Tag Archives: AWS AppSync

Building well-architected serverless applications: Optimizing application costs

Post Syndicated from Julian Wood original https://aws.amazon.com/blogs/compute/building-well-architected-serverless-applications-optimizing-application-costs/

This series of blog posts uses the AWS Well-Architected Tool with the Serverless Lens to help customers build and operate applications using best practices. In each post, I address the serverless-specific questions identified by the Serverless Lens along with the recommended best practices. See the introduction post for a table of contents and explanation of the example application.

COST 1. How do you optimize your serverless application costs?

Design, implement, and optimize your application to maximize value. Asynchronous design patterns and performance practices ensure efficient resource use and directly impact the value per business transaction. By optimizing your serverless application performance and its code patterns, you can directly impact the value it provides, while making more efficient use of resources.

Serverless architectures are easier to manage in terms of correct resource allocation compared to traditional architectures. Due to its pay-per-value pricing model and scale based on demand, a serverless approach effectively reduces the capacity planning effort. As covered in the operational excellence and performance pillars, optimizing your serverless application has a direct impact on the value it produces and its cost. For general serverless optimization guidance, see the AWS re:Invent talks, “Optimizing your Serverless applications” Part 1 and Part 2, and “Serverless architectural patterns and best practices”.

Required practice: Minimize external calls and function code initialization

AWS Lambda functions may call other managed services and third-party APIs. Functions may also use application dependencies that may not be suitable for ephemeral environments. Understanding and controlling what your function accesses while it runs can have a direct impact on value provided per invocation.

Review code initialization

I explain the Lambda initialization process with cold and warm starts in “Optimizing application performance – part 1”. Lambda reports the time it takes to initialize application code in Amazon CloudWatch Logs. As Lambda functions are billed by request and duration, you can use this to track costs and performance. Consider reviewing your application code and its dependencies to improve the overall execution time to maximize value.

You can take advantage of Lambda execution environment reuse to make external calls to resources and use the results for subsequent invocations. Use TTL mechanisms inside your function handler code. This ensures that you can prevent additional external calls that incur additional execution time, while preemptively fetching data that isn’t stale.

Review third-party application deployments and permissions

When using Lambda layers or applications provisioned by AWS Serverless Application Repository, be sure to understand any associated charges that these may incur. When deploying functions packaged as container images, understand the charges for storing images in Amazon Elastic Container Registry (ECR).

Ensure that your Lambda function only has access to what its application code needs. Regularly review that your function has a predicted usage pattern so you can factor in the cost of other services, such as Amazon S3 and Amazon DynamoDB.

Required practice: Optimize logging output and its retention

Considering reviewing your application logging level. Ensure that logging output and log retention are appropriately set to your operational needs to prevent unnecessary logging and data retention. This helps you have the minimum of log retention to investigate operational and performance inquiries when necessary.

Emit and capture only what is necessary to understand and operate your component as intended.

With Lambda, any standard output statements are sent to CloudWatch Logs. Capture and emit business and operational events that are necessary to help you understand your function, its integration, and its interactions. Use a logging framework and environment variables to dynamically set a logging level. When applicable, sample debugging logs for a percentage of invocations.

In the serverless airline example used in this series, the booking service Lambda functions use Lambda Powertools as a logging framework with output structured as JSON.

Lambda Powertools is added to the Lambda functions as a shared Lambda layer in the AWS Serverless Application Model (AWS SAM) template. The layer ARN is stored in Systems Manager Parameter Store.

Parameters:
  SharedLibsLayer:
    Type: AWS::SSM::Parameter::Value<String>
    Description: Project shared libraries Lambda Layer ARN
Resources:
    ConfirmBooking:
        Type: AWS::Serverless::Function
        Properties:
            FunctionName: !Sub ServerlessAirline-ConfirmBooking-${Stage}
            Handler: confirm.lambda_handler
            CodeUri: src/confirm-booking
            Layers:
                - !Ref SharedLibsLayer
            Runtime: python3.7
…

The LOG_LEVEL and other Powertools settings are configured in the Globals section as Lambda environment variable for all functions.

Globals:
    Function:
        Environment:
            Variables:
                POWERTOOLS_SERVICE_NAME: booking
                POWERTOOLS_METRICS_NAMESPACE: ServerlessAirline
                LOG_LEVEL: INFO

For Amazon API Gateway, there are two types of logging in CloudWatch: execution logging and access logging. Execution logs contain information that you can use to identify and troubleshoot API errors. API Gateway manages the CloudWatch Logs, creating the log groups and log streams. Access logs contain details about who accessed your API and how they accessed it. You can create your own log group or choose an existing log group that could be managed by API Gateway.

Enable access logs, and selectively review the output format and request fields that might be necessary. For more information, see “Setting up CloudWatch logging for a REST API in API Gateway”.

API Gateway logging

API Gateway logging

Enable AWS AppSync logging which uses CloudWatch to monitor and debug requests. You can configure two types of logging: request-level and field-level. For more information, see “Monitoring and Logging”.

AWS AppSync logging

AWS AppSync logging

Define and set a log retention strategy

Define a log retention strategy to satisfy your operational and business needs. Set log expiration for each CloudWatch log group as they are kept indefinitely by default.

For example, in the booking service AWS SAM template, log groups are explicitly created for each Lambda function with a parameter specifying the retention period.

Parameters:
    LogRetentionInDays:
        Type: Number
        Default: 14
        Description: CloudWatch Logs retention period
Resources:
    ConfirmBookingLogGroup:
        Type: AWS::Logs::LogGroup
        Properties:
            LogGroupName: !Sub "/aws/lambda/${ConfirmBooking}"
            RetentionInDays: !Ref LogRetentionInDays

The Serverless Application Repository application, auto-set-log-group-retention can update the retention policy for new and existing CloudWatch log groups to the specified number of days.

For log archival, you can export CloudWatch Logs to S3 and store them in Amazon S3 Glacier for more cost-effective retention. You can use CloudWatch Log subscriptions for custom processing, analysis, or loading to other systems. Lambda extensions allows you to process, filter, and route logs directly from Lambda to a destination of your choice.

