Tag Archives: Amazon SNS

Managing Amazon SNS Subscription Attributes with AWS CloudFormation

Post Syndicated from Rachel Richardson original https://aws.amazon.com/blogs/compute/managing-amazon-sns-subscription-attributes-with-aws-cloudformation/

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

Amazon SNS is a fully managed pub/sub messaging and event-driven computing service that can decouple distributed systems and microservices. By default, when your publisher system posts a message to an Amazon SNS topic, all systems subscribed to the topic receive a copy of the message. By using Amazon SNS subscription attributes, you can customize this default behavior and make Amazon SNS fit your use cases even more naturally. The available set of Amazon SNS subscription attributes includes FilterPolicy, DeliveryPolicy, and RawMessageDelivery.

You can manually manage your Amazon SNS subscription attributes via the AWS Management Console or programmatically via AWS Development Tools (SDK and AWS CLI). Now you can automate their provisioning via AWS CloudFormation templates as well. AWS CloudFormation lets you use a simple text file to model and provision all the Amazon SNS resources for your messaging use cases, across AWS Regions and accounts, in an automated and secure manner.

The following sections describe how you can simultaneously create Amazon SNS subscriptions and set their attributes via AWS CloudFormation templates.

Setting the FilterPolicy attribute

The FilterPolicy attribute is valid in the context of message filtering, regardless of the delivery protocol, and defines which type of message the subscriber expects to receive from the topic. Hence, by applying the FilterPolicy attribute, you can offload the message-filtering logic from subscribers and the message-routing logic from publishers.

To set the FilterPolicy attribute in your AWS CloudFormation template, use the syntax in the following JSON snippet. This snippet creates an Amazon SNS subscription whose endpoint is an AWS Lambda function. Simultaneously, this code also sets a subscription filter policy that matches messages carrying an attribute whose key is “pet” and value is either “dog” or “cat.”

{
   "Resources": {
      "mySubscription": {
         "Type" : "AWS::SNS::Subscription",
         "Properties" : {
            "Protocol": "lambda",
            "Endpoint": "arn:aws:lambda:us-east-1:000000000000:function:SavePet",
            "TopicArn": "arn:aws:sns:us-east-1:000000000000:PetTopic",
            "FilterPolicy": {
               "pet": ["dog", "cat"]
            }
         }
      }
   }
}

Setting the DeliveryPolicy attribute

The DeliveryPolicy attribute is valid in the context of message delivery to HTTP endpoints and defines a delivery-retry policy. By applying the DeliveryPolicy attribute, you can control the maximum number of retries the subscriber expects, the time delay between each retry, and the backoff function. You should fine-tune these values based on the traffic volume your subscribing HTTP server can handle.

To set the DeliveryPolicy attribute in your AWS CloudFormation template, use the syntax in the following JSON snippet. This snippet creates an Amazon SNS subscription whose endpoint is an HTTP address. The code also sets a delivery policy capped at 10 retries for this subscription, with a linear backoff function.

{
   "Resources": {
      "mySubscription": {
         "Type" : "AWS::SNS::Subscription",
         "Properties" : {
            "Protocol": "https",
            "Endpoint": "https://api.myendpoint.ca/pets",
            "TopicArn": "arn:aws:sns:us-east-1:000000000000:PetTopic",
            "DeliveryPolicy": {
               "healthyRetryPolicy": {
                  "numRetries": 10,
                  "minDelayTarget": 10,
                  "maxDelayTarget": 30,
                  "numMinDelayRetries": 3,
                  "numMaxDelayRetries": 7,
                  "numNoDelayRetries": 0,
                  "backoffFunction": "linear"
               }
            }
         }
      }
   }
}

Setting the RawMessageDelivery attribute

The RawMessageDelivery attribute is valid in the context of message delivery to Amazon SQS queues and HTTP endpoints. This Boolean attribute eliminates the need for the subscriber to process the JSON formatting that is created by default to decorate all published messages with Amazon SNS metadata. When you set RawMessageDelivery to true, you get two outcomes. First, your message is delivered as is, with no metadata added. Second, your message attributes propagate from Amazon SNS to Amazon SQS, when the subscribing endpoint is an Amazon SQS queue.

To set the RawMessageDelivery attribute in your AWS CloudFormation template, use the syntax in the following JSON snippet. This snippet creates an Amazon SNS subscription whose endpoint is an Amazon SQS queue. This code also enables raw message delivery for the subscription, which prevents Amazon SNS metadata from being added to the message payload.

{
   "Resources": {
      "mySubscription": {
         "Type" : "AWS::SNS::Subscription",
         "Properties" : {
            "Protocol": "https",
            "Endpoint": "https://api.myendpoint.ca/pets",
            "TopicArn": "arn:aws:sns:us-east-1:000000000000:PetTopic",
            "DeliveryPolicy": {
               "healthyRetryPolicy": {
                  "numRetries": 10,
                  "minDelayTarget": 10,
                  "maxDelayTarget": 30,
                  "numMinDelayRetries": 3,
                  "numMaxDelayRetries": 7,
                  "numNoDelayRetries": 0,
                  "backoffFunction": "linear"
               }
            }
         }
      }
   }
}

Applying subscription attributes in a use case

Here’s how everything comes together. The following example is based on a car dealer company, which operates with the following distributed systems hosted on Amazon EC2 instances:

  • Car-Dealer-System – Front-office system that takes orders placed by car buyers
  • ERP-System – Enterprise resource planning, the back-office system that handles finance, accounting, human resources, and related business activities
  • CRM-System – Customer relationship management, the back-office system responsible for storing car buyers’ profile information and running sales workflows
  • SCM-System – Supply chain management, the back-office system that handles inventory tracking and demand forecast and planning

 

Whenever an order is placed in the car dealer system, this event is broadcasted to all back-office systems interested in this type of event. As shown in the preceding diagram, the company applied AWS Messaging services to decouple their distributed systems, promoting more scalability and maintainability for their architecture. The queues and topic used are the following:

  • Car-Sales – Amazon SNS topic that receives messages from the car dealer system. All orders placed by car buyers are published to this topic, then delivered to subscribers (two Amazon SQS queues and one HTTP endpoint).
  • ERP-Integration – Amazon SQS queue that feeds the ERP system with orders published by the car dealer system. The ERP pulls messages from this queue to track revenue and trigger related bookkeeping processes.
  • CRM-Integration – Amazon SQS queue that feeds the CRM system with orders published by the car dealer system. The CRM pulls messages from this queue to track car buyers’ interests and update sales workflows.

The company created the following three Amazon SNS subscriptions:

  • The first subscription refers to the ERP-Integration queue. This subscription has the RawMessageDelivery attribute set to true. Hence, no metadata is added to the message payload, and message attributes are propagated from Amazon SNS to Amazon SQS.
  • The second subscription refers to the CRM-Integration queue. Like the first subscription, this one also has the RawMessageDelivery attribute set to true. Additionally, it has the FilterPolicy attribute set to {“buyer-class”: [“vip”]}. This policy defines that only orders placed by VIP buyers are managed in the CRM system, and orders from other buyers are filtered out.
  • The third subscription points to the HTTP endpoint that serves the SCM-System. Unlike ERP and CRM, the SCM system provides its own HTTP API. Therefore, its HTTP endpoint was subscribed to the topic directly without a queue in between. This subscription has a DeliveryPolicy that caps the number of retries to 20, with exponential back-off function.

The company didn’t want to create all these resources manually, though. They wanted to turn this infrastructure into versionable code, and the ability to quickly spin up and tear down this infrastructure in an automated manner. Therefore, they created an AWS CloudFormation template to manage these AWS messaging resources: Amazon SNS topic, Amazon SNS subscriptions, Amazon SNS subscription attributes, and Amazon SQS queues.

Executing the AWS CloudFormation template

Now you’re ready to execute this AWS CloudFormation template yourself. To bootstrap this architecture in your AWS account:

    1. Download the sample AWS CloudFormation template from the repository.
    2. Go to the AWS CloudFormation console.
    3. Choose Create Stack.
    4. For Select Template, choose to upload a template to Amazon S3, and choose Browse.
    5. Select the template you downloaded and choose Next.
    6. For Specify Details:
      • Enter the following stack name: Car-Dealer-Stack.
      • Enter the HTTP endpoint to be subscribed to your topic. If you don’t have an HTTP endpoint, create a temp one.
      • Choose Next.
    7. For Options, choose Next.
    8. For Review, choose Create.
    9. Wait until your stack creation process is complete.

Now that all the infrastructure is in place, verify the Amazon SNS subscriptions attributes set by the AWS CloudFormation template as follows:

  1. Go to the Amazon SNS console.
  2. Choose Topics and then select the ARN associated with Car-Sales.
  3. Verify the first subscription:
    • Select the subscription related to ERP-Integration (Amazon SQS protocol).
    • Choose Other subscription actions and then choose Edit subscription attributes.
    • Note that raw message delivery is enabled, and choose Cancel to go back.
  4. Verify the second subscription:
    • Select the subscription related to CRM-Integration (Amazon SQS protocol).
    • Choose Other subscription actions and then choose Edit subscription attributes.
    • Note that raw message delivery is enabled and then choose Cancel to go back.
    • Choose Other subscription actions and then choose Edit subscription filter policy.
    • Note that the filter policy is set, and then choose Cancel to go back
  5. Confirm the third subscription.
  6. Verify the third subscription:
    • Select the subscription related to SCM-System (HTTP protocol).
    • Choose Other subscription actions and then choose Edit subscription delivery policy.
    •  Choose Advanced view.
    • Note that an exponential delivery retry policy is set, and then choose Cancel to go back.

Now that you have verified all subscription attributes, you can delete your AWS CloudFormation stack as follows:

  1. Go to the AWS CloudFormation console.
  2. In the list of stacks, select Car-Dealer-Stack.
  3. Choose Actions, choose Delete Stack, and then choose Yes Delete.
  4. Wait for the stack deletion process to complete.

That’s it! At this point, you have deleted all Amazon SNS and Amazon SQS resources created in this exercise from your AWS account.

Summary

AWS CloudFormation templates enable the simultaneous creation of Amazon SNS subscriptions and their attributes (such as FilterPolicy, DeliveryPolicy, and RawMessageDelivery) in an automated and secure manner. AWS CloudFormation support for Amazon SNS subscription attributes is available now in all AWS Regions.

For information about pricing, see AWS CloudFormation Pricing. For more information on setting up Amazon SNS resources via AWS CloudFormation templates, see:

Powering HIPAA-compliant workloads using AWS Serverless technologies

Post Syndicated from Chris Munns original https://aws.amazon.com/blogs/compute/powering-hipaa-compliant-workloads-using-aws-serverless-technologies/

This post courtesy of Mayank Thakkar, AWS Senior Solutions Architect

Serverless computing refers to an architecture discipline that allows you to build and run applications or services without thinking about servers. You can focus on your applications, without worrying about provisioning, scaling, or managing any servers. You can use serverless architectures for nearly any type of application or backend service. AWS handles the heavy lifting around scaling, high availability, and running those workloads.

The AWS HIPAA program enables covered entities—and those business associates subject to the U.S. Health Insurance Portability and Accountability Act of 1996 (HIPAA)—to use the secure AWS environment to process, maintain, and store protected health information (PHI). Based on customer feedback, AWS is trying to add more services to the HIPAA program, including serverless technologies.

AWS recently announced that AWS Step Functions has achieved HIPAA-eligibility status and has been added to the AWS Business Associate Addendum (BAA), adding to a growing list of HIPAA-eligible services. The BAA is an AWS contract that is required under HIPAA rules to ensure that AWS appropriately safeguards PHI. The BAA also serves to clarify and limit, as appropriate, the permissible uses and disclosures of PHI by AWS, based on the relationship between AWS and customers and the activities or services being performed by AWS.

Along with HIPAA eligibility for most of the rest of the serverless platform at AWS, Step Functions inclusion is a major win for organizations looking to process PHI using serverless technologies, opening up numerous new use cases and patterns. You can still use non-eligible services to orchestrate the storage, transmission, and processing of the metadata around PHI, but not the PHI itself.

In this post, I examine some common serverless use cases that I see in the healthcare and life sciences industry and show how AWS Serverless can be used to build powerful, cost-efficient, HIPAA-eligible architectures.

Provider directory web application

Running HIPAA-compliant web applications (like provider directories) on AWS is a common use case in the healthcare industry. Healthcare providers are often looking for ways to build and run applications and services without thinking about servers. They are also looking for ways to provide the most cost-effective and scalable delivery of secure health-related information to members, providers, and partners worldwide.

