As the name suggests, Microservices are a composition of smaller independent services that can communicate over well-defined APIs. Microservices offer an organizational approach to the SDLC and are developed by small, self-contained teams. Its architecture makes it easier for applications to scale and enable innovation, produce and market faster with new features. Monolithic architectures have given way to microservices, leading the charge on experimentation and innovation.

In a monolithic architecture, the processes run as a single service, i.e., if one process experiences an increase in demand, the rest of the processes must also be scaled up. As the code base grows, adding or upgrading features becomes more complex and challenging. Therefore, experimentation and innovation become difficult. Monolithic architecture also comes with the risk of application availability as they are interdependent processes.  

On the other hand, the microservices architecture enables applications to be built with independent components, with each application process running as a service. They communicate using an interface with lightweight APIs. Microservices are built according to their business capabilities, with each service performing a single function. These independent units make it easy for each service to be scaled, updated and deployed in response to the demand for specific functions of the application.

Microservices on AWS - Application Scalability

Autonomy and specialization in microservices

The defining characteristics of microservices are their autonomy and specialization. For instance, each component in microservices architecture can be independently developed and deployed without impacting other features or their functionalities. They do not share their code with the other services and the only communication among individual components is via the APIs.

Moreover, each service is well-designed for specific capabilities and focuses on a particular issue. If the developers add more code to the service and add complexity, the service can be broken into smaller components. These characteristics enable faster product development, a seamless SDLC and rapid delivery.

Why is AWS best suited for microservices?

AWS has become the go-to solution to implement applications with the above benefits from microservices. AWS brings several services and solutions to support microservice applications in various categories.

Migrate to AWS

Microservice applications on AWS

  • Amazon ECS: Microservices are deployed as containers using the AWS serverless ecosystem, like AWS Lambda. It is done through the Amazon Elastic Container Service or the Elastic Kubernetes Service.
  • Networking: Amazon ECS service discovery and AWS App Mesh can be used to improve coordination and communication, with AWS Elastic Load Balancing for traffic routing and API Gateway for API management.
  • Storage: Microservices offer secure data storage through Amazon Simple Storage Service (S3) and ElastCache.
  • Databases: Relational database services come through the Amazon RDS or cloud-native databases like DynamoDB or Amazon Aurora.
  • CI/ CD workflows: AWS supports CI/ CD workflows with its Elastic Container Registry (ECR), AWS CodeCommit and AWS CloudFormation.
  • Monitoring: Microservices enable monitoring of the API traffic with AWS CloudTrail and the infrastructure with CloudWatch.
  • Messaging: Message queueing can be done through the Simple Queue Service (SQS) and Simple Notification Service (SNS) to send notifications.

Historically, applications were built with multiple layers: one UI layer, one business layer and one for data persistence. All functions and components were included in one segment. However, with microservices architecture, you can separate the software by individual functionality. Each component is self-sufficient, independent and performs a single function. The components are enabled by AWS’ building blocks.

Building blocks of AWS

AWS comes with building blocks to empower and sustain microservices development. They can be used with AWS Lambda to run serverless functions or AWS Fargate to run serverless Docker containers. Three AWS services can be used to implement straightforward microservices architecture:

  • AWS API Gateway:

    It can help create and run serverless RESTful APIs. It is the gateway for applications hosted by Amazon or on-premises or cloud, with enhanced security in the applications. 

  • Lambda functions:

    The API gateway and Lambda work hand-in-hand to respond to synchronous requests coming to the application, enabling serverless applications.

  • Lambda-based apps:

    AWS CloudFormation helps deploy and manage serverless applications. AWS SAM CLI further helps start and test AWS serverless runtime on local machines before moving it to production.

Advantages of microservices on AWS

The independent components offered by microservices on AWS are particularly beneficial for today’s fast-paced digital era. They offer agility and easy deployment with reusable code, scalability, and resilience.

1. Enterprise-wide agility

Microservices empower enterprises to create small independent teams that foster a culture of service ownership. These skilled teams work within a well-defined and understood context and quickly with autonomy, leading to shorter development times. Enterprises benefit from the aggregate throughout and put their products through the paces of a development cycle and delivery faster. With microservices being independent, changes to a service can be made without affecting the other services. Moreover, it makes it easy to experiment and innovate through continuous integration (CI) and continuous delivery (CD) pipelines. The cost of failure is limited to a service, making it easier to try out new ideas, update codes, and give the team time to add new features.

The well-defined modules also enable reusing code, for instance, if a service is written for a specific function, it can be reused as a building block for a new feature. Developers are freed from writing new code for each new feature.

2. Resilience and scalability

Microservices enable individual scalability of each different service in response to the supported application or its features. It allows working with the right size of infrastructure needed for the service while remaining available to meet increased demand for the service. While the cost of failure is low in independent services, there is also greater resistance to the loss. A single component may fail in microservices without affecting the entire application, unlike the monolithic architecture. Applications can handle the failure by degrading and fixing the failed functionality within the contained service

To conclude

The relevance of microservices cannot be overstated in today’s market for event-driven applications. AWS offers a complete platform for your microservices with distinct advantages such as integrated building blocks to support any architecture regardless of load, scale or complexity. While there is no one-size-fits-all solution in microservices, the advantage lies in having the autonomy to choose tools best suited for the specific functionality.  

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Subashini Suresh