Good practice: Optimize function configuration to reduce cost

Benchmark your function using a different set of memory size

For Lambda functions, memory is the capacity unit for controlling the performance and cost of a function. You can configure the amount of memory allocated to a Lambda function, between 128 MB and 10,240 MB. The amount of memory also determines the amount of virtual CPU available to a function. Benchmark your AWS Lambda functions with differing amounts of memory allocated. Adding more memory and proportional CPU may lower the duration and reduce the cost of each invocation.

In “Optimizing application performance – part 2”, I cover using AWS Lambda Power Tuning to automate the memory testing process to balances performance and cost.

Best practice: Use cost-aware usage patterns in code

Reduce the time your function runs by reducing job-polling or task coordination. This avoids overpaying for unnecessary compute time.

Decide whether your application can fit an asynchronous pattern

Avoid scenarios where your Lambda functions wait for external activities to complete. I explain the difference between synchronous and asynchronous processing in “Optimizing application performance – part 1”. You can use asynchronous processing to aggregate queues, streams, or events for more efficient processing time per invocation. This reduces wait times and latency from requesting apps and functions.

Long polling or waiting increases the costs of Lambda functions and also reduces overall account concurrency. This can impact the ability of other functions to run.

Consider using other services such as AWS Step Functions to help reduce code and coordinate asynchronous workloads. You can build workflows using state machines with long-polling, and failure handling. Step Functions also supports direct service integrations, such as DynamoDB, without having to use Lambda functions.

In the serverless airline example used in this series, Step Functions is used to orchestrate the Booking microservice. The ProcessBooking state machine handles all the necessary steps to create bookings, including payment.

Booking service state machine

Booking service state machine

To reduce costs and improves performance with CloudWatch, create custom metrics asynchronously. You can use the Embedded Metrics Format to write logs, rather than the PutMetricsData API call. I cover using the embedded metrics format in “Understanding application health” – part 1 and part 2.

For example, once a booking is made, the logs are visible in the CloudWatch console. You can select a log stream and find the custom metric as part of the structured log entry.

Custom metric structured log entry

Custom metric structured log entry

CloudWatch automatically creates metrics from these structured logs. You can create graphs and alarms based on them. For example, here is a graph based on a BookingSuccessful custom metric.

CloudWatch metrics custom graph

CloudWatch metrics custom graph

Consider asynchronous invocations and review run away functions where applicable

Take advantage of Lambda’s event-based model. Lambda functions can be triggered based on events ingested into Amazon Simple Queue Service (SQS) queues, S3 buckets, and Amazon Kinesis Data Streams. AWS manages the polling infrastructure on your behalf with no additional cost. Avoid code that polls for third-party software as a service (SaaS) providers. Rather use Amazon EventBridge to integrate with SaaS instead when possible.

Carefully consider and review recursion, and establish timeouts to prevent run away functions.

Conclusion

Design, implement, and optimize your application to maximize value. Asynchronous design patterns and performance practices ensure efficient resource use and directly impact the value per business transaction. By optimizing your serverless application performance and its code patterns, you can reduce costs while making more efficient use of resources.

In this post, I cover minimizing external calls and function code initialization. I show how to optimize logging output with the embedded metrics format, and log retention. I recap optimizing function configuration to reduce cost and highlight the benefits of asynchronous event-driven patterns.

This post wraps up the series, building well-architected serverless applications, where I cover the AWS Well-Architected Tool with the Serverless Lens . See the introduction post for links to all the blog posts.

For more serverless learning resources, visit Serverless Land.

 

Building well-architected serverless applications: Building in resiliency – part 2

Post Syndicated from Julian Wood original https://aws.amazon.com/blogs/compute/building-well-architected-serverless-applications-building-in-resiliency-part-2/

This series of blog posts uses the AWS Well-Architected Tool with the Serverless Lens to help customers build and operate applications using best practices. In each post, I address the serverless-specific questions identified by the Serverless Lens along with the recommended best practices. See the introduction post for a table of contents and explanation of the example application.

Reliability question REL2: How do you build resiliency into your serverless application?

This post continues part 1 of this reliability question. Previously, I cover managing failures using retries, exponential backoff, and jitter. I explain how DLQs can isolate failed messages. I show how to use state machines to orchestrate long running transactions rather than handling these in application code.

Required practice: Manage duplicate and unwanted events

Duplicate events can occur when a request is retried or multiple consumers process the same message from a queue or stream. A duplicate can also happen when a request is sent twice at different time intervals with the same parameters. Design your applications to process multiple identical requests to have the same effect as making a single request.

Idempotency refers to the capacity of an application or component to identify repeated events and prevent duplicated, inconsistent, or lost data. This means that receiving the same event multiple times does not change the result beyond the first time the event was received. An idempotent application can, for example, handle multiple identical refund operations. The first refund operation is processed. Any further refund requests to the same customer with the same payment reference should not be processes again.

When using AWS Lambda, you can make your function idempotent. The function’s code must properly validate input events and identify if the events were processed before. For more information, see “How do I make my Lambda function idempotent?”

When processing streaming data, your application must anticipate and appropriately handle processing individual records multiple times. There are two primary reasons why records may be delivered more than once to your Amazon Kinesis Data Streams application: producer retries and consumer retries. For more information, see “Handling Duplicate Records”.

Generate unique attributes to manage duplicate events at the beginning of the transaction

Create, or use an existing unique identifier at the beginning of a transaction to ensure idempotency. These identifiers are also known as idempotency tokens. A number of Lambda triggers include a unique identifier as part of the event:

You can also create your own identifiers. These can be business-specific, such as transaction ID, payment ID, or booking ID. You can use an opaque random alphanumeric string, unique correlation identifiers, or the hash of the content.

A Lambda function, for example can use these identifiers to check whether the event has been previously processed.

Depending on the final destination, duplicate events might write to the same record with the same content instead of generating a duplicate entry. This may therefore not require additional safeguards.

Use an external system to store unique transaction attributes and verify for duplicates

Lambda functions can use Amazon DynamoDB to store and track transactions and idempotency tokens to determine if the transaction has been handled previously. DynamoDB Time to Live (TTL) allows you to define a per-item timestamp to determine when an item is no longer needed. This helps to limit the storage space used. Base the TTL on the event source. For example, the message retention period for SQS.