Unpredictable access patterns and spiky workloads often force organizations to provision for peak in these cases, and they end up paying for idle capacity. AWS Auto Scaling solves this challenge to a great extent but you still have to manage and maintain the underlying servers from a patching, high availability, and scaling perspective. AWS Lambda (along with other serverless technologies from AWS) removes this constraint.

The above architecture shows a serverless way to host a customer-facing website, with Amazon S3 being used for hosting static files (.js, .css, images, and so on). If your website is based on client-side technologies, you can eliminate the need to run a web server farm. In addition, you can use S3 features like server-side encryption and bucket access policies to lock down access to the content.

Using Amazon CloudFront, a global content delivery network, with S3 origins can bring your content closer to the end user and cut down S3 access costs, by caching the content at the edge. In addition, using AWS [email protected] gives you an ability to bring and execute your own code to customize the content that CloudFront delivers. That significantly reduces latency and improves the end user experience while maintaining the same Lambda development model. Some common examples include checking cookies, inspecting headers or authorization tokens, rewriting URLs, and making calls to external resources to confirm user credentials and generate HTTP responses.

You can power the APIs needed for your client application by using Amazon API Gateway, which takes care of creating, publishing, maintaining, monitoring, and securing APIs at any scale. API Gateway also provides robust ways to provide traffic management, authorization and access control, monitoring, API version management, and the other tasks involved in accepting and processing up to hundreds of thousands of concurrent API calls. This allows you to focus on your business logic. Direct, secure, and authenticated integration with Lambda functions allows this serverless architecture to scale up and down seamlessly with incoming traffic.

The CloudFront integration with AWS WAF provides a reliable way to protect your application against common web exploits that could affect application availability, compromise security, or consume excessive resources.

API Gateway can integrate directly with Lambda, which by default can access the public resources. Lambda functions can be configured to access your Amazon VPC resources as well. If you have extended your data center to AWS using AWS Direct Connect or a VPN connection, Lambda can access your on-premises resources, with the traffic flowing over your VPN connection (or Direct Connect) instead of the public internet.

All the services mentioned above (except Amazon EC2) are fully managed by AWS in terms of high availability, scaling, provisioning, and maintenance, giving you a cost-effective way to host your web applications. It’s pay-as-you-go vs. pay-as-you-provision. Spikes in demand, typically encountered during the enrollment season, are handled gracefully, with these services scaling automatically to meet demand and then scale down. You get to keep your costs in control.

All AWS services referenced in the above architecture are HIPAA-eligible, thus enabling you to store, process, and transmit PHI, as long as it complies with the BAA.

Medical device telemetry (ingesting data @ scale)

The ever-increasing presence of IoT devices in the healthcare industry has created the challenges of ingesting this data at scale and making it available for processing as soon as it is produced. Processing this data in real time (or near-real time) is key to delivering urgent care to patients.

The infinite scalability (theoretical) along with low startup times offered by Lambda makes it a great candidate for these kinds of use cases. Balancing ballooning healthcare costs and timely delivery of care is a never-ending challenge. With subsecond billing and no charge for non-execution, Lambda becomes the best choice for AWS customers.

These end-user medical devices emit a lot of telemetry data, which requires constant analysis and real-time tracking and updating. For example, devices like infusion pumps, personal use dialysis machines, and so on require tracking and alerting of device consumables and calibration status. They also require updates for these settings. Consider the following architecture:

Typically, these devices are connected to an edge node or collector, which provides sufficient computing resources to authenticate itself to AWS and start streaming data to Amazon Kinesis Streams. The collector uses the Kinesis Producer Library to simplify high throughput to a Kinesis data stream. You can also use the server-side encryption feature, supported by Kinesis Streams, to achieve encryption-at-rest. Kinesis provides a scalable, highly available way to achieve loose coupling between data-producing (medical devices) and data-consuming (Lambda) layers.

After the data is transported via Kinesis, Lambda can then be used to process this data in real time, storing derived insights in Amazon DynamoDB, which can then power a near-real time health dashboard. Caregivers can access this real-time data to provide timely care and manage device settings.

End-user medical devices, via the edge node, can also connect to and poll an API hosted on API Gateway to check for calibration settings, firmware updates, and so on. The modifications can be easily updated by admins, providing a scalable way to manage these devices.

For historical analysis and pattern prediction, the staged data (stored in S3), can be processed in batches. Use AWS Batch, Amazon EMR, or any custom logic running on a fleet of Amazon EC2 instances to gain actionable insights. Lambda can also be used to process data in a MapReduce fashion, as detailed in the Ad Hoc Big Data Processing Made Simple with Serverless MapReduce post.

You can also build high-throughput batch workflows or orchestrate Apache Spark applications using Step Functions, as detailed in the Orchestrate Apache Spark applications using AWS Step Functions and Apache Livy post. These insights can then be used to calibrate the medical devices to achieve effective outcomes.

Use Lambda to load data into Amazon Redshift, a cost-effective, petabyte-scale data warehouse offering. One of my colleagues, Ian Meyers, pointed this out in his Zero-Administration Amazon Redshift Database Loader post.

Mobile diagnostics

Another use case that I see is using mobile devices to provide diagnostic care in out-patient settings. These environments typically lack the robust IT infrastructure that clinics and hospitals can provide, and often are subjected to intermittent internet connectivity as well. Various biosensors (otoscopes, thermometers, heart rate monitors, and so on) can easily talk to smartphones, which can then act as aggregators and analyzers before forwarding the data to a central processing system. After the data is in the system, caregivers and practitioners can then view and act on the data.

In the above diagram, an application running on a mobile device (iOS or Android) talks to various biosensors and collects diagnostic data. Using AWS mobile SDKs along with Amazon Cognito, these smart devices can authenticate themselves to AWS and access the APIs hosted on API Gateway. Amazon Cognito also offers data synchronization across various mobile devices, which helps you to build “offline” features in your mobile application. Amazon Cognito Sync resolves conflicts and intermittent network connectivity, enabling you to focus on delivering great app experiences instead of creating and managing a user data sync solution.

You can also use CloudFront and [email protected], as detailed in the first use case of this post, to cache content at edge locations and provide some light processing closer to your end users.

Lambda acts as a middle tier, processing the CRUD operations on the incoming data and storing it in DynamoDB, which is again exposed to caregivers through another set of Lambda functions and API Gateway. Caregivers can access the information through a browser-based interface, with Lambda processing the middle-tier application logic. They can view the historical data, compare it with fresh data coming in, and make corrections. Caregivers can also react to incoming data and issue alerts, which are delivered securely to the smart device through Amazon SNS.

Also, by using DynamoDB Streams and its integration with Lambda, you can implement Lambda functions that react to data modifications in DynamoDB tables (and hence, incoming device data). This gives you a way to codify common reactions to incoming data, in near-real time.

Lambda ecosystem

As I discussed in the above use cases, Lambda is a powerful, event-driven, stateless, on-demand compute platform offering scalability, agility, security, and reliability, along with a fine-grained cost structure.

For some organizations, migrating from a traditional programing model to a microservices-driven model can be a steep curve. Also, to build and maintain complex applications using Lambda, you need a vast array of tools, all the way from local debugging support to complex application performance monitoring tools. The following list of tools and services can assist you in building world-class applications with minimal effort:

  • AWS X-Ray is a distributed tracing system that allows developers to analyze and debug production for distributed applications, such as those built using a microservices (Lambda) architecture. AWS X-Ray was recently added to the AWS BAA, opening the doors for processing PHI workloads.
  • AWS Step Functions helps build HIPAA-compliant complex workflows using Lambda. It provides a way to coordinate the components of distributed applications and Lambda functions using visual workflows.
  • AWS SAM provides a fast and easy way of deploying serverless applications. You can write simple templates to describe your functions and their event sources (API Gateway, S3, Kinesis, and so on). AWS recently relaunched the AWS SAM CLI, which allows you to create a local testing environment that simulates the AWS runtime environment for Lambda. It allows faster, iterative development of your Lambda functions by eliminating the need to redeploy your application package to the Lambda runtime.

For more details, see the Serverless Application Developer Tooling webpage.

Conclusion

There are numerous other health care and life science use cases that customers are implementing, using Lambda with other AWS services. AWS is committed to easing the effort of implementing health care solutions in the cloud. Making Lambda HIPAA-eligible is just another milestone in the journey. For more examples of use cases, see Serverless. For the latest list of HIPAA-eligible services, see HIPAA Eligible Services Reference.

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:

Use Slack ChatOps to Deploy Your Code – How to Integrate Your Pipeline in AWS CodePipeline with Your Slack Channel

Post Syndicated from Rumi Olsen original https://aws.amazon.com/blogs/devops/use-slack-chatops-to-deploy-your-code-how-to-integrate-your-pipeline-in-aws-codepipeline-with-your-slack-channel/

Slack is widely used by DevOps and development teams to communicate status. Typically, when a build has been tested and is ready to be promoted to a staging environment, a QA engineer or DevOps engineer kicks off the deployment. Using Slack in a ChatOps collaboration model, the promotion can be done in a single click from a Slack channel. And because the promotion happens through a Slack channel, the whole development team knows what’s happening without checking email.

In this blog post, I will show you how to integrate AWS services with a Slack application. I use an interactive message button and incoming webhook to promote a stage with a single click.

To follow along with the steps in this post, you’ll need a pipeline in AWS CodePipeline. If you don’t have a pipeline, the fastest way to create one for this use case is to use AWS CodeStar. Go to the AWS CodeStar console and select the Static Website template (shown in the screenshot). AWS CodeStar will create a pipeline with an AWS CodeCommit repository and an AWS CodeDeploy deployment for you. After the pipeline is created, you will need to add a manual approval stage.

You’ll also need to build a Slack app with webhooks and interactive components, write two Lambda functions, and create an API Gateway API and a SNS topic.

As you’ll see in the following diagram, when I make a change and merge a new feature into the master branch in AWS CodeCommit, the check-in kicks off my CI/CD pipeline in AWS CodePipeline. When CodePipeline reaches the approval stage, it sends a notification to Amazon SNS, which triggers an AWS Lambda function (ApprovalRequester).

The Slack channel receives a prompt that looks like the following screenshot. When I click Yes to approve the build promotion, the approval result is sent to CodePipeline through API Gateway and Lambda (ApprovalHandler). The pipeline continues on to deploy the build to the next environment.

Create a Slack app

For App Name, type a name for your app. For Development Slack Workspace, choose the name of your workspace. You’ll see in the following screenshot that my workspace is AWS ChatOps.

After the Slack application has been created, you will see the Basic Information page, where you can create incoming webhooks and enable interactive components.

To add incoming webhooks:

  1. Under Add features and functionality, choose Incoming Webhooks. Turn the feature on by selecting Off, as shown in the following screenshot.
  2. Now that the feature is turned on, choose Add New Webhook to Workspace. In the process of creating the webhook, Slack lets you choose the channel where messages will be posted.
  3. After the webhook has been created, you’ll see its URL. You will use this URL when you create the Lambda function.

If you followed the steps in the post, the pipeline should look like the following.

Write the Lambda function for approval requests

This Lambda function is invoked by the SNS notification. It sends a request that consists of an interactive message button to the incoming webhook you created earlier.  The following sample code sends the request to the incoming webhook. WEBHOOK_URL and SLACK_CHANNEL are the environment variables that hold values of the webhook URL that you created and the Slack channel where you want the interactive message button to appear.

