Building Scalable Applications with AWS Serverless Application Model
Tags: aws, cloud, serverless, devops
Published: 2023-04-28 10:07:28

AWS Serverless Application Model (SAM) is a cool tool that simplifies building scalable serverless apps on Amazon Web Services. It helps developers organize their app resources and services in a structured way. In this article, we'll dive into serverless architecture and show you how to use AWS SAM to build efficient apps on AWS and the benefits of serverless architecture, AWS SAM features, and best practices for designing, testing, and monitoring serverless apps.

## Introduction to AWS Serverless Application Model

The Amazon Web Services Serverless Application Model (SAM) is an open-source architecture for developing serverless applications on Amazon Web Services (AWS). SAM makes it easier to define the Amazon API Gateway APIs, AWS Lambda functions, and Amazon DynamoDB tables that your serverless application requires. You may use AWS CloudFormation syntax to define the infrastructure for your serverless apps using SAM. SAM simplifies the creation, management, and deployment of serverless applications. It makes constructing a serverless application easier by offering a single model to specify the application and automatically deploying the required resources.

## Install SAM CLI

**Mac**

Install SAM CLI using Brew
```
brew tap aws/tap
brew install aws-sam-cli
```
Requires Docker and the AWS CLI. [See installation instructions](https://docs.aws.amazon.com/serverless-application-model/latest/developerguide/serverless-sam-cli-install-mac.html)

**Linux**

Install SAM CLI by downloading a ZIP file

[aws-sam-cli-linux](https://github.com/aws/aws-sam-cli/releases/latest/download/aws-sam-cli-linux-x86_64.zip)

Requires Docker and the AWS CLI. [See installation instructions](https://docs.aws.amazon.com/serverless-application-model/latest/developerguide/serverless-sam-cli-install-linux.html)

**Windows**

Install SAM CLI using an MSI

[64 bit](https://github.com/awslabs/aws-sam-cli/releases/latest/download/AWS_SAM_CLI_64_PY3.msi)

Requires Docker and the AWS CLI. [See installation instructions](https://docs.aws.amazon.com/serverless-application-model/latest/developerguide/serverless-sam-cli-install-windows.html)

**AWS CDK support (Preview)**

Use AWS SAM CLI to build and test applications defined using AWS CDK.

[Download](https://github.com/aws/aws-sam-cli/releases/tag/sam-cli-beta-cdk)

Requires Node Package Manager. [See installation instructions](https://docs.aws.amazon.com/cdk/latest/guide/getting_started.html#getting_started_install)

## Why You Should Use AWS Serverless Application Model (SAM)?

### Single Deployment Configuration

Use SAM to organize related components, communicate settings like as RAM and timeouts amongst resources, and deploy all linked resources as a single, versioned entity.

### Integration with Development Tools

SAM interfaces with an AWS serverless tool suite. Discover new apps in the AWS Serverless Application Repository, and then use the AWS Cloud9 IDE to author, test, and debug SAM-based serverless applications, as well as AWS CodeBuild, AWS CodeDeploy, and AWS CodePipeline to create a deployment pipeline. Try AWS CodeStar to get started with a pre-configured project structure, code repository, and CI/CD pipeline.

### Local Testing and Debugging

Step through and debug your code with SAM CLI. It provides a Lambda-like execution environment locally and aids in the detection of bugs.

### Built on AWS CloudFormation

AWS SAM is an extension of AWS CloudFormation, so you gain CloudFormation's dependable deployment features. You may also utilize CloudFormation in your SAM template to create resources and access the entire set of resources, intrinsic functions, and other template capabilities provided in AWS CloudFormation.

### Built-In Best Practices

Deploy your infrastructure as configuration to take advantage of best practices like code reviews. With only a few lines of SAM configuration, you can enable gradual deployments via AWS CodeDeploy and tracing using AWS X-Ray.

## Benefits of Serverless Architecture on AWS

### Lower Infrastructure Costs

Serverless design eliminates the requirement for infrastructure management and maintenance. You just pay for the resources you use, and AWS grows the resources automatically based on demand. This implies there are no upfront expenditures, no idle resources, and no infrastructure maintenance costs.

### Automatic Scalability

Scaling is automatic with serverless architecture. AWS scales resources dynamically based on demand, ensuring that you have enough capacity to meet traffic spikes without incurring downtime or degraded performance. This allows for simple handling of high traffic volumes while keeping expenses low.
 
### Reduced Overhead

The serverless architecture eliminates the requirement for server provisioning, scalability, and management. This reduces overhead costs, allowing developers to concentrate on developing apps and features rather than maintaining infrastructure.