Using DynamoDB to store idempotent tokens

Using DynamoDB to store idempotent tokens

You can also use DynamoDB conditional writes to ensure a write operation only succeeds if an item attribute meets one of more expected conditions. For example, you can use this to fail a refund operation if a payment reference has already been refunded. This signals to the application that it is a duplicate transaction. The application can then catch this exception and return the same result to the customer as if the refund was processed successfully.

Third-party APIs can also support idempotency directly. For example, Stripe allows you to add an Idempotency-Key: <key> header to the request. Stripe saves the resulting status code and body of the first request made for any given idempotency key, regardless of whether it succeeded or failed. Subsequent requests with the same key return the same result.

Validate events using a pre-defined and agreed upon schema

Implicitly trusting data from clients, external sources, or machines could lead to malformed data being processed. Use a schema to validate your event conforms to what you are expecting. Process the event using the schema within your application code or at the event source when applicable. Events not adhering to your schema should be discarded.

For API Gateway, I cover validating incoming HTTP requests against a schema in “Implementing application workload security – part 1”.

Amazon EventBridge rules match event patterns. EventBridge provides schemas for all events that are generated by AWS services. You can create or upload custom schemas or infer schemas directly from events on an event bus. You can also generate code bindings for event schemas.

SNS supports message filtering. This allows a subscriber to receive a subset of the messages sent to the topic using a filter policy. For more information, see the documentation.

JSON Schema is a tool for validating the structure of JSON documents. There are a number of implementations available.

Best practice: Consider scaling patterns at burst rates

Load testing your serverless application allows you to monitor the performance of an application before it is deployed to production. Serverless applications can be simpler to load test, thanks to the automatic scaling built into many of the services. For more information, see “How to design Serverless Applications for massive scale”.

In addition to your baseline performance, consider evaluating how your workload handles initial burst rates. This ensures that your workload can sustain burst rates while scaling to meet possibly unexpected demand.

Perform load tests using a burst strategy with random intervals of idleness

Perform load tests using a burst of requests for a short period of time. Also introduce burst delays to allow your components to recover from unexpected load. This allows you to future-proof the workload for key events when you do not know peak traffic levels.

There are a number of AWS Marketplace and AWS Partner Network (APN) solutions available for performance testing, including Gatling FrontLine, BlazeMeter, and Apica.

In regulating inbound request rates – part 1, I cover running a performance test suite using Gatling, an open source tool.

Gatling performance results

Gatling performance results

Amazon does have a network stress testing policy that defines which high volume network tests are allowed. Tests that purposefully attempt to overwhelm the target and/or infrastructure are considered distributed denial of service (DDoS) tests and are prohibited. For more information, see “Amazon EC2 Testing Policy”.

Review service account limits with combined utilization across resources

AWS accounts have default quotas, also referred to as limits, for each AWS service. These are generally Region-specific. You can request increases for some limits while other limits cannot be increased. Service Quotas is an AWS service that helps you manage your limits for many AWS services. Along with looking up the values, you can also request a limit increase from the Service Quotas console.

Service Quotas dashboard

Service Quotas dashboard

As these limits are shared within an account, review the combined utilization across resources including the following:

  • Amazon API Gateway: number of requests per second across all APIs. (link)
  • AWS AppSync: throttle rate limits. (link)
  • AWS Lambda: function concurrency reservations and pool capacity to allow other functions to scale. (link)
  • Amazon CloudFront: requests per second per distribution. (link)
  • AWS IoT Core message broker: concurrent requests per second. (link)
  • Amazon EventBridge: API requests and target invocations limit. (link)
  • Amazon Cognito: API limits. (link)
  • Amazon DynamoDB: throughput, indexes, and request rates limits. (link)

Evaluate key metrics to understand how workloads recover from bursts

There are a number of key Amazon CloudWatch metrics to evaluate and alert on to understand whether your workload recovers from bursts.

  • AWS Lambda: Duration, Errors, Throttling, ConcurrentExecutions, UnreservedConcurrentExecutions. (link)
  • Amazon API Gateway: Latency, IntegrationLatency, 5xxError, 4xxError. (link)
  • Application Load Balancer: HTTPCode_ELB_5XX_Count, RejectedConnectionCount, HTTPCode_Target_5XX_Count, UnHealthyHostCount, LambdaInternalError, LambdaUserError. (link)
  • AWS AppSync: 5XX, Latency. (link)
  • Amazon SQS: ApproximateAgeOfOldestMessage. (link)
  • Amazon Kinesis Data Streams: ReadProvisionedThroughputExceeded, WriteProvisionedThroughputExceeded, GetRecords.IteratorAgeMilliseconds, PutRecord.Success, PutRecords.Success (if using Kinesis Producer Library), GetRecords.Success. (link)
  • Amazon SNS: NumberOfNotificationsFailed, NumberOfNotificationsFilteredOut-InvalidAttributes. (link)
  • Amazon Simple Email Service (SES): Rejects, Bounces, Complaints, Rendering Failures. (link)
  • AWS Step Functions: ExecutionThrottled, ExecutionsFailed, ExecutionsTimedOut. (link)
  • Amazon EventBridge: FailedInvocations, ThrottledRules. (link)
  • Amazon S3: 5xxErrors, TotalRequestLatency. (link)
  • Amazon DynamoDB: ReadThrottleEvents, WriteThrottleEvents, SystemErrors, ThrottledRequests, UserErrors. (link)

Conclusion

This post continues from part 1 and looks at managing duplicate and unwanted events with idempotency and an event schema. I cover how to consider scaling patterns at burst rates by managing account limits and show relevant metrics to evaluate

Build resiliency into your workloads. Ensure that applications can withstand partial and intermittent failures across components that may only surface in production. In the next post in the series, I cover the performance efficiency pillar from the Well-Architected Serverless Lens.

For more serverless learning resources, visit Serverless Land.