# This function is invoked via SNS when the CodePipeline manual approval action starts.
# It will take the details from this approval notification and sent an interactive message to Slack that allows users to approve or cancel the deployment.

import os
import json
import logging
import urllib.parse

from base64 import b64decode
from urllib.request import Request, urlopen
from urllib.error import URLError, HTTPError

# This is passed as a plain-text environment variable for ease of demonstration.
# Consider encrypting the value with KMS or use an encrypted parameter in Parameter Store for production deployments.
SLACK_WEBHOOK_URL = os.environ['SLACK_WEBHOOK_URL']
SLACK_CHANNEL = os.environ['SLACK_CHANNEL']

logger = logging.getLogger()
logger.setLevel(logging.INFO)

def lambda_handler(event, context):
    print("Received event: " + json.dumps(event, indent=2))
    message = event["Records"][0]["Sns"]["Message"]
    
    data = json.loads(message) 
    token = data["approval"]["token"]
    codepipeline_name = data["approval"]["pipelineName"]
    
    slack_message = {
        "channel": SLACK_CHANNEL,
        "text": "Would you like to promote the build to production?",
        "attachments": [
            {
                "text": "Yes to deploy your build to production",
                "fallback": "You are unable to promote a build",
                "callback_id": "wopr_game",
                "color": "#3AA3E3",
                "attachment_type": "default",
                "actions": [
                    {
                        "name": "deployment",
                        "text": "Yes",
                        "style": "danger",
                        "type": "button",
                        "value": json.dumps({"approve": True, "codePipelineToken": token, "codePipelineName": codepipeline_name}),
                        "confirm": {
                            "title": "Are you sure?",
                            "text": "This will deploy the build to production",
                            "ok_text": "Yes",
                            "dismiss_text": "No"
                        }
                    },
                    {
                        "name": "deployment",
                        "text": "No",
                        "type": "button",
                        "value": json.dumps({"approve": False, "codePipelineToken": token, "codePipelineName": codepipeline_name})
                    }  
                ]
            }
        ]
    }

    req = Request(SLACK_WEBHOOK_URL, json.dumps(slack_message).encode('utf-8'))

    response = urlopen(req)
    response.read()
    
    return None

 

Create a SNS topic

Create a topic and then create a subscription that invokes the ApprovalRequester Lambda function. You can configure the manual approval action in the pipeline to send a message to this SNS topic when an approval action is required. When the pipeline reaches the approval stage, it sends a notification to this SNS topic. SNS publishes a notification to all of the subscribed endpoints. In this case, the Lambda function is the endpoint. Therefore, it invokes and executes the Lambda function. For information about how to create a SNS topic, see Create a Topic in the Amazon SNS Developer Guide.

Write the Lambda function for handling the interactive message button

This Lambda function is invoked by API Gateway. It receives the result of the interactive message button whether or not the build promotion was approved. If approved, an API call is made to CodePipeline to promote the build to the next environment. If not approved, the pipeline stops and does not move to the next stage.

The Lambda function code might look like the following. SLACK_VERIFICATION_TOKEN is the environment variable that contains your Slack verification token. You can find your verification token under Basic Information on Slack manage app page. When you scroll down, you will see App Credential. Verification token is found under the section.

# This function is triggered via API Gateway when a user acts on the Slack interactive message sent by approval_requester.py.

from urllib.parse import parse_qs
import json
import os
import boto3

SLACK_VERIFICATION_TOKEN = os.environ['SLACK_VERIFICATION_TOKEN']

#Triggered by API Gateway
#It kicks off a particular CodePipeline project
def lambda_handler(event, context):
	#print("Received event: " + json.dumps(event, indent=2))
	body = parse_qs(event['body'])
	payload = json.loads(body['payload'][0])

	# Validate Slack token
	if SLACK_VERIFICATION_TOKEN == payload['token']:
		send_slack_message(json.loads(payload['actions'][0]['value']))
		
		# This will replace the interactive message with a simple text response.
		# You can implement a more complex message update if you would like.
		return  {
			"isBase64Encoded": "false",
			"statusCode": 200,
			"body": "{\"text\": \"The approval has been processed\"}"
		}
	else:
		return  {
			"isBase64Encoded": "false",
			"statusCode": 403,
			"body": "{\"error\": \"This request does not include a vailid verification token.\"}"
		}


def send_slack_message(action_details):
	codepipeline_status = "Approved" if action_details["approve"] else "Rejected"
	codepipeline_name = action_details["codePipelineName"]
	token = action_details["codePipelineToken"] 

	client = boto3.client('codepipeline')
	response_approval = client.put_approval_result(
							pipelineName=codepipeline_name,
							stageName='Approval',
							actionName='ApprovalOrDeny',
							result={'summary':'','status':codepipeline_status},
							token=token)
	print(response_approval)

 

Create the API Gateway API

  1. In the Amazon API Gateway console, create a resource called InteractiveMessageHandler.
  2. Create a POST method.
    • For Integration type, choose Lambda Function.
    • Select Use Lambda Proxy integration.
    • From Lambda Region, choose a region.
    • In Lambda Function, type a name for your function.
  3.  Deploy to a stage.

For more information, see Getting Started with Amazon API Gateway in the Amazon API Developer Guide.

Now go back to your Slack application and enable interactive components.

To enable interactive components for the interactive message (Yes) button:

  1. Under Features, choose Interactive Components.
  2. Choose Enable Interactive Components.
  3. Type a request URL in the text box. Use the invoke URL in Amazon API Gateway that will be called when the approval button is clicked.

Now that all the pieces have been created, run the solution by checking in a code change to your CodeCommit repo. That will release the change through CodePipeline. When the CodePipeline comes to the approval stage, it will prompt to your Slack channel to see if you want to promote the build to your staging or production environment. Choose Yes and then see if your change was deployed to the environment.

Conclusion

That is it! You have now created a Slack ChatOps solution using AWS CodeCommit, AWS CodePipeline, AWS Lambda, Amazon API Gateway, and Amazon Simple Notification Service.

Now that you know how to do this Slack and CodePipeline integration, you can use the same method to interact with other AWS services using API Gateway and Lambda. You can also use Slack’s slash command to initiate an action from a Slack channel, rather than responding in the way demonstrated in this post.

The End of Google Cloud Messaging, and What it Means for Your Apps

Post Syndicated from Zach Barbitta original https://aws.amazon.com/blogs/messaging-and-targeting/the-end-of-google-cloud-messaging-and-what-it-means-for-your-apps/

On April 10, 2018, Google announced the deprecation of its Google Cloud Messaging (GCM) platform. Specifically, the GCM server and client APIs are deprecated and will be removed as soon as April 11, 2019.  What does this mean for you and your applications that use Amazon Simple Notification Service (Amazon SNS) or Amazon Pinpoint?

First, nothing will break now or after April 11, 2019. GCM device tokens are completely interchangeable with the newer Firebase Cloud Messaging (FCM) device tokens. If you have existing GCM tokens, you’ll still be able to use them to send notifications. This statement is also true for GCM tokens that you generate in the future.

On the back end, we’ve already migrated Amazon SNS and Amazon Pinpoint to the server endpoint for FCM (https://fcm.googleapis.com/fcm/send). As a developer, you don’t need to make any changes as a result of this deprecation.

We created the following mini-FAQ to address some of the questions you may have as a developer who uses Amazon SNS or Amazon Pinpoint.

If I migrate to FCM from GCM, can I still use Amazon Pinpoint and Amazon SNS?

Yes. Your ability to connect to your applications and send messages through both Amazon SNS and Amazon Pinpoint doesn’t change. We’ll update the documentation for Amazon SNS and Amazon Pinpoint soon to reflect these changes.

If I don’t migrate to FCM from GCM, can I still use Amazon Pinpoint and Amazon SNS?

Yes. If you do nothing, your existing credentials and GCM tokens will still be valid. All applications that you previously set up to use Amazon Pinpoint or Amazon SNS will continue to work normally. When you call the API for Amazon Pinpoint or Amazon SNS, we initiate a request to the FCM server endpoint directly.

What are the differences between Amazon SNS and Amazon Pinpoint?

Amazon SNS makes it easy for developers to set up, operate, and send notifications at scale, affordably and with a high degree of flexibility. Amazon Pinpoint has many of the same messaging capabilities as Amazon SNS, with the same levels of scalability and flexibility.

The main difference between the two services is that Amazon Pinpoint provides both transactional and targeted messaging capabilities. By using Amazon Pinpoint, marketers and developers can not only send transactional messages to their customers, but can also segment their audiences, create campaigns, and analyze both application and message metrics.

How do I migrate from GCM to FCM?

For more information about migrating from GCM to FCM, see Migrate a GCM Client App for Android to Firebase Cloud Messaging on the Google Developers site.

If you have any questions, please post them in the comments section, or in the Amazon Pinpoint or Amazon SNS forums.

Securing messages published to Amazon SNS with AWS PrivateLink

Post Syndicated from Otavio Ferreira original https://aws.amazon.com/blogs/security/securing-messages-published-to-amazon-sns-with-aws-privatelink/

Amazon Simple Notification Service (SNS) now supports VPC Endpoints (VPCE) via AWS PrivateLink. You can use VPC Endpoints to privately publish messages to SNS topics, from an Amazon Virtual Private Cloud (VPC), without traversing the public internet. When you use AWS PrivateLink, you don’t need to set up an Internet Gateway (IGW), Network Address Translation (NAT) device, or Virtual Private Network (VPN) connection. You don’t need to use public IP addresses, either.

VPC Endpoints doesn’t require code changes and can bring additional security to Pub/Sub Messaging use cases that rely on SNS. VPC Endpoints helps promote data privacy and is aligned with assurance programs, including the Health Insurance Portability and Accountability Act (HIPAA), FedRAMP, and others discussed below.

VPC Endpoints for SNS in action

Here’s how VPC Endpoints for SNS works. The following example is based on a banking system that processes mortgage applications. This banking system, which has been deployed to a VPC, publishes each mortgage application to an SNS topic. The SNS topic then fans out the mortgage application message to two subscribing AWS Lambda functions:

  • Save-Mortgage-Application stores the application in an Amazon DynamoDB table. As the mortgage application contains personally identifiable information (PII), the message must not traverse the public internet.
  • Save-Credit-Report checks the applicant’s credit history against an external Credit Reporting Agency (CRA), then stores the final credit report in an Amazon S3 bucket.

The following diagram depicts the underlying architecture for this banking system:
 
Diagram depicting the architecture for the example banking system
 
To protect applicants’ data, the financial institution responsible for developing this banking system needed a mechanism to prevent PII data from traversing the internet when publishing mortgage applications from their VPC to the SNS topic. Therefore, they created a VPC endpoint to enable their publisher Amazon EC2 instance to privately connect to the SNS API. As shown in the diagram, when the VPC endpoint is created, an Elastic Network Interface (ENI) is automatically placed in the same VPC subnet as the publisher EC2 instance. This ENI exposes a private IP address that is used as the entry point for traffic destined to SNS. This ensures that traffic between the VPC and SNS doesn’t leave the Amazon network.

Set up VPC Endpoints for SNS

The process for creating a VPC endpoint to privately connect to SNS doesn’t require code changes: access the VPC Management Console, navigate to the Endpoints section, and create a new Endpoint. Three attributes are required:

  • The SNS service name.
  • The VPC and Availability Zones (AZs) from which you’ll publish your messages.
  • The Security Group (SG) to be associated with the endpoint network interface. The Security Group controls the traffic to the endpoint network interface from resources in your VPC. If you don’t specify a Security Group, the default Security Group for your VPC will be associated.

Help ensure your security and compliance

SNS can support messaging use cases in regulated market segments, such as healthcare provider systems subject to the Health Insurance Portability and Accountability Act (HIPAA) and financial systems subject to the Payment Card Industry Data Security Standard (PCI DSS), and is also in-scope with the following Assurance Programs:

The SNS API is served through HTTP Secure (HTTPS), and encrypts all messages in transit with Transport Layer Security (TLS) certificates issued by Amazon Trust Services (ATS). The certificates verify the identity of the SNS API server when encrypted connections are established. The certificates help establish proof that your SNS API client (SDK, CLI) is communicating securely with the SNS API server. A Certificate Authority (CA) issues the certificate to a specific domain. Hence, when a domain presents a certificate that’s issued by a trusted CA, the SNS API client knows it’s safe to make the connection.

Summary

VPC Endpoints can increase the security of your pub/sub messaging use cases by allowing you to publish messages to SNS topics, from instances in your VPC, without traversing the internet. Setting up VPC Endpoints for SNS doesn’t require any code changes because the SNS API address remains the same.

VPC Endpoints for SNS is now available in all AWS Regions where AWS PrivateLink is available. For information on pricing and regional availability, visit the VPC pricing page.
For more information and on-boarding, see Publishing to Amazon SNS Topics from Amazon Virtual Private Cloud in the SNS documentation.

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

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Message Filtering Operators for Numeric Matching, Prefix Matching, and Blacklisting in Amazon SNS

Post Syndicated from Christie Gifrin original https://aws.amazon.com/blogs/compute/message-filtering-operators-for-numeric-matching-prefix-matching-and-blacklisting-in-amazon-sns/

This blog was contributed by Otavio Ferreira, Software Development Manager for Amazon SNS

Message filtering simplifies the overall pub/sub messaging architecture by offloading message filtering logic from subscribers, as well as message routing logic from publishers. The initial launch of message filtering provided a basic operator that was based on exact string comparison. For more information, see Simplify Your Pub/Sub Messaging with Amazon SNS Message Filtering.