## Building Serverless Applications with AWS SAM

### Creating a Serverless Application

The first step in developing a serverless app with SAM is to establish a new project using the 'sam init' command. You may use this command to select a pre-built serverless application template or to construct a new template depending on your requirements.

### Defining Resources with AWS SAM

After you've created a new project, use the 'sam.yaml' template file to define the resources for your serverless application. You may specify your AWS Lambda functions, Amazon API Gateway APIs, and Amazon DynamoDB tables in this file. This file may also be used to define the event sources for your Lambda functions.

### Configuring AWS SAM Templates

After you've established the resources for your serverless application, you can use the AWS SAM templates to describe the deployment parameters. You can specify the AWS region, stack name, and any other settings that are necessary.

## Designing Scalable Serverless Applications

### Choosing the Right AWS Services

When developing a scalable serverless application, it is critical to use the appropriate AWS services. AWS offers a variety of services that may be utilized to create scalable and dependable serverless applications. Amazon S3, for example, may be used to store static assets, but Amazon Kinesis can be used to handle real-time data.

### Handling State and Data Flows

Serverless apps can be either stateless or stateful. Although stateless apps are easy to scale and manage, they are not appropriate for applications that require permanent data storage. Amazon DynamoDB, which delivers seamless scalability and great performance, may be used for stateful applications.

### Optimizing Performance

Reduce cold-start times using AWS Lambda Provisioned Concurrency to improve the performance of your serverless application. You may also utilize caching services like Amazon CloudFront and Amazon ElastiCache to improve your application's response time. You may also utilize AWS Auto Scaling to automatically scale the resources during peak traffic periods.

## Deploying and Testing Serverless Applications with AWS SAM

Building serverless apps with AWS Serverless Application Model (SAM) enables for simple code deployment and testing without the burden of managing servers.

### Deploying AWS SAM Applications

Deploying your SAM application is as simple as typing one command into your console. The command 'aws cloudformation deploy' packages your code, uploads it to S3, and creates or updates the CloudFormation stack that describes your application's resources. AWS CodePipeline may also be used to automate the deployment process and assure consistent delivery.

### Testing AWS SAM Applications

SAM simplifies testing your serverless application by supporting both local and integration testing. Before deploying your functions to AWS, use SAM Local to test and debug them locally. You can also use AWS CodePipeline to automate your testing and confirm that your code works properly before deploying it to production.

### Continuous Integration and Deployment

You can quickly set up continuous integration and deployment for your SAM apps using AWS CodePipeline and AWS CodeBuild. Every time you contribute to your repository, CodePipeline will automatically build, test, and deploy your code changes, ensuring that you always have the most recent version of your application in production. 

## Monitoring and Debugging Serverless Applications on AWS

Monitoring and debugging your serverless application is crucial to ensuring that it runs as intended and that issues are resolved as fast as possible.

### Logging and Tracing

You can monitor and troubleshoot issues with your application using AWS CloudWatch Logs and AWS X-Ray. CloudWatch Logs offers thorough logs of your application's activities, whereas X-Ray assists you in tracing requests as they travel through your application and identifying performance bottlenecks.

### Debugging and Troubleshooting

SAM Local enables you to debug your serverless functions locally, providing you more visibility into the behavior of your application. You can also use CloudWatch Metrics to monitor the performance of your application and create alarms for critical metrics.

### Performance Monitoring

AWS CloudWatch Metrics can be used to monitor SAM applications, allowing you to observe important performance metrics like as memory utilization, invocation length, and error rates. You may use this information to improve the performance of your application and guarantee that it scales to meet demand.

## Securing Serverless Applications with AWS SAM

SAM provides a variety of security measures to help you safeguard your code and data while developing serverless apps.

### Securing AWS SAM Templates

You may use SAM to define policies that restrict only authorized users from creating or updating application resources. You may also use AWS Identity and Access Management (IAM) to manage access to the resources of your application.

### Securing Serverless Functions

AWS Key Management Service (KMS) may be used to encrypt and safeguard your data at rest and in transit. SAM also enables secure function-to-function communication using AWS PrivateLink, allowing you to link your services safely within a VPC.

### Access Control and Identity Management

You may manage access to your SAM application resources and restrict permissions at the granular level using IAM. AWS Cognito may also be used to authenticate and authorize people to access your application.

## Best Practices for Building Scalable Serverless Applications with AWS SAM

To create scalable serverless applications that can manage massive amounts of traffic and data, best practices for architecture and design must be followed.

### Optimizing Resource Utilization

You should utilize AWS auto-scaling to automatically modify the number of compute resources provided to your application based on demand to maximize resource consumption. You should also employ caching to decrease request overhead on your application.