Building well-architected serverless applications: Managing application security boundaries – part 2

Post Syndicated from Julian Wood original https://aws.amazon.com/blogs/compute/building-well-architected-serverless-applications-managing-application-security-boundaries-part-2/

This series uses the AWS Well-Architected Tool with the Serverless Lens to help customers build and operate applications using best practices. In each post, I address the nine serverless-specific questions identified by the Serverless Lens along with the recommended best practices. See the introduction post for a table of contents and explanation of the example application.

Security question SEC2: How do you manage your serverless application’s security boundaries?

This post continues part 1 of this security question. Previously, I cover how to evaluate and define resource policies, showing what policies are available for various serverless services. I show some of the features of AWS Web Application Firewall (AWS WAF) to protect APIs. Then then go through how to control network traffic at all layers. I explain how AWS Lambda functions connect to VPCs, and how to use private APIs and VPC endpoints. I walk through how to audit your traffic.

Required practice: Use temporary credentials between resources and components

Do not share credentials and permissions policies between resources to maintain a granular segregation of permissions and improve the security posture. Use temporary credentials that are frequently rotated and that have policies tailored to the access the resource needs.

Use dynamic authentication when accessing components and managed services

AWS Identity and Access Management (IAM) roles allows your applications to access AWS services securely without requiring you to manage or hardcode the security credentials. When you use a role, you don’t have to distribute long-term credentials such as a user name and password, or access keys. Instead, the role supplies temporary permissions that applications can use when they make calls to other AWS resources. When you create a Lambda function, for example, you specify an IAM role to associate with the function. The function can then use the role-supplied temporary credentials to sign API requests.

Use IAM for authorizing access to AWS managed services such as Lambda or Amazon S3. Lambda also assumes IAM roles, exposing and rotating temporary credentials to your functions. This enables your application code to access AWS services.

Use IAM to authorize access to internal or private Amazon API Gateway API consumers. See this list of AWS services that work with IAM.

Within the serverless airline example used in this series, the loyalty service uses a Lambda function to fetch loyalty points and next tier progress. AWS AppSync acts as the client using an HTTP resolver, via an API Gateway REST API /loyalty/{customerId}/get resource, to invoke the function.

To ensure only AWS AppSync is authorized to invoke the API, IAM authorization is set within the API Gateway method request.

Viewing API Gateway IAM authorization

Viewing API Gateway IAM authorization

The IAM role specifies that appsync.amazonaws.com can perform an execute-api:Invoke on the specific API Gateway resource arn:aws:execute-api:${AWS::Region}:${AWS::AccountId}:${LoyaltyApi}/*/*/*

For more information, see “Using an IAM role to grant permissions to applications”.

Use a framework such as the AWS Serverless Application Model (AWS SAM) to deploy your applications. This ensures that AWS resources are provisioned with unique per resource IAM roles. For example, AWS SAM automatically creates unique IAM roles for every Lambda function you create.

Best practice: Design smaller, single purpose functions

Creating smaller, single purpose functions enables you to keep your permissions aligned to least privileged access. This reduces the risk of compromise since the function does not require access to more than it needs.

Create single purpose functions with their own IAM role

Single purpose Lambda functions allow you to create IAM roles that are specific to your access requirements. For example, a large multipurpose function might need access to multiple AWS resources such as Amazon DynamoDB, Amazon S3, and Amazon Simple Queue Service (SQS). Single purpose functions would not need access to all of them at the same time.

With smaller, single purpose functions, it’s often easier to identify the specific resources and access requirements, and grant only those permissions. Additionally, new features are usually implemented by new functions in this architectural design. You can specifically grant permissions in new IAM roles for these functions.

Avoid sharing IAM roles with multiple cloud resources. As permissions are added to the role, these are shared across all resources using this role. For example, use one dedicated IAM role per Lambda function. This allows you to control permissions more intentionally. Even if some functions have the same policy initially, always separate the IAM roles to ensure least privilege policies.

Use least privilege access policies with your users and roles

When you create IAM policies, follow the standard security advice of granting least privilege, or granting only the permissions required to perform a task. Determine what users (and roles) must do and then craft policies that allow them to perform only those tasks.

Start with a minimum set of permissions and grant additional permissions as necessary. Doing so is more secure than starting with permissions that are too lenient and then trying to tighten them later. In the unlikely event of misused credentials, credentials will only be able to perform limited interactions.

To control access to AWS resources, AWS SAM uses the same mechanisms as AWS CloudFormation. For more information, see “Controlling access with AWS Identity and Access Management” in the AWS CloudFormation User Guide.

For a Lambda function, AWS SAM scopes the permissions of your Lambda functions to the resources that are used by your application. You add IAM policies as part of the AWS SAM template. The policies property can be the name of AWS managed policies, inline IAM policy documents, or AWS SAM policy templates.

For example, the serverless airline has a ConfirmBooking Lambda function that has UpdateItem permissions to the specific DynamoDB BookingTable resource.

Parameters:
    BookingTable:
        Type: AWS::SSM::Parameter::Value<String>
        Description: Parameter Name for Booking Table
Resources:
    ConfirmBooking:
        Type: AWS::Serverless::Function
        Properties:
            FunctionName: !Sub ServerlessAirline-ConfirmBooking-${Stage}
            Policies:
                - Version: "2012-10-17"
                  Statement:
                      Action: dynamodb:UpdateItem
                      Effect: Allow
                      Resource: !Sub "arn:${AWS::Partition}:dynamodb:${AWS::Region}:${AWS::AccountId}:table/${BookingTable}"

One of the fastest ways to scope permissions appropriately is to use AWS SAM policy templates. You can reference these templates directly in the AWS SAM template for your application, providing custom parameters as required.

The serverless patterns collection allows you to build integrations quickly using AWS SAM and AWS Cloud Development Kit (AWS CDK) templates.

The booking service uses the SNSPublishMessagePolicy. This policy gives permission to the NotifyBooking Lambda function to publish a message to an Amazon Simple Notification Service (Amazon SNS) topic.

    BookingTopic:
        Type: AWS::SNS::Topic

    NotifyBooking:
        Type: AWS::Serverless::Function
        Properties:
            Policies:
                - SNSPublishMessagePolicy:
                      TopicName: !Sub ${BookingTopic.TopicName}
        …

Auditing permissions and removing unnecessary permissions

Audit permissions regularly to help you identify unused permissions so that you can remove them. You can use last accessed information to refine your policies and allow access to only the services and actions that your entities use. Use the IAM console to view when last an IAM role was used.