Today, AWS is announcing an additional set of filtering operators that bring even more power and flexibility to your pub/sub messaging use cases.

Message filtering operators

Amazon SNS now supports both numeric and string matching. Specifically, string matching operators allow for exact, prefix, and “anything-but” comparisons, while numeric matching operators allow for exact and range comparisons, as outlined below. Numeric matching operators work for values between -10e9 and +10e9 inclusive, with five digits of accuracy right of the decimal point.

  • Exact matching on string values (Whitelisting): Subscription filter policy   {"sport": ["rugby"]} matches message attribute {"sport": "rugby"} only.
  • Anything-but matching on string values (Blacklisting): Subscription filter policy {"sport": [{"anything-but": "rugby"}]} matches message attributes such as {"sport": "baseball"} and {"sport": "basketball"} and {"sport": "football"} but not {"sport": "rugby"}
  • Prefix matching on string values: Subscription filter policy {"sport": [{"prefix": "bas"}]} matches message attributes such as {"sport": "baseball"} and {"sport": "basketball"}
  • Exact matching on numeric values: Subscription filter policy {"balance": [{"numeric": ["=", 301.5]}]} matches message attributes {"balance": 301.500} and {"balance": 3.015e2}
  • Range matching on numeric values: Subscription filter policy {"balance": [{"numeric": ["<", 0]}]} matches negative numbers only, and {"balance": [{"numeric": [">", 0, "<=", 150]}]} matches any positive number up to 150.

As usual, you may apply the “AND” logic by appending multiple keys in the subscription filter policy, and the “OR” logic by appending multiple values for the same key, as follows:

  • AND logic: Subscription filter policy {"sport": ["rugby"], "language": ["English"]} matches only messages that carry both attributes {"sport": "rugby"} and {"language": "English"}
  • OR logic: Subscription filter policy {"sport": ["rugby", "football"]} matches messages that carry either the attribute {"sport": "rugby"} or {"sport": "football"}

Message filtering operators in action

Here’s how this new set of filtering operators works. The following example is based on a pharmaceutical company that develops, produces, and markets a variety of prescription drugs, with research labs located in Asia Pacific and Europe. The company built an internal procurement system to manage the purchasing of lab supplies (for example, chemicals and utensils), office supplies (for example, paper, folders, and markers) and tech supplies (for example, laptops, monitors, and printers) from global suppliers.

This distributed system is composed of the four following subsystems:

  • A requisition system that presents the catalog of products from suppliers, and takes orders from buyers
  • An approval system for orders targeted to Asia Pacific labs
  • Another approval system for orders targeted to European labs
  • A fulfillment system that integrates with shipping partners

As shown in the following diagram, the company leverages AWS messaging services to integrate these distributed systems.

  • Firstly, an SNS topic named “Orders” was created to take all orders placed by buyers on the requisition system.
  • Secondly, two Amazon SQS queues, named “Lab-Orders-AP” and “Lab-Orders-EU” (for Asia Pacific and Europe respectively), were created to backlog orders that are up for review on the approval systems.
  • Lastly, an SQS queue named “Common-Orders” was created to backlog orders that aren’t related to lab supplies, which can already be picked up by shipping partners on the fulfillment system.

The company also uses AWS Lambda functions to automatically process lab supply orders that don’t require approval or which are invalid.

In this example, because different types of orders have been published to the SNS topic, the subscribing endpoints have had to set advanced filter policies on their SNS subscriptions, to have SNS automatically filter out orders they can’t deal with.

As depicted in the above diagram, the following five filter policies have been created:

  • The SNS subscription that points to the SQS queue “Lab-Orders-AP” sets a filter policy that matches lab supply orders, with a total value greater than $1,000, and that target Asia Pacific labs only. These more expensive transactions require an approver to review orders placed by buyers.
  • The SNS subscription that points to the SQS queue “Lab-Orders-EU” sets a filter policy that matches lab supply orders, also with a total value greater than $1,000, but that target European labs instead.
  • The SNS subscription that points to the Lambda function “Lab-Preapproved” sets a filter policy that only matches lab supply orders that aren’t as expensive, up to $1,000, regardless of their target lab location. These orders simply don’t require approval and can be automatically processed.
  • The SNS subscription that points to the Lambda function “Lab-Cancelled” sets a filter policy that only matches lab supply orders with total value of $0 (zero), regardless of their target lab location. These orders carry no actual items, obviously need neither approval nor fulfillment, and as such can be automatically canceled.
  • The SNS subscription that points to the SQS queue “Common-Orders” sets a filter policy that blacklists lab supply orders. Hence, this policy matches only office and tech supply orders, which have a more streamlined fulfillment process, and require no approval, regardless of price or target location.

After the company finished building this advanced pub/sub architecture, they were then able to launch their internal procurement system and allow buyers to begin placing orders. The diagram above shows six example orders published to the SNS topic. Each order contains message attributes that describe the order, and cause them to be filtered in a different manner, as follows:

  • Message #1 is a lab supply order, with a total value of $15,700 and targeting a research lab in Singapore. Because the value is greater than $1,000, and the location “Asia-Pacific-Southeast” matches the prefix “Asia-Pacific-“, this message matches the first SNS subscription and is delivered to SQS queue “Lab-Orders-AP”.
  • Message #2 is a lab supply order, with a total value of $1,833 and targeting a research lab in Ireland. Because the value is greater than $1,000, and the location “Europe-West” matches the prefix “Europe-“, this message matches the second SNS subscription and is delivered to SQS queue “Lab-Orders-EU”.
  • Message #3 is a lab supply order, with a total value of $415. Because the value is greater than $0 and less than $1,000, this message matches the third SNS subscription and is delivered to Lambda function “Lab-Preapproved”.
  • Message #4 is a lab supply order, but with a total value of $0. Therefore, it only matches the fourth SNS subscription, and is delivered to Lambda function “Lab-Cancelled”.
  • Messages #5 and #6 aren’t lab supply orders actually; one is an office supply order, and the other is a tech supply order. Therefore, they only match the fifth SNS subscription, and are both delivered to SQS queue “Common-Orders”.

Although each message only matched a single subscription, each was tested against the filter policy of every subscription in the topic. Hence, depending on which attributes are set on the incoming message, the message might actually match multiple subscriptions, and multiple deliveries will take place. Also, it is important to bear in mind that subscriptions with no filter policies catch every single message published to the topic, as a blank filter policy equates to a catch-all behavior.

Summary

Amazon SNS allows for both string and numeric filtering operators. As explained in this post, string operators allow for exact, prefix, and “anything-but” comparisons, while numeric operators allow for exact and range comparisons. These advanced filtering operators bring even more power and flexibility to your pub/sub messaging functionality and also allow you to simplify your architecture further by removing even more logic from your subscribers.

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). SNS filtering operators for numeric matching, prefix matching, and blacklisting are available now in all AWS Regions, for no extra charge.

To experiment with these new filtering operators yourself, and continue learning, try the 10-minute Tutorial Filter Messages Published to Topics. For more information, see Filtering Messages with Amazon SNS in the SNS documentation.

Troubleshooting event publishing issues in Amazon SES

Post Syndicated from Dustin Taylor original https://aws.amazon.com/blogs/ses/troubleshooting-event-publishing-issues-in-amazon-ses/

Over the past year, we’ve released several features that make it easier to track the metrics that are associated with your Amazon SES account. The first of these features, launched in November of last year, was event publishing.

Initially, event publishing let you capture basic metrics related to your email sending and publish them to other AWS services, such as Amazon CloudWatch and Amazon Kinesis Data Firehose. Some examples of these basic metrics include the number of emails that were sent and delivered, as well as the number that bounced or received complaints. A few months ago, we expanded this feature by adding engagement metrics—specifically, information about the number of emails that your customers opened or engaged with by clicking links.

As a former Cloud Support Engineer, I’ve seen Amazon SES customers do some amazing things with event publishing, but I’ve also seen some common issues. In this article, we look at some of these issues, and discuss the steps you can take to resolve them.

Before we begin

This post assumes that your Amazon SES account is already out of the sandbox, that you’ve verified an identity (such as an email address or domain), and that you have the necessary permissions to use Amazon SES and the service that you’ll publish event data to (such as Amazon SNS, CloudWatch, or Kinesis Data Firehose).

We also assume that you’re familiar with the process of creating configuration sets and specifying event destinations for those configuration sets. For more information, see Using Amazon SES Configuration Sets in the Amazon SES Developer Guide.

Amazon SNS event destinations

If you want to receive notifications when events occur—such as when recipients click a link in an email, or when they report an email as spam—you can use Amazon SNS as an event destination.

Occasionally, customers ask us why they’re not receiving notifications when they use an Amazon SNS topic as an event destination. One of the most common reasons for this issue is that they haven’t configured subscriptions for their Amazon SNS topic yet.

A single topic in Amazon SNS can have one or more subscriptions. When you subscribe to a topic, you tell that topic which endpoints (such as email addresses or mobile phone numbers) to contact when it receives a notification. If you haven’t set up any subscriptions, nothing will happen when an email event occurs.

For more information about setting up topics and subscriptions, see Getting Started in the Amazon SNS Developer Guide. For information about publishing Amazon SES events to Amazon SNS topics, see Set Up an Amazon SNS Event Destination for Amazon SES Event Publishing in the Amazon SES Developer Guide.

Kinesis Data Firehose event destinations

If you want to store your Amazon SES event data for the long term, choose Amazon Kinesis Data Firehose as a destination for Amazon SES events. With Kinesis Data Firehose, you can stream data to Amazon S3 or Amazon Redshift for storage and analysis.

The process of setting up Kinesis Data Firehose as an event destination is similar to the process for setting up Amazon SNS: you choose the types of events (such as deliveries, opens, clicks, or bounces) that you want to export, and the name of the Kinesis Data Firehose stream that you want to export to. However, there’s one important difference. When you set up a Kinesis Data Firehose event destination, you must also choose the IAM role that Amazon SES uses to send event data to Kinesis Data Firehose.

When you set up the Kinesis Data Firehose event destination, you can choose to have Amazon SES create the IAM role for you automatically. For many users, this is the best solution—it ensures that the IAM role has the appropriate permissions to move event data from Amazon SES to Kinesis Data Firehose.

Customers occasionally run into issues with the Kinesis Data Firehose event destination when they use an existing IAM role. If you use an existing IAM role, or create a new role for this purpose, make sure that the role includes the firehose:PutRecord and firehose:PutRecordBatch permissions. If the role doesn’t include these permissions, then the Amazon SES event data isn’t published to Kinesis Data Firehose. For more information, see Controlling Access with Amazon Kinesis Data Firehose in the Amazon Kinesis Data Firehose Developer Guide.

CloudWatch event destinations

By publishing your Amazon SES event data to Amazon CloudWatch, you can create dashboards that track your sending statistics in real time, as well as alarms that notify you when your event metrics reach certain thresholds.

The amount that you’re charged for using CloudWatch is based on several factors, including the number of metrics you use. In order to give you more control over the specific metrics you send to CloudWatch—and to help you avoid unexpected charges—you can limit the email sending events that are sent to CloudWatch.

When you choose CloudWatch as an event destination, you must choose a value source. The value source can be one of three options: a message tag, a link tag, or an email header. After you choose a value source, you then specify a name and a value. When you send an email using a configuration set that refers to a CloudWatch event destination, it only sends the metrics for that email to CloudWatch if the email contains the name and value that you specified as the value source. This requirement is commonly overlooked.

For example, assume that you chose Message Tag as the value source, and specified “CategoryId” as the dimension name and “31415” as the dimension value. When you want to send events for an email to CloudWatch, you must specify the name of the configuration set that uses the CloudWatch destination. You must also include a tag in your message. The name of the tag must be “CategoryId” and the value must be “31415”.

For more information about adding tags and email headers to your messages, see Send Email Using Amazon SES Event Publishing in the Amazon SES Developer Guide. For more information about adding tags to links, see Amazon SES Email Sending Metrics FAQs in the Amazon SES Developer Guide.

