONLY Rocket Science: an Introduction in Plain English.

Dr Lucy Rogers Raspberry Pi The MagPi Community Profile

In It’s Only Rocket Science: An Introduction in Plain English Lucy explains that ‘hard to understand’ isn’t the same as ‘impossible to understand’, and takes her readers through the journey of building a rocket, leaving Earth, and travelling the cosmos

As a standout member of the industry, and all-round fun person to be around, Lucy has quickly established herself as a valued member of the Pi community.

In 2014, with the help of Neil Ford and Andy Stanford-Clark, Lucy worked with the UK’s oldest amusement park, Blackgang Chine Land of Imagination, on the Isle of Wight, with the aim of updating its animatronic dinosaurs. The original Blackgang Chine dinosaurs had a limited range of behaviour: able to roar, move their heads, and stomp a foot in a somewhat repetitive action.

When she contacted Raspberry Pi back in the November of that same year, the team were working on more creative, varied behaviours, giving each dinosaur a new Raspberry Pi-sized brain. This later evolved into a very successful dino-hacking Raspberry Jam.

Dr Lucy Rogers Raspberry Pi The MagPi Community Profile

Lucy, Neil Ford, and Andy Stanford-Clark used several Raspberry Pis and Node-RED to visualise flows of events when updating the robotic dinosaurs at Blackgang Chine. They went on to create the successful WightPi Raspberry Jam event, where visitors could join in with the unique hacking opportunity.

Given her love for tinkering with tech, and a love for stand-up comedy that can be uncovered via a quick YouTube search, it’s no wonder that Lucy was asked to help judge the first round of the ‘Make us laugh’ Pioneers challenge for Raspberry Pi. Alongside comedian Bec Hill, Code Club UK director Maria Quevedo, and the face of the first challenge, Owen Daughtery, Lucy lent her expertise to help name winners in the various categories of the teens event, and offered her support to future Pioneers.

The post Community Profile: Dr. Lucy Rogers appeared first on Raspberry Pi.

Top 8 Best Practices for High-Performance ETL Processing Using Amazon Redshift

Post Syndicated from Thiyagarajan Arumugam original https://aws.amazon.com/blogs/big-data/top-8-best-practices-for-high-performance-etl-processing-using-amazon-redshift/

An ETL (Extract, Transform, Load) process enables you to load data from source systems into your data warehouse. This is typically executed as a batch or near-real-time ingest process to keep the data warehouse current and provide up-to-date analytical data to end users.

Amazon Redshift is a fast, petabyte-scale data warehouse that enables you easily to make data-driven decisions. With Amazon Redshift, you can get insights into your big data in a cost-effective fashion using standard SQL. You can set up any type of data model, from star and snowflake schemas, to simple de-normalized tables for running any analytical queries.

To operate a robust ETL platform and deliver data to Amazon Redshift in a timely manner, design your ETL processes to take account of Amazon Redshift’s architecture. When migrating from a legacy data warehouse to Amazon Redshift, it is tempting to adopt a lift-and-shift approach, but this can result in performance and scale issues long term. This post guides you through the following best practices for ensuring optimal, consistent runtimes for your ETL processes:

  • COPY data from multiple, evenly sized files.
  • Use workload management to improve ETL runtimes.
  • Perform table maintenance regularly.
  • Perform multiple steps in a single transaction.
  • Loading data in bulk.
  • Use UNLOAD to extract large result sets.
  • Use Amazon Redshift Spectrum for ad hoc ETL processing.
  • Monitor daily ETL health using diagnostic queries.

1. COPY data from multiple, evenly sized files

Amazon Redshift is an MPP (massively parallel processing) database, where all the compute nodes divide and parallelize the work of ingesting data. Each node is further subdivided into slices, with each slice having one or more dedicated cores, equally dividing the processing capacity. The number of slices per node depends on the node type of the cluster. For example, each DS2.XLARGE compute node has two slices, whereas each DS2.8XLARGE compute node has 16 slices.

When you load data into Amazon Redshift, you should aim to have each slice do an equal amount of work. When you load the data from a single large file or from files split into uneven sizes, some slices do more work than others. As a result, the process runs only as fast as the slowest, or most heavily loaded, slice. In the example shown below, a single large file is loaded into a two-node cluster, resulting in only one of the nodes, “Compute-0”, performing all the data ingestion:

When splitting your data files, ensure that they are of approximately equal size – between 1 MB and 1 GB after compression. The number of files should be a multiple of the number of slices in your cluster. Also, I strongly recommend that you individually compress the load files using gzip, lzop, or bzip2 to efficiently load large datasets.

When loading multiple files into a single table, use a single COPY command for the table, rather than multiple COPY commands. Amazon Redshift automatically parallelizes the data ingestion. Using a single COPY command to bulk load data into a table ensures optimal use of cluster resources, and quickest possible throughput.