IAM last used

IAM last used

Use IAM access advisor to review when was the last time an AWS service was used from a specific IAM user or role. You can view last accessed information for IAM on the Access Advisor tab in the IAM console. Using this information, you can remove IAM policies and access from your IAM roles.

IAM access advisor

IAM access advisor

When creating and editing policies, you can validate them using IAM Access Analyzer, which provides over 100 policy checks. It generates security warnings when a statement in your policy allows access AWS considers overly permissive. Use the security warning’s actionable recommendations to help grant least privilege. To learn more about policy checks provided by IAM Access Analyzer, see “IAM Access Analyzer policy validation”.

With AWS CloudTrail, you can use CloudTrail event history to review individual actions your IAM role has performed in the past. Using this information, you can detect which permissions were actively used, and decide to remove permissions.

AWS CloudTrail

AWS CloudTrail

To work out which permissions you may need, you can generate IAM policies based on access activity. You configure an IAM role with broad permissions while the application is in development. Access Analyzer reviews your CloudTrail logs. It generates a policy template that contains the permissions that the role used in your specified date range. Use the template to create a policy that grants only the permissions needed to support your specific use case. For more information, see “Generate policies based on access activity”.

IAM Access Analyzer

IAM Access Analyzer

Conclusion

Managing your serverless application’s security boundaries ensures isolation for, within, and between components. In this post, I continue from part 1, looking at using temporary credentials between resources and components. I cover why smaller, single purpose functions are better from a security perspective, and how to audit permissions. I show how to use AWS SAM to create per-function IAM roles.

For more serverless learning resources, visit https://serverlessland.com.

Building well-architected serverless applications: Managing application security boundaries – part 1

Post Syndicated from Julian Wood original https://aws.amazon.com/blogs/compute/building-well-architected-serverless-applications-managing-application-security-boundaries-part-1/

This series of blog posts uses the AWS Well-Architected Tool with the Serverless Lens to help customers build and operate applications using best practices. In each post, I address the serverless-specific questions identified by the Serverless Lens along with the recommended best practices. See the introduction post for a table of contents and explanation of the example application.

Security question SEC2: How do you manage your serverless application’s security boundaries?

Defining and securing your serverless application’s boundaries ensures isolation for, within, and between components.

Required practice: Evaluate and define resource policies

Resource policies are AWS Identity and Access Management (IAM) statements. They are attached to resources such as an Amazon S3 bucket, or an Amazon API Gateway REST API resource or method. The policies define what identities have fine-grained access to the resource. To see which services support resource-based policies, see “AWS Services That Work with IAM”. For more information on how resource policies and identity policies are evaluated, see “Identity-Based Policies and Resource-Based Policies”.

Understand and determine which resource policies are necessary

Resource policies can protect a component by restricting inbound access to managed services. Use resource policies to restrict access to your component based on a number of identities, such as the source IP address/range, function event source, version, alias, or queues. Resource policies are evaluated and enforced at IAM level before each AWS service applies it’s own authorization mechanisms, when available. For example, IAM resource policies for API Gateway REST APIs can deny access to an API before an AWS Lambda authorizer is called.

If you use multiple AWS accounts, you can use AWS Organizations to manage and govern individual member accounts centrally. Certain resource policies can be applied at the organizations level, providing guardrail for what actions AWS accounts within the organization root or OU can do. For more information see, “Understanding how AWS Organization Service Control Policies work”.

Review your existing policies and how they’re configured, paying close attention to how permissive individual policies are. Your resource policies should only permit necessary callers.

Implement resource policies to prevent unauthorized access

For Lambda, use resource-based policies to provide fine-grained access to what AWS IAM identities and event sources can invoke a specific version or alias of your function. Resource-based policies can also be used to control access to Lambda layers. You can combine resource policies with Lambda event sources. For example, if API Gateway invokes Lambda, you can restrict the policy to the API Gateway ID, HTTP method, and path of the request.

In the serverless airline example used in this series, the IngestLoyalty service uses a Lambda function that subscribes to an Amazon Simple Notification Service (Amazon SNS) topic. The Lambda function resource policy allows SNS to invoke the Lambda function.

Lambda resource policy document

Lambda resource policy document

API Gateway resource-based policies can restrict API access to specific Amazon Virtual Private Cloud (VPC), VPC endpoint, source IP address/range, AWS account, or AWS IAM users.

Amazon Simple Queue Service (SQS) resource-based policies provide fine-grained access to certain AWS services and AWS IAM identities (users, roles, accounts). Amazon SNS resource-based policies restrict authenticated and non-authenticated actions to topics.

Amazon DynamoDB resource-based policies provide fine-grained access to tables and indexes. Amazon EventBridge resource-based policies restrict AWS identities to send and receive events including to specific event buses.

For Amazon S3, use bucket policies to grant permission to your Amazon S3 resources.

The AWS re:Invent session Best practices for growing a serverless application includes further suggestions on enforcing security best practices.

Best practices for growing a serverless application

Best practices for growing a serverless application

Good practice: Control network traffic at all layers

Apply controls for controlling both inbound and outbound traffic, including data loss prevention. Define requirements that help you protect your networks and protect against exfiltration.

Use networking controls to enforce access patterns

API Gateway and AWS AppSync have support for AWS Web Application Firewall (AWS WAF) which helps protect web applications and APIs from attacks. AWS WAF enables you to configure a set of rules called a web access control list (web ACL). These allow you to block, or count web requests based on customizable web security rules and conditions that you define. These can include specified IP address ranges, CIDR blocks, specific countries, or Regions. You can also block requests that contain malicious SQL code, or requests that contain malicious script. For more information, see How AWS WAF Works.

A private API endpoint is an API Gateway interface VPC endpoint that can only be accessed from your Amazon Virtual Private Cloud (Amazon VPC). This is an elastic network interface that you create in a VPC. Traffic to your private API uses secure connections and does not leave the Amazon network, it is isolated from the public internet. For more information, see “Creating a private API in Amazon API Gateway”.