Troubleshooting event publishing for open and click data

Occasionally, customers ask why they’re not seeing open and click data for their emails. This issue most often occurs when the customer only sends text versions of their emails. Because of the way Amazon SES tracks open and click events, you can only see open and click data for emails that are sent as HTML. For more information about how Amazon SES modifies your emails when you enable open and click tracking, see Amazon SES Email Sending Metrics FAQs in the Amazon SES Developer Guide.

The process that you use to send HTML emails varies based on the email sending method you use. The Code Examples section of the Amazon SES Developer Guide contains examples of several methods of sending email by using the Amazon SES SMTP interface or an AWS SDK. All of the examples in this section include methods for sending HTML (as well as text-only) emails.

If you encounter any issues that weren’t covered in this post, please open a case in the Support Center and we’d be more than happy to assist.

Scale Your Web Application — One Step at a Time

Post Syndicated from Saurabh Shrivastava original https://aws.amazon.com/blogs/architecture/scale-your-web-application-one-step-at-a-time/

I often encounter people experiencing frustration as they attempt to scale their e-commerce or WordPress site—particularly around the cost and complexity related to scaling. When I talk to customers about their scaling plans, they often mention phrases such as horizontal scaling and microservices, but usually people aren’t sure about how to dive in and effectively scale their sites.

Now let’s talk about different scaling options. For instance if your current workload is in a traditional data center, you can leverage the cloud for your on-premises solution. This way you can scale to achieve greater efficiency with less cost. It’s not necessary to set up a whole powerhouse to light a few bulbs. If your workload is already in the cloud, you can use one of the available out-of-the-box options.

Designing your API in microservices and adding horizontal scaling might seem like the best choice, unless your web application is already running in an on-premises environment and you’ll need to quickly scale it because of unexpected large spikes in web traffic.

So how to handle this situation? Take things one step at a time when scaling and you may find horizontal scaling isn’t the right choice, after all.

For example, assume you have a tech news website where you did an early-look review of an upcoming—and highly-anticipated—smartphone launch, which went viral. The review, a blog post on your website, includes both video and pictures. Comments are enabled for the post and readers can also rate it. For example, if your website is hosted on a traditional Linux with a LAMP stack, you may find yourself with immediate scaling problems.

Let’s get more details on the current scenario and dig out more:

  • Where are images and videos stored?
  • How many read/write requests are received per second? Per minute?
  • What is the level of security required?
  • Are these synchronous or asynchronous requests?

We’ll also want to consider the following if your website has a transactional load like e-commerce or banking:

How is the website handling sessions?

  • Do you have any compliance requests—like the Payment Card Industry Data Security Standard (PCI DSS compliance) —if your website is using its own payment gateway?
  • How are you recording customer behavior data and fulfilling your analytics needs?
  • What are your loading balancing considerations (scaling, caching, session maintenance, etc.)?

So, if we take this one step at a time:

Step 1: Ease server load. We need to quickly handle spikes in traffic, generated by activity on the blog post, so let’s reduce server load by moving image and video to some third -party content delivery network (CDN). AWS provides Amazon CloudFront as a CDN solution, which is highly scalable with built-in security to verify origin access identity and handle any DDoS attacks. CloudFront can direct traffic to your on-premises or cloud-hosted server with its 113 Points of Presence (102 Edge Locations and 11 Regional Edge Caches) in 56 cities across 24 countries, which provides efficient caching.
Step 2: Reduce read load by adding more read replicas. MySQL provides a nice mirror replication for databases. Oracle has its own Oracle plug for replication and AWS RDS provide up to five read replicas, which can span across the region and even the Amazon database Amazon Aurora can have 15 read replicas with Amazon Aurora autoscaling support. If a workload is highly variable, you should consider Amazon Aurora Serverless database  to achieve high efficiency and reduced cost. While most mirror technologies do asynchronous replication, AWS RDS can provide synchronous multi-AZ replication, which is good for disaster recovery but not for scalability. Asynchronous replication to mirror instance means replication data can sometimes be stale if network bandwidth is low, so you need to plan and design your application accordingly.

I recommend that you always use a read replica for any reporting needs and try to move non-critical GET services to read replica and reduce the load on the master database. In this case, loading comments associated with a blog can be fetched from a read replica—as it can handle some delay—in case there is any issue with asynchronous reflection.

Step 3: Reduce write requests. This can be achieved by introducing queue to process the asynchronous message. Amazon Simple Queue Service (Amazon SQS) is a highly-scalable queue, which can handle any kind of work-message load. You can process data, like rating and review; or calculate Deal Quality Score (DQS) using batch processing via an SQS queue. If your workload is in AWS, I recommend using a job-observer pattern by setting up Auto Scaling to automatically increase or decrease the number of batch servers, using the number of SQS messages, with Amazon CloudWatch, as the trigger.  For on-premises workloads, you can use SQS SDK to create an Amazon SQS queue that holds messages until they’re processed by your stack. Or you can use Amazon SNS  to fan out your message processing in parallel for different purposes like adding a watermark in an image, generating a thumbnail, etc.

Step 4: Introduce a more robust caching engine. You can use Amazon Elastic Cache for Memcached or Redis to reduce write requests. Memcached and Redis have different use cases so if you can afford to lose and recover your cache from your database, use Memcached. If you are looking for more robust data persistence and complex data structure, use Redis. In AWS, these are managed services, which means AWS takes care of the workload for you and you can also deploy them in your on-premises instances or use a hybrid approach.

Step 5: Scale your server. If there are still issues, it’s time to scale your server.  For the greatest cost-effectiveness and unlimited scalability, I suggest always using horizontal scaling. However, use cases like database vertical scaling may be a better choice until you are good with sharding; or use Amazon Aurora Serverless for variable workloads. It will be wise to use Auto Scaling to manage your workload effectively for horizontal scaling. Also, to achieve that, you need to persist the session. Amazon DynamoDB can handle session persistence across instances.

If your server is on premises, consider creating a multisite architecture, which will help you achieve quick scalability as required and provide a good disaster recovery solution.  You can pick and choose individual services like Amazon Route 53, AWS CloudFormation, Amazon SQS, Amazon SNS, Amazon RDS, etc. depending on your needs.

Your multisite architecture will look like the following diagram:

In this architecture, you can run your regular workload on premises, and use your AWS workload as required for scalability and disaster recovery. Using Route 53, you can direct a precise percentage of users to an AWS workload.

If you decide to move all of your workloads to AWS, the recommended multi-AZ architecture would look like the following:

In this architecture, you are using a multi-AZ distributed workload for high availability. You can have a multi-region setup and use Route53 to distribute your workload between AWS Regions. CloudFront helps you to scale and distribute static content via an S3 bucket and DynamoDB, maintaining your application state so that Auto Scaling can apply horizontal scaling without loss of session data. At the database layer, RDS with multi-AZ standby provides high availability and read replica helps achieve scalability.

This is a high-level strategy to help you think through the scalability of your workload by using AWS even if your workload in on premises and not in the cloud…yet.

I highly recommend creating a hybrid, multisite model by placing your on-premises environment replica in the public cloud like AWS Cloud, and using Amazon Route53 DNS Service and Elastic Load Balancing to route traffic between on-premises and cloud environments. AWS now supports load balancing between AWS and on-premises environments to help you scale your cloud environment quickly, whenever required, and reduce it further by applying Amazon auto-scaling and placing a threshold on your on-premises traffic using Route 53.

Using Amazon CloudWatch and Amazon SNS to Notify when AWS X-Ray Detects Elevated Levels of Latency, Errors, and Faults in Your Application

Post Syndicated from Bharath Kumar original https://aws.amazon.com/blogs/devops/using-amazon-cloudwatch-and-amazon-sns-to-notify-when-aws-x-ray-detects-elevated-levels-of-latency-errors-and-faults-in-your-application/

AWS X-Ray helps developers analyze and debug production applications built using microservices or serverless architectures and quantify customer impact. With X-Ray, you can understand how your application and its underlying services are performing and identify and troubleshoot the root cause of performance issues and errors. You can use these insights to identify issues and opportunities for optimization.

In this blog post, I will show you how you can use Amazon CloudWatch and Amazon SNS to get notified when X-Ray detects high latency, errors, and faults in your application. Specifically, I will show you how to use this sample app to get notified through an email or SMS message when your end users observe high latencies or server-side errors when they use your application. You can customize the alarms and events by updating the sample app code.

Sample App Overview

The sample app uses the X-Ray GetServiceGraph API to get the following information:

  • Aggregated response time.
  • Requests that failed with 4xx status code (errors).
  • 429 status code (throttle).
  • 5xx status code (faults).
Sample app architecture

Overview of sample app architecture

Getting started

The sample app uses AWS CloudFormation to deploy the required resources.
To install the sample app:

  1. Run git clone to get the sample app.
  2. Update the JSON file in the Setup folder with threshold limits and notification details.
  3. Run the install.py script to install the sample app.

For more information about the installation steps, see the readme file on GitHub.

You can update the app configuration to include your phone number or email to get notified when your application in X-Ray breaches the latency, error, and fault limits you set in the configuration. If you prefer to not provide your phone number and email, then you can use the CloudWatch alarm deployed by the sample app to monitor your application in X-Ray.

The sample app deploys resources with the sample app namespace you provided during setup. This enables you to have multiple sample apps in the same region.

CloudWatch rules

The sample app uses two CloudWatch rules:

  1. SCHEDULEDLAMBDAFOR-sample_app_name to trigger at regular intervals the AWS Lambda function that queries the GetServiceGraph API.
  2. XRAYALERTSFOR-sample_app_name to look for published CloudWatch events that match the pattern defined in this rule.
CloudWatch Rules for sample app

CloudWatch rules created for the sample app

CloudWatch alarms

If you did not provide your phone number or email in the JSON file, the sample app uses a CloudWatch alarm named XRayCloudWatchAlarm-sample_app_name in combination with the CloudWatch event that you can use for monitoring.

CloudWatch Alarm for sample app

CloudWatch alarm created for the sample app

Amazon SNS messages

The sample app creates two SNS topics:

  • sample_app_name-cloudwatcheventsnstopic to send out an SMS message when the CloudWatch event matches a pattern published from the Lambda function.
  • sample_app_name-cloudwatchalarmsnstopic to send out an email message when the CloudWatch alarm goes into an ALARM state.
Amazon SNS for sample app

Amazon SNS created for the sample app

Getting notifications

The CloudWatch event looks for the following matching pattern:

{
  "detail-type": [
    "XCW Notification for Alerts"
  ],
  "source": [
    "<sample_app_name>-xcw.alerts"
  ]
}

The event then invokes an SNS topic that sends out an SMS message.

SMS in sample app

SMS that is sent when CloudWatch Event invokes Amazon SNS topic

The CloudWatch alarm looks for the TriggeredRules metric that is published whenever the CloudWatch event matches the event pattern. It goes into the ALARM state whenever TriggeredRules > 0 for the specified evaluation period and invokes an SNS topic that sends an email message.

Email sent in sample app

Email that is sent when CloudWatch Alarm goes to ALARM state

Stopping notifications

If you provided your phone number or email address, but would like to stop getting notified, change the SUBSCRIBE_TO_EMAIL_SMS environment variable in the Lambda function to No. Then, go to the Amazon SNS console and delete the subscriptions. You can still monitor your application for elevated levels of latency, errors, and faults by using the CloudWatch console.

Lambda environment variable in sample app

Change environment variable in Lambda

 

Delete subscription in SNS for sample app

Delete subscriptions to stop getting notified

Uninstalling the sample app

To uninstall the sample app, run the uninstall.py script in the Setup folder.

Extending the sample app

The sample app notifes you when when X-Ray detects high latency, errors, and faults in your application. You can extend it to provide more value for your use cases (for example, to perform an action on a resource when the state of a CloudWatch alarm changes).

To summarize, after this set up you will be able to get notified through Amazon SNS when X-Ray detects high latency, errors and faults in your application.

I hope you found this information about setting up alarms and alerts for your application in AWS X-Ray helpful. Feel free to leave questions or other feedback in the comments. Feel free to learn more about AWS X-Ray, Amazon SNS and Amazon CloudWatch

About the Author

Bharath Kumar is a Sr.Product Manager with AWS X-Ray. He has developed and launched mobile games, web applications on microservices and serverless architecture.

Serverless Automated Cost Controls, Part1

Post Syndicated from Shankar Ramachandran original https://aws.amazon.com/blogs/compute/serverless-automated-cost-controls-part1/

This post courtesy of Shankar Ramachandran, Pubali Sen, and George Mao

In line with AWS’s continual efforts to reduce costs for customers, this series focuses on how customers can build serverless automated cost controls. This post provides an architecture blueprint and a sample implementation to prevent budget overruns.