2. Use workload management to improve ETL runtimes

Use Amazon Redshift’s workload management (WLM) to define multiple queues dedicated to different workloads (for example, ETL versus reporting) and to manage the runtimes of queries. As you migrate more workloads into Amazon Redshift, your ETL runtimes can become inconsistent if WLM is not appropriately set up.

I recommend limiting the overall concurrency of WLM across all queues to around 15 or less. This WLM guide helps you organize and monitor the different queues for your Amazon Redshift cluster.

When managing different workloads on your Amazon Redshift cluster, consider the following for the queue setup:

  • Create a queue dedicated to your ETL processes. Configure this queue with a small number of slots (5 or fewer). Amazon Redshift is designed for analytics queries, rather than transaction processing. The cost of COMMIT is relatively high, and excessive use of COMMIT can result in queries waiting for access to the commit queue. Because ETL is a commit-intensive process, having a separate queue with a small number of slots helps mitigate this issue.
  • Claim extra memory available in a queue. When executing an ETL query, you can take advantage of the wlm_query_slot_count to claim the extra memory available in a particular queue. For example, a typical ETL process might involve COPYing raw data into a staging table so that downstream ETL jobs can run transformations that calculate daily, weekly, and monthly aggregates. To speed up the COPY process (so that the downstream tasks can start in parallel sooner), the wlm_query_slot_count can be increased for this step.
  • Create a separate queue for reporting queries. Configure query monitoring rules on this queue to further manage long-running and expensive queries.
  • Take advantage of the dynamic memory parameters. They swap the memory from your ETL to your reporting queue after the ETL job has completed.

3. Perform table maintenance regularly

Amazon Redshift is a columnar database, which enables fast transformations for aggregating data. Performing regular table maintenance ensures that transformation ETLs are predictable and performant. To get the best performance from your Amazon Redshift database, you must ensure that database tables regularly are VACUUMed and ANALYZEd. The Analyze & Vacuum schema utility helps you automate the table maintenance task and have VACUUM & ANALYZE executed in a regular fashion.

  • Use VACUUM to sort tables and remove deleted blocks

During a typical ETL refresh process, tables receive new incoming records using COPY, and unneeded data (cold data) is removed using DELETE. New rows are added to the unsorted region in a table. Deleted rows are simply marked for deletion.

DELETE does not automatically reclaim the space occupied by the deleted rows. Adding and removing large numbers of rows can therefore cause the unsorted region and the number of deleted blocks to grow. This can degrade the performance of queries executed against these tables.

After an ETL process completes, perform VACUUM to ensure that user queries execute in a consistent manner. The complete list of tables that need VACUUMing can be found using the Amazon Redshift Util’s table_info script.

Use the following approaches to ensure that VACCUM is completed in a timely manner:

  • Use wlm_query_slot_count to claim all the memory allocated in the ETL WLM queue during the VACUUM process.
  • DROP or TRUNCATE intermediate or staging tables, thereby eliminating the need to VACUUM them.
  • If your table has a compound sort key with only one sort column, try to load your data in sort key order. This helps reduce or eliminate the need to VACUUM the table.
  • Consider using time series This helps reduce the amount of data you need to VACUUM.
  • Use ANALYZE to update database statistics

Amazon Redshift uses a cost-based query planner and optimizer using statistics about tables to make good decisions about the query plan for the SQL statements. Regular statistics collection after the ETL completion ensures that user queries run fast, and that daily ETL processes are performant. The Amazon Redshift utility table_info script provides insights into the freshness of the statistics. Keeping the statistics off (pct_stats_off) less than 20% ensures effective query plans for the SQL queries.

4. Perform multiple steps in a single transaction

ETL transformation logic often spans multiple steps. Because commits in Amazon Redshift are expensive, if each ETL step performs a commit, multiple concurrent ETL processes can take a long time to execute.

To minimize the number of commits in a process, the steps in an ETL script should be surrounded by a BEGIN…END statement so that a single commit is performed only after all the transformation logic has been executed. For example, here is an example multi-step ETL script that performs one commit at the end:

Begin
CREATE temporary staging_table;
INSERT INTO staging_table SELECT .. FROM source (transformation logic);
DELETE FROM daily_table WHERE dataset_date =?;
INSERT INTO daily_table SELECT .. FROM staging_table (daily aggregate);
DELETE FROM weekly_table WHERE weekending_date=?;
INSERT INTO weekly_table SELECT .. FROM staging_table(weekly aggregate);
Commit

5. Loading data in bulk

Amazon Redshift is designed to store and query petabyte-scale datasets. Using Amazon S3 you can stage and accumulate data from multiple source systems before executing a bulk COPY operation. The following methods allow efficient and fast transfer of these bulk datasets into Amazon Redshift:

  • Use a manifest file to ingest large datasets that span multiple files. The manifest file is a JSON file that lists all the files to be loaded into Amazon Redshift. Using a manifest file ensures that Amazon Redshift has a consistent view of the data to be loaded from S3, while also ensuring that duplicate files do not result in the same data being loaded more than one time.
  • Use temporary staging tables to hold the data for transformation. These tables are automatically dropped after the ETL session is complete. Temporary tables can be created using the CREATE TEMPORARY TABLE syntax, or by issuing a SELECT … INTO #TEMP_TABLE query. Explicitly specifying the CREATE TEMPORARY TABLE statement allows you to control the DISTRIBUTION KEY, SORT KEY, and compression settings to further improve performance.
  • User ALTER table APPEND to swap data from the staging tables to the target table. Data in the source table is moved to matching columns in the target table. Column order doesn’t matter. After data is successfully appended to the target table, the source table is empty. ALTER TABLE APPEND is much faster than a similar CREATE TABLE AS or INSERT INTO operation because it doesn’t involve copying or moving data.

6. Use UNLOAD to extract large result sets

Fetching a large number of rows using SELECT is expensive and takes a long time. When a large amount of data is fetched from the Amazon Redshift cluster, the leader node has to hold the data temporarily until the fetches are complete. Further, data is streamed out sequentially, which results in longer elapsed time. As a result, the leader node can become hot, which not only affects the SELECT that is being executed, but also throttles resources for creating execution plans and managing the overall cluster resources. Here is an example of a large SELECT statement. Notice that the leader node is doing most of the work to stream out the rows:

Use UNLOAD to extract large results sets directly to S3. After it’s in S3, the data can be shared with multiple downstream systems. By default, UNLOAD writes data in parallel to multiple files according to the number of slices in the cluster. All the compute nodes participate to quickly offload the data into S3.

If you are extracting data for use with Amazon Redshift Spectrum, you should make use of the MAXFILESIZE parameter to and keep files are 150 MB. Similar to item 1 above, having many evenly sized files ensures that Redshift Spectrum can do the maximum amount of work in parallel.

7. Use Redshift Spectrum for ad hoc ETL processing

Events such as data backfill, promotional activity, and special calendar days can trigger additional data volumes that affect the data refresh times in your Amazon Redshift cluster. To help address these spikes in data volumes and throughput, I recommend staging data in S3. After data is organized in S3, Redshift Spectrum enables you to query it directly using standard SQL. In this way, you gain the benefits of additional capacity without having to resize your cluster.

For tips on getting started with and optimizing the use of Redshift Spectrum, see the previous post, 10 Best Practices for Amazon Redshift Spectrum.

8. Monitor daily ETL health using diagnostic queries

Monitoring the health of your ETL processes on a regular basis helps identify the early onset of performance issues before they have a significant impact on your cluster. The following monitoring scripts can be used to provide insights into the health of your ETL processes:

Script Use when… Solution
commit_stats.sql – Commit queue statistics from past days, showing largest queue length and queue time first DML statements such as INSERT/UPDATE/COPY/DELETE operations take several times longer to execute when multiple of these operations are in progress Set up separate WLM queues for the ETL process and limit the concurrency to < 5.
copy_performance.sql –  Copy command statistics for the past days Daily COPY operations take longer to execute • Follow the best practices for the COPY command.
• Analyze data growth with the incoming datasets and consider cluster resize to meet the expected SLA.
table_info.sql – Table skew and unsorted statistics along with storage and key information Transformation steps take longer to execute • Set up regular VACCUM jobs to address unsorted rows and claim the deleted blocks so that transformation SQL execute optimally.
• Consider a table redesign to avoid data skewness.
v_check_transaction_locks.sql – Monitor transaction locks INSERT/UPDATE/COPY/DELETE operations on particular tables do not respond back in timely manner, compared to when run after the ETL Multiple DML statements are operating on the same target table at the same moment from different transactions. Set up ETL job dependency so that they execute serially for the same target table.
v_get_schema_priv_by_user.sql – Get the schema that the user has access to Reporting users can view intermediate tables Set up separate database groups for reporting and ETL users, and grants access to objects using GRANT.
v_generate_tbl_ddl.sql – Get the table DDL You need to create an empty table with same structure as target table for data backfill Generate DDL using this script for data backfill.
v_space_used_per_tbl.sql – monitor space used by individual tables Amazon Redshift data warehouse space growth is trending upwards more than normal

Analyze the individual tables that are growing at higher rate than normal. Consider data archival using UNLOAD to S3 and Redshift Spectrum for later analysis.

Use unscanned_table_summary.sql to find unused table and archive or drop them.

top_queries.sql – Return the top 50 time consuming statements aggregated by its text ETL transformations are taking longer to execute Analyze the top transformation SQL and use EXPLAIN to find opportunities for tuning the query plan.