To restrict access to your private API to specific VPCs and VPC endpoints, you must add conditions to your API’s resource policy. For example policies, see the documentation.

By default, Lambda runs your functions in a secure Lambda-owned VPC that is not connected to your account’s default VPC. Functions can access anything available on the public internet. This includes other AWS services, HTTPS endpoints for APIs, or services and endpoints outside AWS. The function cannot directly connect to your private resources inside of your VPC.

You can configure a Lambda function to connect to private subnets in a VPC in your account. When a Lambda function is configured to use a VPC, the Lambda function still runs inside the Lambda service VPC. The function then sends all network traffic through your VPC and abides by your VPC’s network controls. Functions deployed to virtual private networks must consider network access to restrict resource access.

AWS Lambda service VPC with VPC-to-VPT NAT to customer VPC

AWS Lambda service VPC with VPC-to-VPT NAT to customer VPC

When you connect a function to a VPC in your account, the function cannot access the internet, unless the VPC provides access. To give your function access to the internet, route outbound traffic to a NAT gateway in a public subnet. The NAT gateway has a public IP address and can connect to the internet through the VPC’s internet gateway. For more information, see “How do I give internet access to my Lambda function in a VPC?”. Connecting a function to a public subnet doesn’t give it internet access or a public IP address.

You can control the VPC settings for your Lambda functions using AWS IAM condition keys. For example, you can require that all functions in your organization are connected to a VPC. You can also specify the subnets and security groups that the function’s users can and can’t use.

Unsolicited inbound traffic to a Lambda function isn’t permitted by default. There is no direct network access to the execution environment where your functions run. When connected to a VPC, function outbound traffic comes from your own network address space.

You can use security groups, which act as a virtual firewall to control outbound traffic for functions connected to a VPC. Use security groups to permit your Lambda function to communicate with other AWS resources. For example, a security group can allow the function to connect to an Amazon ElastiCache cluster.

To filter or block access to certain locations, use VPC routing tables to configure routing to different networking appliances. Use network ACLs to block access to CIDR IP ranges or ports, if necessary. For more information about the differences between security groups and network ACLs, see “Compare security groups and network ACLs.”

In addition to API Gateway private endpoints, several AWS services offer VPC endpoints, including Lambda. You can use VPC endpoints to connect to AWS services from within a VPC without an internet gateway, NAT device, VPN connection, or AWS Direct Connect connection.

Using tools to audit your traffic

When you configure a Lambda function to use a VPC, or use private API endpoints, you can use VPC Flow Logs to audit your traffic. VPC Flow Logs allow you to capture information about the IP traffic going to and from network interfaces in your VPC. Flow log data can be published to Amazon CloudWatch Logs or S3 to see where traffic is being sent to at a granular level. Here are some flow log record examples. For more information, see “Learn from your VPC Flow Logs”.

Block network access when required

In addition to security groups and network ACLs, third-party tools allow you to disable outgoing VPC internet traffic. These can also be configured to allow traffic to AWS services or allow-listed services.

Conclusion

Managing your serverless application’s security boundaries ensures isolation for, within, and between components. In this post, I cover how to evaluate and define resource policies, showing what policies are available for various serverless services. I show some of the features of AWS WAF to protect APIs. Then I review how to control network traffic at all layers. I explain how Lambda functions connect to VPCs, and how to use private APIs and VPC endpoints. I walk through how to audit your traffic.

This well-architected question will be continued where I look at using temporary credentials between resources and components. I cover why smaller, single purpose functions are better from a security perspective, and how to audit permissions. I show how to use AWS Serverless Application Model (AWS SAM) to create per-function IAM roles.

For more serverless learning resources, visit https://serverlessland.com.

Scaling Neuroscience Research on AWS

Post Syndicated from Konrad Rokicki original https://aws.amazon.com/blogs/architecture/scaling-neuroscience-research-on-aws/

HHMI’s Janelia Research Campus in Ashburn, Virginia has an integrated team of lab scientists and tool-builders who pursue a small number of scientific questions with potential for transformative impact. To drive science forward, we share our methods, results, and tools with the scientific community.

Introduction

Our neuroscience research application involves image searches that are computationally intensive but have unpredictable and sporadic usage patterns. The conventional on-premises approach is to purchase a powerful and expensive workstation, install and configure specialized software, and download the entire dataset to local storage. With 16 cores, a typical search of 50,000 images takes 30 seconds. A serverless architecture using AWS Lambda allows us to do this job in seconds for a few cents per search, and is capable of scaling to larger datasets.

Parallel Computation in Neuroscience Research

Basic research in neuroscience is often conducted on fruit flies. This is because their brains are small enough to study in a meaningful way with current tools, but complex enough to produce sophisticated behaviors. Conducting such research nonetheless requires an immense amount of data and computational power. Janelia Research Campus developed the NeuronBridge tool on AWS to accelerate scientific discovery by scaling computation in the cloud.

Color Depth Search Example fly brains

Figure 1: A “mask image” (on the left) is compared to many different fly brains (on the right) to find matching neurons. (Janella Research Campus)

The fruit fly (Drosophila melanogaster) has about 100,000 neurons and its brain is highly stereotyped. This means that the brain of one fruit fly is similar to the next one. Using electron microscopy (EM), the FlyEM project has reconstructed a wiring diagram of a fruit fly brain. This connectome includes the structure of the neurons and the connectivity between them. But EM is only half of the picture. Once scientists know the structure and connectivity, they must perform experiments to find what purpose the neurons serve.

Flies can be genetically modified to reproducibly express a fluorescent protein in certain neurons, causing those neurons to glow under a light microscope (LM). By iterating through many modifications, the FlyLight project has created a vast genetic driver library. This allows scientists to target individual neurons for experiments. For example, blocking a particular neuron of a fly from functioning, and then observing its behavior, allows a scientist to understand the function of that neuron. Through the course of many such experiments, scientists are currently uncovering the function of entire neuronal circuits.