This solution uses the following AWS products:

  • AWS Budgets – An AWS Cost Management tool that helps customers define and track budgets for AWS costs, and forecast for up to three months.
  • Amazon SNS – An AWS service that makes it easy to set up, operate, and send notifications from the cloud.
  • AWS Lambda – An AWS service that lets you run code without provisioning or managing servers.

You can fine-tune a budget for various parameters, for example filtering by service or tag. The Budgets tool lets you post notifications on an SNS topic. A Lambda function that subscribes to the SNS topic can act on the notification. Any programmatically implementable action can be taken.

The diagram below describes the architecture blueprint.

In this post, we describe how to use this blueprint with AWS Step Functions and IAM to effectively revoke the ability of a user to start new Amazon EC2 instances, after a budget amount is exceeded.

Freedom with guardrails

AWS lets you quickly spin up resources as you need them, deploying hundreds or even thousands of servers in minutes. This means you can quickly develop and roll out new applications. Teams can experiment and innovate more quickly and frequently. If an experiment fails, you can always de-provision those servers without risk.

This improved agility also brings in the need for effective cost controls. Your Finance and Accounting department must budget, monitor, and control the AWS spend. For example, this could be a budget per project. Further, Finance and Accounting must take appropriate actions if the budget for the project has been exceeded, for example. Call it “freedom with guardrails” – where Finance wants to give developers freedom, but with financial constraints.

Architecture

This section describes how to use the blueprint introduced earlier to implement a “freedom with guardrails” solution.

  1. The budget for “Project Beta” is set up in Budgets. In this example, we focus on EC2 usage and identify the instances that belong to this project by filtering on the tag Project with the value Beta. For more information, see Creating a Budget.
  2. The budget configuration also includes settings to send a notification on an SNS topic when the usage exceeds 100% of the budgeted amount. For more information, see Creating an Amazon SNS Topic for Budget Notifications.
  3. The master Lambda function receives the SNS notification.
  4. It triggers execution of a Step Functions state machine with the parameters for completing the configured action.
  5. The action Lambda function is triggered as a task in the state machine. The function interacts with IAM to effectively remove the user’s permissions to create an EC2 instance.

This decoupled modular design allows for extensibility.  New actions (serially or in parallel) can be added by simply adding new steps.

Implementing the solution

All the instructions and code needed to implement the architecture have been posted on the Serverless Automated Cost Controls GitHub repo. We recommend that you try this first in a Dev/Test environment.

This implementation description can be broken down into two parts:

  1. Create a solution stack for serverless automated cost controls.
  2. Verify the solution by testing the EC2 fleet.

To tie this back to the “freedom with guardrails” scenario, the Finance department performs a one-time implementation of the solution stack. To simulate resources for Project Beta, the developers spin up the test EC2 fleet.

Prerequisites

There are two prerequisites:

  • Make sure that you have the necessary IAM permissions. For more information, see the section titled “Required IAM permissions” in the README.
  • Define and activate a cost allocation tag with the key Project. For more information, see Using Cost Allocation Tags. It can take up to 12 hours for the tags to propagate to Budgets.

Create resources

The solution stack includes creating the following resources:

  • Three Lambda functions
  • One Step Functions state machine
  • One SNS topic
  • One IAM group
  • One IAM user
  • IAM policies as needed
  • One budget

Two of the Lambda functions were described in the previous section, to a) receive the SNS notification and b) trigger the Step Functions state machine. Another Lambda function is used to create the budget, as a custom AWS CloudFormation resource. The SNS topic connects Budgets with Lambda function A. Lambda function B is configured as a task in Step Functions. A budget for $2 is created which is filtered by Service: EC2 and Tag: Project, Beta. A test IAM group and user is created to enable you to validate this Cost Control Solution.

To create the serverless automated cost control solution stack, choose the button below. It takes few minutes to spin up the stack. You can monitor the progress in the CloudFormation console.

When you see the CREATE_COMPLETE status for the stack you had created, choose Outputs. Copy the following four values that you need later:

  • TemplateURL
  • UserName
  • SignInURL
  • Password

Verify the stack

The next step is to verify the serverless automated cost controls solution stack that you just created. To do this, spin up an EC2 fleet of t2.micro instances, representative of the resources needed for Project Beta, and tag them with Project, Beta.

  1. Browse to the SignInURL, and log in using the UserName and Password values copied on from the stack output.
  2. In the CloudFormation console, choose Create Stack.
  3. For Choose a template, select Choose an Amazon S3 template URL and paste the TemplateURL value from the preceding section. Choose Next.
  4. Give this stack a name, such as “testEc2FleetForProjectBeta”. Choose Next.
  5. On the Specify Details page, enter parameters such as the UserName and Password copied in the previous section. Choose Next.
  6. Ignore any errors related to listing IAM roles. The test user has a minimal set of permissions that is just sufficient to spin up this test stack (in line with security best practices).
  7. On the Options page, choose Next.
  8. On the Review page, choose Create. It takes a few minutes to spin up the stack, and you can monitor the progress in the CloudFormation console. 
  9. When you see the status “CREATE_COMPLETE”, open the EC2 console to verify that four t2.micro instances have been spun up, with the tag of Project, Beta.

The hourly cost for these instances depends on the region in which they are running. On the average (irrespective of the region), you can expect the aggregate cost for this EC2 fleet to exceed the set $2 budget in 48 hours.

Verify the solution

The first step is to identify the test IAM group that was created in the previous section. The group should have “projectBeta” in the name, prepended with the CloudFormation stack name and appended with an alphanumeric string. Verify that the managed policy associated is: “EC2FullAccess”, which indicates that the users in this group have unrestricted access to EC2.

There are two stages of verification for this serverless automated cost controls solution: simulating a notification and waiting for a breach.

Simulated notification

Because it takes at least a few hours for the aggregate cost of the EC2 fleet to breach the set budget, you can verify the solution by simulating the notification from Budgets.

  1. Log in to the SNS console (using your regular AWS credentials).
  2. Publish a message on the SNS topic that has “budgetNotificationTopic” in the name. The complete name is appended by the CloudFormation stack identifier.  
  3. Copy the following text as the body of the notification: “This is a mock notification”.
  4. Choose Publish.
  5. Open the IAM console to verify that the policy for the test group has been switched to “EC2ReadOnly”. This prevents users in this group from creating new instances.
  6. Verify that the test user created in the previous section cannot spin up new EC2 instances.  You can log in as the test user and try creating a new EC2 instance (via the same CloudFormation stack or the EC2 console). You should get an error message indicating that you do not have the necessary permissions.
  7. If you are proceeding to stage 2 of the verification, then you must switch the permissions back to “EC2FullAccess” for the test group, which can be done in the IAM console.

Automatic notification

Within 48 hours, the aggregate cost of the EC2 fleet spun up in the earlier section breaches the budget rule and triggers an automatic notification. This results in the permissions getting switched out, just as in the simulated notification.

Clean up

Use the following steps to delete your resources and stop incurring costs.

  1. Open the CloudFormation console.
  2. Delete the EC2 fleet by deleting the appropriate stack (for example, delete the stack named “testEc2FleetForProjectBeta”).                                               
  3. Next, delete the “costControlStack” stack.                                                                                                                                                    

Conclusion

Using Lambda in tandem with Budgets, you can build Serverless automated cost controls on AWS. Find all the resources (instructions, code) for implementing the solution discussed in this post on the Serverless Automated Cost Controls GitHub repo.

Stay tuned to this series for more tips about building serverless automated cost controls. In the next post, we discuss using smart lighting to influence developer behavior and describe a solution to encourage cost-aware development practices.

If you have questions or suggestions, please comment below.

 

How to Patch, Inspect, and Protect Microsoft Windows Workloads on AWS—Part 2

Post Syndicated from Koen van Blijderveen original https://aws.amazon.com/blogs/security/how-to-patch-inspect-and-protect-microsoft-windows-workloads-on-aws-part-2/

Yesterday in Part 1 of this blog post, I showed you how to:

  1. Launch an Amazon EC2 instance with an AWS Identity and Access Management (IAM) role, an Amazon Elastic Block Store (Amazon EBS) volume, and tags that Amazon EC2 Systems Manager (Systems Manager) and Amazon Inspector use.
  2. Configure Systems Manager to install the Amazon Inspector agent and patch your EC2 instances.

Today in Steps 3 and 4, I show you how to:

  1. Take Amazon EBS snapshots using Amazon EBS Snapshot Scheduler to automate snapshots based on instance tags.
  2. Use Amazon Inspector to check if your EC2 instances running Microsoft Windows contain any common vulnerabilities and exposures (CVEs).

To catch up on Steps 1 and 2, see yesterday’s blog post.

Step 3: Take EBS snapshots using EBS Snapshot Scheduler

In this section, I show you how to use EBS Snapshot Scheduler to take snapshots of your instances at specific intervals. To do this, I will show you how to:

  • Determine the schedule for EBS Snapshot Scheduler by providing you with best practices.
  • Deploy EBS Snapshot Scheduler by using AWS CloudFormation.
  • Tag your EC2 instances so that EBS Snapshot Scheduler backs up your instances when you want them backed up.

In addition to making sure your EC2 instances have all the available operating system patches applied on a regular schedule, you should take snapshots of the EBS storage volumes attached to your EC2 instances. Taking regular snapshots allows you to restore your data to a previous state quickly and cost effectively. With Amazon EBS snapshots, you pay only for the actual data you store, and snapshots save only the data that has changed since the previous snapshot, which minimizes your cost. You will use EBS Snapshot Scheduler to make regular snapshots of your EC2 instance. EBS Snapshot Scheduler takes advantage of other AWS services including CloudFormation, Amazon DynamoDB, and AWS Lambda to make backing up your EBS volumes simple.

Determine the schedule

As a best practice, you should back up your data frequently during the hours when your data changes the most. This reduces the amount of data you lose if you have to restore from a snapshot. For the purposes of this blog post, the data for my instances changes the most between the business hours of 9:00 A.M. to 5:00 P.M. Pacific Time. During these hours, I will make snapshots hourly to minimize data loss.

In addition to backing up frequently, another best practice is to establish a strategy for retention. This will vary based on how you need to use the snapshots. If you have compliance requirements to be able to restore for auditing, your needs may be different than if you are able to detect data corruption within three hours and simply need to restore to something that limits data loss to five hours. EBS Snapshot Scheduler enables you to specify the retention period for your snapshots. For this post, I only need to keep snapshots for recent business days. To account for weekends, I will set my retention period to three days, which is down from the default of 15 days when deploying EBS Snapshot Scheduler.

Deploy EBS Snapshot Scheduler

In Step 1 of Part 1 of this post, I showed how to configure an EC2 for Windows Server 2012 R2 instance with an EBS volume. You will use EBS Snapshot Scheduler to take eight snapshots each weekday of your EC2 instance’s EBS volumes:

  1. Navigate to the EBS Snapshot Scheduler deployment page and choose Launch Solution. This takes you to the CloudFormation console in your account. The Specify an Amazon S3 template URL option is already selected and prefilled. Choose Next on the Select Template page.
  2. On the Specify Details page, retain all default parameters except for AutoSnapshotDeletion. Set AutoSnapshotDeletion to Yes to ensure that old snapshots are periodically deleted. The default retention period is 15 days (you will specify a shorter value on your instance in the next subsection).
  3. Choose Next twice to move to the Review step, and start deployment by choosing the I acknowledge that AWS CloudFormation might create IAM resources check box and then choosing Create.

Tag your EC2 instances

EBS Snapshot Scheduler takes a few minutes to deploy. While waiting for its deployment, you can start to tag your instance to define its schedule. EBS Snapshot Scheduler reads tag values and looks for four possible custom parameters in the following order:

  • <snapshot time> – Time in 24-hour format with no colon.
  • <retention days> – The number of days (a positive integer) to retain the snapshot before deletion, if set to automatically delete snapshots.
  • <time zone> – The time zone of the times specified in <snapshot time>.
  • <active day(s)>all, weekdays, or mon, tue, wed, thu, fri, sat, and/or sun.

Because you want hourly backups on weekdays between 9:00 A.M. and 5:00 P.M. Pacific Time, you need to configure eight tags—one for each hour of the day. You will add the eight tags shown in the following table to your EC2 instance.