### Designing for Resiliency and Fault Tolerance

Your application should be designed to gracefully manage failures and errors. You may accomplish this by utilizing AWS managed services such as Amazon S3 and DynamoDB. To achieve high availability, you should also build your application using a distributed, fault-tolerant architecture.

### Scaling Applications for Growth

As the number of users and data increases, your application should be designed to scale effectively. You may utilize AWS Lambda functions to scale your application, which can be quickly scaled up or down based on demand. You should also build your application using a microservices architecture to allow for autonomous scalability of various components.

## Conclusion

So basically, AWS Serverless Application Model (SAM) is really awesome for making serverless applications on AWS that can handle a lot of traffic. With AWS SAM, developers can make things easier for themselves by designing, deploying, testing, and monitoring their apps, all while taking advantage of the benefits of serverless architecture. Hopefully, this article gave you a good idea of what AWS SAM can do, whether you're starting from scratch or moving an existing app to the cloud. So yeah, it's definitely worth checking out!

## Frequently Asked Questions (FAQ)

**What is AWS Serverless Application Model (SAM)?**

AWS SAM is a framework for developing AWS serverless apps. It makes it easier to define the Amazon API Gateway APIs, AWS Lambda functions, and Amazon DynamoDB tables that your serverless application will require.

**What are the benefits of serverless architecture on AWS?**

AWS's serverless design provides cheaper infrastructure costs, automated scalability, and decreased overhead. Developers may concentrate on building code and delivering features rather than worrying about server maintenance and management because there is no infrastructure to handle.

**How can I deploy and test serverless applications with AWS SAM?**

AWS SAM allows you to deploy and test serverless apps through the AWS Command Line Interface (CLI) or the AWS Management Console. AWS SAM has a local testing option that lets you test your serverless operations before deploying them to the cloud.

**What are the best practices for building scalable serverless applications with AWS SAM?**

Optimizing resource consumption, planning for robustness and fault tolerance, and scaling applications for growth are all best practices for creating scalable serverless applications with AWS SAM. Other best practices include selecting the appropriate AWS services for your application, effectively handling state and data flows, and maximizing performance.

**How does AWS SAM work?**

AWS SAM allows you to express functions, APIs, databases, and event source mappings using shorthand syntax. SAM translates and expands SAM syntax into AWS CloudFormation syntax during deployment. CloudFormation then provides your resources with dependable deployment capabilities.

**Is AWS SAM open-source?**

The Apache 2.0 license is used to open-source AWS SAM and the SAM CLI.

**How much does AWS SAM cost to use?**

There are no additional fees for using AWS SAM. You pay for AWS resources produced with SAM in the same way that you would if you built them manually. You just pay for what you use and only when you use it. There are no minimum costs or upfront commitments necessary.

**Which languages does AWS SAM support?**

AWS SAM may be used to create serverless apps that leverage any runtime supported by AWS Lambda. SAM CLI may also be used to debug Lambda functions built in Node.js, Java, Python, and Go locally.

**Which AWS regions support AWS SAM?**

AWS SAM is accessible in all locations that have AWS Lambda.

**What is AWS SAM CLI?**

The SAM Command Line Interface (CLI) allows you to develop, test, and debug serverless applications specified by AWS SAM templates on your local machine. SAM CLI provides a Lambda-like execution environment locally and assists you in detecting difficulties early on.

**How do I install AWS SAM CLI?**

Using pip, you can install AWS SAM CLI on Linux, Mac, or Windows.

**What is a SAM template?**

A SAM template file is a YAML configuration that specifies a serverless application's architecture. The template is used to declare all of the AWS resources that make up your serverless application in one location. Because AWS SAM templates are an extension of AWS CloudFormation templates, you can declare any resource in an AWS CloudFormation template in an AWS SAM template.

**How do I get started with AWS SAM?**

Install the AWS SAM CLI and use the ‘sam init’ command to produce a pre-configured AWS SAM template with example application code to get started with SAM. 

**What can I do with AWS SAM CLI?**

The AWS SAM CLI is a command-line interface that facilitates the development of SAM-based applications. You may use the AWS SAM CLI to launch Lambda functions locally, generate a deployment package for your serverless application, and publish it to the AWS Cloud.
SAM CLI provides a wide range of commands to meet your requirements. The ‘sam init’ command generates AWS SAM templates that include pre-written application code in the language of your choice. The sam local command emulates the Lambda execution environment and allows you to run Lambda functions and SAM-based serverless applications locally. It also allows you to produce local payloads, test your APIs via a local endpoint, and automate Lambda function testing. The sam package and sam deploy commands combine your application code and dependencies to create a "deployment package" that can be deployed to the AWS Cloud. Finally, the 'sam logs' command allows you to see, monitor, and filter Lambda function logs.

Thank you for reading!
Soumyadeep Mandal @imsampro