We developed NeuronBridge, a tool available for use by neuroscience researchers around the world, to bridge the gap between the EM and LM data. Scientists can start with EM structure and find matching fly lines in LM. Or they may start with a fly line and find the corresponding neuronal circuits in the EM connectome.

Both EM and LM produce petabytes of 3D images. Image processing and machine learning algorithms are then applied to discern neuron structure. We also developed a computational shortcut called color depth MIP to represent depth as color. This technique compresses large 3D image stacks into smaller 2D images that can be searched efficiently.

Image search is an embarrassingly parallel problem ideally suited to parallelization with simple functions. In a typical search, the scientist will create a “mask image,” which is a color depth image featuring only the neuron they want to find. The search algorithm must then compare this image to hundreds of thousands of other images. The paradigm of launching many short-lived cloud workers, termed burst-parallel compute, was originally suggested by a group at UCSD. To scale NeuronBridge, we decided to build a serverless AWS-native implementation of burst-parallel image search.

The Architecture

Our main reason for using a serverless approach was that our usage patterns are unpredictable and sporadic. The total number of researchers who are likely to use our tool is not large, and only a small fraction of them will need the tool at any given time. Furthermore, our tool could go unused for weeks at a time, only to get a flood of requests after a new dataset is published. A serverless architecture allows us to cope with this unpredictable load. We can keep costs low by only paying for the compute time we actually use.

One challenge of implementing a burst-parallel architecture is that each Lambda invocation requires a network call, with the ensuing network latency. Spawning several thousands of functions from a single manager function can take many seconds. The trick to minimizing this latency is to parallelize these calls by recursively spawning concurrent managers in a tree structure. Each leaf in this tree spawns a set of worker functions to do the work of searching the imagery. Each worker reads a small batch of images from Amazon Simple Storage Service (S3). They are then compared to the mask image, and the intermediate results are written to Amazon DynamoDB, a serverless NoSQL database.

Serverless architecture for burst-parallel search

Figure 2: Serverless architecture for burst-parallel search

Search state is monitored by an AWS Step Functions state machine, which checks DynamoDB once per second. When all the results are ready, the Step Functions state machine runs another Lambda function to combine and sort the results. The state machine addresses error conditions and timeouts, and updates the browser when the asynchronous search is complete. We opted to use AWS AppSync to notify a React web client, providing an interactive user experience while remaining entirely serverless.

As we scaled to 3,000 concurrent Lambda functions reading from our data bucket, we reached Amazon S3’s limit of 5,500 GETs per second per prefix. The fix was to create numbered prefix folders and then randomize our key list. Each worker could then search a random list of images across many prefixes. This change distributed the load from our highly parallel functions across a number of S3 shards, and allowed us to run with much higher parallelism.

We also addressed cold-start latency. Infrequently used Lambda functions take longer to start than recently used ones, and our unpredictable usage patterns meant that we were experiencing many cold starts. In our Java functions, we found that most of the cold-start time was attributed to JVM initialization and class loading. Although many mitigations for this exist, our worker logic was small enough that rewriting the code to use Node.js was the obvious choice. This immediately yielded a huge improvement, reducing cold starts from 8-10 seconds down to 200 ms.

With all of these insights, we developed a general-purpose parallel computation framework called burst-compute. This AWS-native framework runs as a serverless application to implement this architecture. It allows you to massively scale your own custom worker functions and combiner functions. We used this new framework to implement our image search.

Conclusion

The burst-parallel architecture is a powerful new computation paradigm for scientific computing. It takes advantage of the enormous scale and technical innovation of the AWS Cloud to provide near-interactive on-demand compute without expensive hardware maintenance costs. As scientific computing capability matures for the cloud, we expect this kind of large-scale parallel computation to continue becoming more accessible. In the future, the cloud could open doors to entirely new types of scientific applications, visualizations, and analysis tools.

We would like to express our thanks to AWS Solutions Architects Scott Glasser and Ray Chang, for their assistance with design and prototyping, and to Geoffrey Meissner for reviewing drafts of this write-up. 

Source Code

All of the application code described in this article is open source and licensed for reuse:

The data and imagery are shared publicly on the Registry of Open Data on AWS.

ICYMI: Serverless pre:Invent 2020

Post Syndicated from James Beswick original https://aws.amazon.com/blogs/compute/icymi-serverless-preinvent-2020/

During the last few weeks, the AWS serverless team has been releasing a wave of new features in the build-up to AWS re:Invent 2020. This post recaps some of the most important releases for serverless developers.

re:Invent is virtual and free to all attendees in 2020 – register here. See the complete list of serverless sessions planned and join the serverless DA team live on Twitch. Also, follow your DAs on Twitter for live recaps and Q&A during the event.

AWS re:Invent 2020

AWS Lambda

We launched Lambda Extensions in preview, enabling you to more easily integrate monitoring, security, and governance tools into Lambda functions. You can also build your own extensions that run code during Lambda lifecycle events, and there is an example extensions repo for starting development.

You can now send logs from Lambda functions to custom destinations by using Lambda Extensions and the new Lambda Logs API. Previously, you could only forward logs after they were written to Amazon CloudWatch Logs. Now, logging tools can receive log streams directly from the Lambda execution environment. This makes it easier to use your preferred tools for log management and analysis, including Datadog, Lumigo, New Relic, Coralogix, Honeycomb, or Sumo Logic.

Lambda Extensions API

Lambda launched support for Amazon MQ as an event source. Amazon MQ is a managed broker service for Apache ActiveMQ that simplifies deploying and scaling queues. This integration increases the range of messaging services that customers can use to build serverless applications. The event source operates in a similar way to using Amazon SQS or Amazon Kinesis. In all cases, the Lambda service manages an internal poller to invoke the target Lambda function.

We also released a new layer to make it simpler to integrate Amazon CodeGuru Profiler. This service helps identify the most expensive lines of code in a function and provides recommendations to help reduce cost. With this update, you can enable the profiler by adding the new layer and setting environment variables. There are no changes needed to the custom code in the Lambda function.

Lambda announced support for AWS PrivateLink. This allows you to invoke Lambda functions from a VPC without traversing the public internet. It provides private connectivity between your VPCs and AWS services. By using VPC endpoints to access the Lambda API from your VPC, this can replace the need for an Internet Gateway or NAT Gateway.