Tag Value
scheduler:ebs-snapshot:0900 0900;3;utc;weekdays
scheduler:ebs-snapshot:1000 1000;3;utc;weekdays
scheduler:ebs-snapshot:1100 1100;3;utc;weekdays
scheduler:ebs-snapshot:1200 1200;3;utc;weekdays
scheduler:ebs-snapshot:1300 1300;3;utc;weekdays
scheduler:ebs-snapshot:1400 1400;3;utc;weekdays
scheduler:ebs-snapshot:1500 1500;3;utc;weekdays
scheduler:ebs-snapshot:1600 1600;3;utc;weekdays

Next, you will add these tags to your instance. If you want to tag multiple instances at once, you can use Tag Editor instead. To add the tags in the preceding table to your EC2 instance:

  1. Navigate to your EC2 instance in the EC2 console and choose Tags in the navigation pane.
  2. Choose Add/Edit Tags and then choose Create Tag to add all the tags specified in the preceding table.
  3. Confirm you have added the tags by choosing Save. After adding these tags, navigate to your EC2 instance in the EC2 console. Your EC2 instance should look similar to the following screenshot.
    Screenshot of how your EC2 instance should look in the console
  4. After waiting a couple of hours, you can see snapshots beginning to populate on the Snapshots page of the EC2 console.Screenshot of snapshots beginning to populate on the Snapshots page of the EC2 console
  5. To check if EBS Snapshot Scheduler is active, you can check the CloudWatch rule that runs the Lambda function. If the clock icon shown in the following screenshot is green, the scheduler is active. If the clock icon is gray, the rule is disabled and does not run. You can enable or disable the rule by selecting it, choosing Actions, and choosing Enable or Disable. This also allows you to temporarily disable EBS Snapshot Scheduler.Screenshot of checking to see if EBS Snapshot Scheduler is active
  1. You can also monitor when EBS Snapshot Scheduler has run by choosing the name of the CloudWatch rule as shown in the previous screenshot and choosing Show metrics for the rule.Screenshot of monitoring when EBS Snapshot Scheduler has run by choosing the name of the CloudWatch rule

If you want to restore and attach an EBS volume, see Restoring an Amazon EBS Volume from a Snapshot and Attaching an Amazon EBS Volume to an Instance.

Step 4: Use Amazon Inspector

In this section, I show you how to you use Amazon Inspector to scan your EC2 instance for common vulnerabilities and exposures (CVEs) and set up Amazon SNS notifications. To do this I will show you how to:

  • Install the Amazon Inspector agent by using EC2 Run Command.
  • Set up notifications using Amazon SNS to notify you of any findings.
  • Define an Amazon Inspector target and template to define what assessment to perform on your EC2 instance.
  • Schedule Amazon Inspector assessment runs to assess your EC2 instance on a regular interval.

Amazon Inspector can help you scan your EC2 instance using prebuilt rules packages, which are built and maintained by AWS. These prebuilt rules packages tell Amazon Inspector what to scan for on the EC2 instances you select. Amazon Inspector provides the following prebuilt packages for Microsoft Windows Server 2012 R2:

  • Common Vulnerabilities and Exposures
  • Center for Internet Security Benchmarks
  • Runtime Behavior Analysis

In this post, I’m focused on how to make sure you keep your EC2 instances patched, backed up, and inspected for common vulnerabilities and exposures (CVEs). As a result, I will focus on how to use the CVE rules package and use your instance tags to identify the instances on which to run the CVE rules. If your EC2 instance is fully patched using Systems Manager, as described earlier, you should not have any findings with the CVE rules package. Regardless, as a best practice I recommend that you use Amazon Inspector as an additional layer for identifying any unexpected failures. This involves using Amazon CloudWatch to set up weekly Amazon Inspector scans, and configuring Amazon Inspector to notify you of any findings through SNS topics. By acting on the notifications you receive, you can respond quickly to any CVEs on any of your EC2 instances to help ensure that malware using known CVEs does not affect your EC2 instances. In a previous blog post, Eric Fitzgerald showed how to remediate Amazon Inspector security findings automatically.

Install the Amazon Inspector agent

To install the Amazon Inspector agent, you will use EC2 Run Command, which allows you to run any command on any of your EC2 instances that have the Systems Manager agent with an attached IAM role that allows access to Systems Manager.

  1. Choose Run Command under Systems Manager Services in the navigation pane of the EC2 console. Then choose Run a command.
    Screenshot of choosing "Run a command"
  2. To install the Amazon Inspector agent, you will use an AWS managed and provided command document that downloads and installs the agent for you on the selected EC2 instance. Choose AmazonInspector-ManageAWSAgent. To choose the target EC2 instance where this command will be run, use the tag you previously assigned to your EC2 instance, Patch Group, with a value of Windows Servers. For this example, set the concurrent installations to 1 and tell Systems Manager to stop after 5 errors.
    Screenshot of installing the Amazon Inspector agent
  3. Retain the default values for all other settings on the Run a command page and choose Run. Back on the Run Command page, you can see if the command that installed the Amazon Inspector agent executed successfully on all selected EC2 instances.
    Screenshot showing that the command that installed the Amazon Inspector agent executed successfully on all selected EC2 instances

Set up notifications using Amazon SNS

Now that you have installed the Amazon Inspector agent, you will set up an SNS topic that will notify you of any findings after an Amazon Inspector run.

To set up an SNS topic:

  1. In the AWS Management Console, choose Simple Notification Service under Messaging in the Services menu.
  2. Choose Create topic, name your topic (only alphanumeric characters, hyphens, and underscores are allowed) and give it a display name to ensure you know what this topic does (I’ve named mine Inspector). Choose Create topic.
    "Create new topic" page
  3. To allow Amazon Inspector to publish messages to your new topic, choose Other topic actions and choose Edit topic policy.
  4. For Allow these users to publish messages to this topic and Allow these users to subscribe to this topic, choose Only these AWS users. Type the following ARN for the US East (N. Virginia) Region in which you are deploying the solution in this post: arn:aws:iam::316112463485:root. This is the ARN of Amazon Inspector itself. For the ARNs of Amazon Inspector in other AWS Regions, see Setting Up an SNS Topic for Amazon Inspector Notifications (Console). Amazon Resource Names (ARNs) uniquely identify AWS resources across all of AWS.
    Screenshot of editing the topic policy
  5. To receive notifications from Amazon Inspector, subscribe to your new topic by choosing Create subscription and adding your email address. After confirming your subscription by clicking the link in the email, the topic should display your email address as a subscriber. Later, you will configure the Amazon Inspector template to publish to this topic.
    Screenshot of subscribing to the new topic

Define an Amazon Inspector target and template

Now that you have set up the notification topic by which Amazon Inspector can notify you of findings, you can create an Amazon Inspector target and template. A target defines which EC2 instances are in scope for Amazon Inspector. A template defines which packages to run, for how long, and on which target.

To create an Amazon Inspector target:

  1. Navigate to the Amazon Inspector console and choose Get started. At the time of writing this blog post, Amazon Inspector is available in the US East (N. Virginia), US West (N. California), US West (Oregon), EU (Ireland), Asia Pacific (Mumbai), Asia Pacific (Seoul), Asia Pacific (Sydney), and Asia Pacific (Tokyo) Regions.
  2. For Amazon Inspector to be able to collect the necessary data from your EC2 instance, you must create an IAM service role for Amazon Inspector. Amazon Inspector can create this role for you if you choose Choose or create role and confirm the role creation by choosing Allow.
    Screenshot of creating an IAM service role for Amazon Inspector
  3. Amazon Inspector also asks you to tag your EC2 instance and install the Amazon Inspector agent. You already performed these steps in Part 1 of this post, so you can proceed by choosing Next. To define the Amazon Inspector target, choose the previously used Patch Group tag with a Value of Windows Servers. This is the same tag that you used to define the targets for patching. Then choose Next.
    Screenshot of defining the Amazon Inspector target
  4. Now, define your Amazon Inspector template, and choose a name and the package you want to run. For this post, use the Common Vulnerabilities and Exposures package and choose the default duration of 1 hour. As you can see, the package has a version number, so always select the latest version of the rules package if multiple versions are available.
    Screenshot of defining an assessment template
  5. Configure Amazon Inspector to publish to your SNS topic when findings are reported. You can also choose to receive a notification of a started run, a finished run, or changes in the state of a run. For this blog post, you want to receive notifications if there are any findings. To start, choose Assessment Templates from the Amazon Inspector console and choose your newly created Amazon Inspector assessment template. Choose the icon below SNS topics (see the following screenshot).
    Screenshot of choosing an assessment template
  6. A pop-up appears in which you can choose the previously created topic and the events about which you want SNS to notify you (choose Finding reported).
    Screenshot of choosing the previously created topic and the events about which you want SNS to notify you

Schedule Amazon Inspector assessment runs

The last step in using Amazon Inspector to assess for CVEs is to schedule the Amazon Inspector template to run using Amazon CloudWatch Events. This will make sure that Amazon Inspector assesses your EC2 instance on a regular basis. To do this, you need the Amazon Inspector template ARN, which you can find under Assessment templates in the Amazon Inspector console. CloudWatch Events can run your Amazon Inspector assessment at an interval you define using a Cron-based schedule. Cron is a well-known scheduling agent that is widely used on UNIX-like operating systems and uses the following syntax for CloudWatch Events.

Image of Cron schedule

All scheduled events use a UTC time zone, and the minimum precision for schedules is one minute. For more information about scheduling CloudWatch Events, see Schedule Expressions for Rules.

To create the CloudWatch Events rule:

  1. Navigate to the CloudWatch console, choose Events, and choose Create rule.
    Screenshot of starting to create a rule in the CloudWatch Events console
  2. On the next page, specify if you want to invoke your rule based on an event pattern or a schedule. For this blog post, you will select a schedule based on a Cron expression.
  3. You can schedule the Amazon Inspector assessment any time you want using the Cron expression, or you can use the Cron expression I used in the following screenshot, which will run the Amazon Inspector assessment every Sunday at 10:00 P.M. GMT.
    Screenshot of scheduling an Amazon Inspector assessment with a Cron expression
  4. Choose Add target and choose Inspector assessment template from the drop-down menu. Paste the ARN of the Amazon Inspector template you previously created in the Amazon Inspector console in the Assessment template box and choose Create a new role for this specific resource. This new role is necessary so that CloudWatch Events has the necessary permissions to start the Amazon Inspector assessment. CloudWatch Events will automatically create the new role and grant the minimum set of permissions needed to run the Amazon Inspector assessment. To proceed, choose Configure details.
    Screenshot of adding a target
  5. Next, give your rule a name and a description. I suggest using a name that describes what the rule does, as shown in the following screenshot.
  6. Finish the wizard by choosing Create rule. The rule should appear in the Events – Rules section of the CloudWatch console.
    Screenshot of completing the creation of the rule
  7. To confirm your CloudWatch Events rule works, wait for the next time your CloudWatch Events rule is scheduled to run. For testing purposes, you can choose your CloudWatch Events rule and choose Edit to change the schedule to run it sooner than scheduled.
    Screenshot of confirming the CloudWatch Events rule works
  8. Now navigate to the Amazon Inspector console to confirm the launch of your first assessment run. The Start time column shows you the time each assessment started and the Status column the status of your assessment. In the following screenshot, you can see Amazon Inspector is busy Collecting data from the selected assessment targets.
    Screenshot of confirming the launch of the first assessment run

You have concluded the last step of this blog post by setting up a regular scan of your EC2 instance with Amazon Inspector and a notification that will let you know if your EC2 instance is vulnerable to any known CVEs. In a previous Security Blog post, Eric Fitzgerald explained How to Remediate Amazon Inspector Security Findings Automatically. Although that blog post is for Linux-based EC2 instances, the post shows that you can learn about Amazon Inspector findings in other ways than email alerts.

Conclusion

In this two-part blog post, I showed how to make sure you keep your EC2 instances up to date with patching, how to back up your instances with snapshots, and how to monitor your instances for CVEs. Collectively these measures help to protect your instances against common attack vectors that attempt to exploit known vulnerabilities. In Part 1, I showed how to configure your EC2 instances to make it easy to use Systems Manager, EBS Snapshot Scheduler, and Amazon Inspector. I also showed how to use Systems Manager to schedule automatic patches to keep your instances current in a timely fashion. In Part 2, I showed you how to take regular snapshots of your data by using EBS Snapshot Scheduler and how to use Amazon Inspector to check if your EC2 instances running Microsoft Windows contain any common vulnerabilities and exposures (CVEs).

