In this beginners Microservices tutorial, you will learn-

What are Microservices? What is Monolithic Architecture?
What is Microservice Architecture?
Microservices VS. Monolithic Architecture
Microservice Challenges
SOA vs. Microservices
Microservices Tools
Best Practices of Microservices Architecture

What is Monolithic Architecture?

In layman terms, you can say that Monolithic architecture is like a big container in which all the software components of an application are clubbed into a single package. Let’s discuss an example of an eCommerce store in context of a Monolithic architecture.

In any e-commerce application, there are some standard features like Search, Review & Ratings, and Payments. These features are accessible to customers using their browser or apps. When the developer of the eCommerce site deploys the application, it is a single Monolithic unit. The code for different features like Search, Review & Ratings, and Payments are on the same server. To scale the application, you need to run multiple instances(servers) of these applications.

Let’s take an example of e-commerce application developed with microservice architecture. In this Microservices architecture example, each microservice is focused on single business capability. Search, Rating & Review and Payment each have their instance (server) and communicate with each other. In the Monolithic Architecture, all the components coalesce into a single module. But, in Microservices Architecture they are spread into individual modules(microservice) which communicate with each other as shown in the Microservices example above. The communication between microservices is a stateless communication where each pair of request and response is independent. Hence, Microservices can communicate effortlessly. In the Microservice Architecture, the Data is federated. Each Microservice has its separate data store. Next in this Java Microservices tutorial, we will learn about the difference between Microservices and Monolithic architecture.

Microservices vs. Monolithic Architecture

Microservice Challenges

MicroServices rely on each other, and they will have to communicate with each other. Compared to monolithic systems, there are more services to monitor which are developed using different programming languages. As it is a distributed system, it is an inherently complex model. Different services will have its separate mechanism, resulting in a large amount of memory for an unstructured data. Effective management and teamwork required to prevent cascading issues Reproducing a problem will be a difficult task when it’s gone in one version, and comes back in the latest version. Independent Deployment is complicated with Microservices. Microservice architecture brings plenty of operations overhead.

It is difficult to manage application when new services are added to the system A wide array of skilled professionals is required to support heterogeneously distributed microservices Microservice is costly, as you need to maintain different server space for different business tasks.

SOA vs. Microservices

SOA services are maintained in the organization by a registry which acts as a directory listing. Applications need to look up the services in the registry and invoke the service. In another world, SOA is just like an orchestra where each artist is performing with his/her instrument while the music director gives instructions to all. On the other end, Microservices is a form of service-oriented architecture style wherein applications are built as a collection of different smaller services instead of one software or application. Microservices is just like a troupe where each dancer is independent and know what they need to do. So, if they miss some steps, they know how to get back on the correct sequence. Now in this Microservices architecture tutorial, let’s learn about the difference between SOA and Microservices. Here is a detailed comparison between SOA and Microservices

Microservices Tools

1) Wiremock: Testing Microservices

WireMock is a flexible library for stubbing and mocking web services. It can configure the response returned by the HTTP API when it receives a specific request. It is also y used for testing Microservices. Download link: http://wiremock.org/

2) Docker

Docker is open source project that allows us to create, deploy, and run applications by using containers. By using these containers, developers can run an application as a single package. It allows you to ship libraries and other dependencies in one package. Download link: https://www.docker.com/

3) Hystrix

Hystrix is a fault tolerance java library. This tool is designed to separate points of access to remote services, systems, and 3rd-party libraries in a distributed environment like Microservices. It improves overall system by isolating the failing services and preventing the cascading effect of failures. Download Link: https://github.com/Netflix/Hystrix

Best Practices of Microservices Architecture

Separate data store for each Microservice Keep code of a similar level of maturity. Separate build for each Micro service. Always treat – severe as stateless.

Summary

Microservices is a service-oriented architecture pattern wherein applications are built as a collection of various smallest independent service units. Microservice Architecture is an architectural development style that allows building an application as a collection of small autonomous services developed for a business domain. Monolithic architecture is like a big container in which all the software components of an application are clubbed into a single package In a Microservice, every unit of the entire application should be the smallest, and it should be able to deliver one specific business goal In Monolithic architecture, large code base can slow down the entire development process. New releases can take months. Code maintenance is difficult Two types of Microservices are 1) Stateless 2) Stateful Microservices in Java rely on each other, and they will have to communicate with each other. Helps you to give emphasizes on a specific feature and business needs Service-oriented architecture shortly known as SOA is an evolution of distributed computing based on the request or reply design model for synchronous and asynchronous applications In SOA, software components are exposed to the outer world for usage in the form of services whereas Micro Service is a part of SOA. It is an implementation of SOA Wiremock, Docker, and Hystrix are some popular Microservices Tools