For developers building machine learning inferencing, media processing, high performance computing (HPC), scientific simulations, and financial modeling in Lambda, you can now use AVX2 support to help reduce duration and lower cost. By using packages compiled for AVX2 or compiling libraries with the appropriate flags, your code can then benefit from using AVX2 instructions to accelerate computation. In the blog post’s example, enabling AVX2 for an image-processing function increased performance by 32-43%.

Lambda now supports batch windows of up to 5 minutes when using SQS as an event source. This is useful for workloads that are not time-sensitive, allowing developers to reduce the number of Lambda invocations from queues. Additionally, the batch size has been increased from 10 to 10,000. This is now the same as the batch size for Kinesis as an event source, helping Lambda-based applications process more data per invocation.

Code signing is now available for Lambda, using AWS Signer. This allows account administrators to ensure that Lambda functions only accept signed code for deployment. Using signing profiles for functions, this provides granular control over code execution within the Lambda service. You can learn more about using this new feature in the developer documentation.

Amazon EventBridge

You can now use event replay to archive and replay events with Amazon EventBridge. After configuring an archive, EventBridge automatically stores all events or filtered events, based upon event pattern matching logic. You can configure a retention policy for archives to delete events automatically after a specified number of days. Event replay can help with testing new features or changes in your code, or hydrating development or test environments.

EventBridge archived events

EventBridge also launched resource policies that simplify managing access to events across multiple AWS accounts. This expands the use of a policy associated with event buses to authorize API calls. Resource policies provide a powerful mechanism for modeling event buses across multiple account and providing fine-grained access control to EventBridge API actions.

EventBridge resource policies

EventBridge announced support for Server-Side Encryption (SSE). Events are encrypted using AES-256 at no additional cost for customers. EventBridge also increased PutEvent quotas to 10,000 transactions per second in US East (N. Virginia), US West (Oregon), and Europe (Ireland). This helps support workloads with high throughput.

AWS Step Functions

Synchronous Express Workflows have been launched for AWS Step Functions, providing a new way to run high-throughput Express Workflows. This feature allows developers to receive workflow responses without needing to poll services or build custom solutions. This is useful for high-volume microservice orchestration and fast compute tasks communicating via HTTPS.

The Step Functions service recently added support for other AWS services in workflows. You can now integrate API Gateway REST and HTTP APIs. This enables you to call API Gateway directly from a state machine as an asynchronous service integration.

Step Functions now also supports Amazon EKS service integration. This allows you to build workflows with steps that synchronously launch tasks in EKS and wait for a response. In October, the service also announced support for Amazon Athena, so workflows can now query data in your S3 data lakes.

These new integrations help minimize custom code and provide built-in error handling, parameter passing, and applying recommended security settings.

AWS SAM CLI

The AWS Serverless Application Model (AWS SAM) is an AWS CloudFormation extension that makes it easier to build, manage, and maintains serverless applications. On November 10, the AWS SAM CLI tool released version 1.9.0 with support for cached and parallel builds.

By using sam build --cached, AWS SAM no longer rebuilds functions and layers that have not changed since the last build. Additionally, you can use sam build --parallel to build functions in parallel, instead of sequentially. Both of these new features can substantially reduce the build time of larger applications defined with AWS SAM.

Amazon SNS

Amazon SNS announced support for First-In-First-Out (FIFO) topics. These are used with SQS FIFO queues for applications that require strict message ordering with exactly once processing and message deduplication. This is designed for workloads that perform tasks like bank transaction logging or inventory management. You can also use message filtering in FIFO topics to publish updates selectively.

SNS FIFO

AWS X-Ray

X-Ray now integrates with Amazon S3 to trace upstream requests. If a Lambda function uses the X-Ray SDK, S3 sends tracing headers to downstream event subscribers. With this, you can use the X-Ray service map to view connections between S3 and other services used to process an application request.

AWS CloudFormation

AWS CloudFormation announced support for nested stacks in change sets. This allows you to preview changes in your application and infrastructure across the entire nested stack hierarchy. You can then review those changes before confirming a deployment. This is available in all Regions supporting CloudFormation at no extra charge.

The new CloudFormation modules feature was released on November 24. This helps you develop building blocks with embedded best practices and common patterns that you can reuse in CloudFormation templates. Modules are available in the CloudFormation registry and can be used in the same way as any native resource.

Amazon DynamoDB

For customers using DynamoDB global tables, you can now use your own encryption keys. While all data in DynamoDB is encrypted by default, this feature enables you to use customer managed keys (CMKs). DynamoDB also announced support for global tables in the Europe (Milan) and Europe (Stockholm) Regions. This feature enables you to scale global applications for local access in workloads running in different Regions and replicate tables for higher availability and disaster recovery (DR).

The DynamoDB service announced the ability to export table data to data lakes in Amazon S3. This enables you to use services like Amazon Athena and AWS Lake Formation to analyze DynamoDB data with no custom code required. This feature does not consume table capacity and does not impact performance and availability. To learn how to use this feature, see this documentation.

AWS Amplify and AWS AppSync

You can now use existing Amazon Cognito user pools and identity pools for Amplify projects, making it easier to build new applications for an existing user base. AWS Amplify Console, which provides a fully managed static web hosting service, is now available in the Europe (Milan), Middle East (Bahrain), and Asia Pacific (Hong Kong) Regions. This service makes it simpler to bring automation to deploying and hosting single-page applications and static sites.

AWS AppSync enabled AWS WAF integration, making it easier to protect GraphQL APIs against common web exploits. You can also implement rate-based rules to help slow down brute force attacks. Using AWS Managed Rules for AWS WAF provides a faster way to configure application protection without creating the rules directly. AWS AppSync also recently expanded service availability to the Asia Pacific (Hong Kong), Middle East (Bahrain), and China (Ningxia) Regions, making the service now available in 21 Regions globally.

Still looking for more?

Join the AWS Serverless Developer Advocates on Twitch throughout re:Invent for live Q&A, session recaps, and more! See this page for the full schedule.

For more serverless learning resources, visit Serverless Land.