There are several other useful scripts available in the amazon-redshift-utils repository. The AWS Lambda Utility Runner runs a subset of these scripts on a scheduled basis, allowing you to automate much of monitoring of your ETL processes.

Example ETL process

The following ETL process reinforces some of the best practices discussed in this post. Consider the following four-step daily ETL workflow where data from an RDBMS source system is staged in S3 and then loaded into Amazon Redshift. Amazon Redshift is used to calculate daily, weekly, and monthly aggregations, which are then unloaded to S3, where they can be further processed and made available for end-user reporting using a number of different tools, including Redshift Spectrum and Amazon Athena.

Step 1:  Extract from the RDBMS source to a S3 bucket

In this ETL process, the data extract job fetches change data every 1 hour and it is staged into multiple hourly files. For example, the staged S3 folder looks like the following:

 [[email protected] ~]$ aws s3 ls s3://<<S3 Bucket>>/batch/2017/07/02/
2017-07-02 01:59:58   81900220 20170702T01.export.gz
2017-07-02 02:59:56   84926844 20170702T02.export.gz
2017-07-02 03:59:54   78990356 20170702T03.export.gz
…
2017-07-02 22:00:03   75966745 20170702T21.export.gz
2017-07-02 23:00:02   89199874 20170702T22.export.gz
2017-07-02 00:59:59   71161715 20170702T23.export.gz

Organizing the data into multiple, evenly sized files enables the COPY command to ingest this data using all available resources in the Amazon Redshift cluster. Further, the files are compressed (gzipped) to further reduce COPY times.

Step 2: Stage data to the Amazon Redshift table for cleansing

Ingesting the data can be accomplished using a JSON-based manifest file. Using the manifest file ensures that S3 eventual consistency issues can be eliminated and also provides an opportunity to dedupe any files if needed. A sample manifest20170702.json file looks like the following:

{
  "entries": [
    {"url":" s3://<<S3 Bucket>>/batch/2017/07/02/20170702T01.export.gz", "mandatory":true},
    {"url":" s3://<<S3 Bucket>>/batch/2017/07/02/20170702T02.export.gz", "mandatory":true},
    …
    {"url":" s3://<<S3 Bucket>>/batch/2017/07/02/20170702T23.export.gz", "mandatory":true}
  ]
}

The data can be ingested using the following command:

SET wlm_query_slot_count TO <<max available concurrency in the ETL queue>>;
COPY stage_tbl FROM 's3:// <<S3 Bucket>>/batch/manifest20170702.json' iam_role 'arn:aws:iam::0123456789012:role/MyRedshiftRole' manifest;

Because the downstream ETL processes depend on this COPY command to complete, the wlm_query_slot_count is used to claim all the memory available to the queue. This helps the COPY command complete as quickly as possible.

Step 3: Transform data to create daily, weekly, and monthly datasets and load into target tables

Data is staged in the “stage_tbl” from where it can be transformed into the daily, weekly, and monthly aggregates and loaded into target tables. The following job illustrates a typical weekly process:

Begin
INSERT into ETL_LOG (..) values (..);
DELETE from weekly_tbl where dataset_week = <<current week>>;
INSERT into weekly_tbl (..)
  SELECT date_trunc('week', dataset_day) AS week_begin_dataset_date, SUM(C1) AS C1, SUM(C2) AS C2
	FROM   stage_tbl
GROUP BY date_trunc('week', dataset_day);
INSERT into AUDIT_LOG values (..);
COMMIT;
End;

As shown above, multiple steps are combined into one transaction to perform a single commit, reducing contention on the commit queue.

Step 4: Unload the daily dataset to populate the S3 data lake bucket

The transformed results are now unloaded into another S3 bucket, where they can be further processed and made available for end-user reporting using a number of different tools, including Redshift Spectrum and Amazon Athena.

unload ('SELECT * FROM weekly_tbl WHERE dataset_week = <<current week>>’) TO 's3:// <<S3 Bucket>>/datalake/weekly/20170526/' iam_role 'arn:aws:iam::0123456789012:role/MyRedshiftRole';

Summary

Amazon Redshift lets you easily operate petabyte-scale data warehouses on the cloud. This post summarized the best practices for operating scalable ETL natively within Amazon Redshift. I demonstrated efficient ways to ingest and transform data, along with close monitoring. I also demonstrated the best practices being used in a typical sample ETL workload to transform the data into Amazon Redshift.

If you have questions or suggestions, please comment below.

 


About the Author

Thiyagarajan Arumugam is a Big Data Solutions Architect at Amazon Web Services and designs customer architectures to process data at scale. Prior to AWS, he built data warehouse solutions at Amazon.com. In his free time, he enjoys all outdoor sports and practices the Indian classical drum mridangam.