If you have comments about today’s or yesterday’s post, submit them in the “Comments” section below. If you have questions about or issues implementing any part of this solution, start a new thread on the Amazon EC2 forum or the Amazon Inspector forum, or contact AWS Support.

– Koen

Event-Driven Computing with Amazon SNS and AWS Compute, Storage, Database, and Networking Services

Post Syndicated from Christie Gifrin original https://aws.amazon.com/blogs/compute/event-driven-computing-with-amazon-sns-compute-storage-database-and-networking-services/

Contributed by Otavio Ferreira, Manager, Software Development, AWS Messaging

Like other developers around the world, you may be tackling increasingly complex business problems. A key success factor, in that case, is the ability to break down a large project scope into smaller, more manageable components. A service-oriented architecture guides you toward designing systems as a collection of loosely coupled, independently scaled, and highly reusable services. Microservices take this even further. To improve performance and scalability, they promote fine-grained interfaces and lightweight protocols.

However, the communication among isolated microservices can be challenging. Services are often deployed onto independent servers and don’t share any compute or storage resources. Also, you should avoid hard dependencies among microservices, to preserve maintainability and reusability.

If you apply the pub/sub design pattern, you can effortlessly decouple and independently scale out your microservices and serverless architectures. A pub/sub messaging service, such as Amazon SNS, promotes event-driven computing that statically decouples event publishers from subscribers, while dynamically allowing for the exchange of messages between them. An event-driven architecture also introduces the responsiveness needed to deal with complex problems, which are often unpredictable and asynchronous.

What is event-driven computing?

Given the context of microservices, event-driven computing is a model in which subscriber services automatically perform work in response to events triggered by publisher services. This paradigm can be applied to automate workflows while decoupling the services that collectively and independently work to fulfil these workflows. Amazon SNS is an event-driven computing hub, in the AWS Cloud, that has native integration with several AWS publisher and subscriber services.

Which AWS services publish events to SNS natively?

Several AWS services have been integrated as SNS publishers and, therefore, can natively trigger event-driven computing for a variety of use cases. In this post, I specifically cover AWS compute, storage, database, and networking services, as depicted below.

Compute services

  • Auto Scaling: Helps you ensure that you have the correct number of Amazon EC2 instances available to handle the load for your application. You can configure Auto Scaling lifecycle hooks to trigger events, as Auto Scaling resizes your EC2 cluster.As an example, you may want to warm up the local cache store on newly launched EC2 instances, and also download log files from other EC2 instances that are about to be terminated. To make this happen, set an SNS topic as your Auto Scaling group’s notification target, then subscribe two Lambda functions to this SNS topic. The first function is responsible for handling scale-out events (to warm up cache upon provisioning), whereas the second is in charge of handling scale-in events (to download logs upon termination).

  • AWS Elastic Beanstalk: An easy-to-use service for deploying and scaling web applications and web services developed in a number of programming languages. You can configure event notifications for your Elastic Beanstalk environment so that notable events can be automatically published to an SNS topic, then pushed to topic subscribers.As an example, you may use this event-driven architecture to coordinate your continuous integration pipeline (such as Jenkins CI). That way, whenever an environment is created, Elastic Beanstalk publishes this event to an SNS topic, which triggers a subscribing Lambda function, which then kicks off a CI job against your newly created Elastic Beanstalk environment.

  • Elastic Load Balancing: Automatically distributes incoming application traffic across Amazon EC2 instances, containers, or other resources identified by IP addresses.You can configure CloudWatch alarms on Elastic Load Balancing metrics, to automate the handling of events derived from Classic Load Balancers. As an example, you may leverage this event-driven design to automate latency profiling in an Amazon ECS cluster behind a Classic Load Balancer. In this example, whenever your ECS cluster breaches your load balancer latency threshold, an event is posted by CloudWatch to an SNS topic, which then triggers a subscribing Lambda function. This function runs a task on your ECS cluster to trigger a latency profiling tool, hosted on the cluster itself. This can enhance your latency troubleshooting exercise by making it timely.

Storage services

  • Amazon S3: Object storage built to store and retrieve any amount of data.You can enable S3 event notifications, and automatically get them posted to SNS topics, to automate a variety of workflows. For instance, imagine that you have an S3 bucket to store incoming resumes from candidates, and a fleet of EC2 instances to encode these resumes from their original format (such as Word or text) into a portable format (such as PDF).In this example, whenever new files are uploaded to your input bucket, S3 publishes these events to an SNS topic, which in turn pushes these messages into subscribing SQS queues. Then, encoding workers running on EC2 instances poll these messages from the SQS queues; retrieve the original files from the input S3 bucket; encode them into PDF; and finally store them in an output S3 bucket.

  • Amazon EFS: Provides simple and scalable file storage, for use with Amazon EC2 instances, in the AWS Cloud.You can configure CloudWatch alarms on EFS metrics, to automate the management of your EFS systems. For example, consider a highly parallelized genomics analysis application that runs against an EFS system. By default, this file system is instantiated on the “General Purpose” performance mode. Although this performance mode allows for lower latency, it might eventually impose a scaling bottleneck. Therefore, you may leverage an event-driven design to handle it automatically.Basically, as soon as the EFS metric “Percent I/O Limit” breaches 95%, CloudWatch could post this event to an SNS topic, which in turn would push this message into a subscribing Lambda function. This function automatically creates a new file system, this time on the “Max I/O” performance mode, then switches the genomics analysis application to this new file system. As a result, your application starts experiencing higher I/O throughput rates.

  • Amazon Glacier: A secure, durable, and low-cost cloud storage service for data archiving and long-term backup.You can set a notification configuration on an Amazon Glacier vault so that when a job completes, a message is published to an SNS topic. Retrieving an archive from Amazon Glacier is a two-step asynchronous operation, in which you first initiate a job, and then download the output after the job completes. Therefore, SNS helps you eliminate polling your Amazon Glacier vault to check whether your job has been completed, or not. As usual, you may subscribe SQS queues, Lambda functions, and HTTP endpoints to your SNS topic, to be notified when your Amazon Glacier job is done.

  • AWS Snowball: A petabyte-scale data transport solution that uses secure appliances to transfer large amounts of data.You can leverage Snowball notifications to automate workflows related to importing data into and exporting data from AWS. More specifically, whenever your Snowball job status changes, Snowball can publish this event to an SNS topic, which in turn can broadcast the event to all its subscribers.As an example, imagine a Geographic Information System (GIS) that distributes high-resolution satellite images to users via Web browser. In this example, the GIS vendor could capture up to 80 TB of satellite images; create a Snowball job to import these files from an on-premises system to an S3 bucket; and provide an SNS topic ARN to be notified upon job status changes in Snowball. After Snowball changes the job status from “Importing” to “Completed”, Snowball publishes this event to the specified SNS topic, which delivers this message to a subscribing Lambda function, which finally creates a CloudFront web distribution for the target S3 bucket, to serve the images to end users.

Database services

  • Amazon RDS: Makes it easy to set up, operate, and scale a relational database in the cloud.RDS leverages SNS to broadcast notifications when RDS events occur. As usual, these notifications can be delivered via any protocol supported by SNS, including SQS queues, Lambda functions, and HTTP endpoints.As an example, imagine that you own a social network website that has experienced organic growth, and needs to scale its compute and database resources on demand. In this case, you could provide an SNS topic to listen to RDS DB instance events. When the “Low Storage” event is published to the topic, SNS pushes this event to a subscribing Lambda function, which in turn leverages the RDS API to increase the storage capacity allocated to your DB instance. The provisioning itself takes place within the specified DB maintenance window.

  • Amazon ElastiCache: A web service that makes it easy to deploy, operate, and scale an in-memory data store or cache in the cloud.ElastiCache can publish messages using Amazon SNS when significant events happen on your cache cluster. This feature can be used to refresh the list of servers on client machines connected to individual cache node endpoints of a cache cluster. For instance, an ecommerce website fetches product details from a cache cluster, with the goal of offloading a relational database and speeding up page load times. Ideally, you want to make sure that each web server always has an updated list of cache servers to which to connect.To automate this node discovery process, you can get your ElastiCache cluster to publish events to an SNS topic. Thus, when ElastiCache event “AddCacheNodeComplete” is published, your topic then pushes this event to all subscribing HTTP endpoints that serve your ecommerce website, so that these HTTP servers can update their list of cache nodes.

  • Amazon Redshift: A fully managed data warehouse that makes it simple to analyze data using standard SQL and BI (Business Intelligence) tools.Amazon Redshift uses SNS to broadcast relevant events so that data warehouse workflows can be automated. As an example, imagine a news website that sends clickstream data to a Kinesis Firehose stream, which then loads the data into Amazon Redshift, so that popular news and reading preferences might be surfaced on a BI tool. At some point though, this Amazon Redshift cluster might need to be resized, and the cluster enters a ready-only mode. Hence, this Amazon Redshift event is published to an SNS topic, which delivers this event to a subscribing Lambda function, which finally deletes the corresponding Kinesis Firehose delivery stream, so that clickstream data uploads can be put on hold.At a later point, after Amazon Redshift publishes the event that the maintenance window has been closed, SNS notifies a subscribing Lambda function accordingly, so that this function can re-create the Kinesis Firehose delivery stream, and resume clickstream data uploads to Amazon Redshift.

  • AWS DMS: Helps you migrate databases to AWS quickly and securely. The source database remains fully operational during the migration, minimizing downtime to applications that rely on the database.DMS also uses SNS to provide notifications when DMS events occur, which can automate database migration workflows. As an example, you might create data replication tasks to migrate an on-premises MS SQL database, composed of multiple tables, to MySQL. Thus, if replication tasks fail due to incompatible data encoding in the source tables, these events can be published to an SNS topic, which can push these messages into a subscribing SQS queue. Then, encoders running on EC2 can poll these messages from the SQS queue, encode the source tables into a compatible character set, and restart the corresponding replication tasks in DMS. This is an event-driven approach to a self-healing database migration process.

Networking services

  • Amazon Route 53: A highly available and scalable cloud-based DNS (Domain Name System). Route 53 health checks monitor the health and performance of your web applications, web servers, and other resources.You can set CloudWatch alarms and get automated Amazon SNS notifications when the status of your Route 53 health check changes. As an example, imagine an online payment gateway that reports the health of its platform to merchants worldwide, via a status page. This page is hosted on EC2 and fetches platform health data from DynamoDB. In this case, you could configure a CloudWatch alarm for your Route 53 health check, so that when the alarm threshold is breached, and the payment gateway is no longer considered healthy, then CloudWatch publishes this event to an SNS topic, which pushes this message to a subscribing Lambda function, which finally updates the DynamoDB table that populates the status page. This event-driven approach avoids any kind of manual update to the status page visited by merchants.

  • AWS Direct Connect (AWS DX): Makes it easy to establish a dedicated network connection from your premises to AWS, which can reduce your network costs, increase bandwidth throughput, and provide a more consistent network experience than Internet-based connections.You can monitor physical DX connections using CloudWatch alarms, and send SNS messages when alarms change their status. As an example, when a DX connection state shifts to 0 (zero), indicating that the connection is down, this event can be published to an SNS topic, which can fan out this message to impacted servers through HTTP endpoints, so that they might reroute their traffic through a different connection instead. This is an event-driven approach to connectivity resilience.

More event-driven computing on AWS

In addition to SNS, event-driven computing is also addressed by Amazon CloudWatch Events, which delivers a near real-time stream of system events that describe changes in AWS resources. With CloudWatch Events, you can route each event type to one or more targets, including:

Many AWS services publish events to CloudWatch. As an example, you can get CloudWatch Events to capture events on your ETL (Extract, Transform, Load) jobs running on AWS Glue and push failed ones to an SQS queue, so that you can retry them later.

Conclusion

Amazon SNS is a pub/sub messaging service that can be used as an event-driven computing hub to AWS customers worldwide. By capturing events natively triggered by AWS services, such as EC2, S3 and RDS, you can automate and optimize all kinds of workflows, namely scaling, testing, encoding, profiling, broadcasting, discovery, failover, and much more. Business use cases presented in this post ranged from recruiting websites, to scientific research, geographic systems, social networks, retail websites, and news portals.

Start now by visiting Amazon SNS in the AWS Management Console, or by trying the AWS 10-Minute Tutorial, Send Fan-out Event Notifications with Amazon SNS and Amazon SQS.