Micro-Service Architecture With Eureka

 

Hey dev peeps! How is your life? I hope you all are doing good...Today I came with another interesting article. it's about Micro-Services! 

You may have already known about micro services. So, I'm not going to explain what it is. But I will go through a way to implement s clean architecture microservice setup with Eureka which is the platform provided by Netflix.

NOTE:

This article will only go through with the explanation of setup and in the upcoming articles, I will show how to implement this setup with a real-world example...

What is Eureka?

Eureka is an interjection used to celebrate a discovery or invention. It is a transliteration of an exclamation attributed to Ancient Greek mathematician and inventor Archimedes.

What is Netflix Eureka?

Netflix Eureka is a REST based middleware designed for the discovery and load balancing of web applications. So, with the use of Eureka, we can register our microservices(Eureka clients) into one place(Eureka server) and see them active or not. Actually, it's acting like a phone number directory!!

Architecture Setup

Let's look into the setup in a nutshell with a diagram. See the below image and let me explain then. 

Scenario:

Here I will take two microservices called employee service and department service. In this system, we have employees and each employee is assigned to a department. Both services are managing their own domain context. So, we have to build a bridge between two domains to collect data.

Is it complex to understand?? I hope it's not. Let's take the most important ones.

Request

This can be an API call that comes to one of the services. It can be one of the following examples.

• Fetch all employees
• Create an employee
• Fetch employees in a specific department
• Fetch all departments
• Fetch department details of an employee

Eureka Service Registry

This is the server known as Eureka Server: discovery server. So, both the microservices showed are connected to this server. When microservices are up and running, eureka will show them when we navigate to the eureka discovery endpoint from a web browser.

API Gateway

This is the middleman between API requests and Microservices. Any request that comes to any of the two microservices, will be going through this server first. We have to configure this server in a way to distinguish the microservices by endpoint pattern. In the diagram, I have made separate endpoint prefixes like "employees" and "departments". So, we should implement all the endpoints with these prefixes in the microservices.

Config Server

This has the responsibility to fetch common configurations for the services when services are up. We may have the same config setup section in each application.yml file, in the services registered to Eureka. So, we can put that config in a common place like GITHUB and fetch. Then microservices can talk to this config server and get the config from it. This reduces the work that needs to be done when the common configs are changing!

ELK Stack

Do you know what ELK means? That means ElasticSearch, Logstash, and Kibana! So, I have connected ELK to create a centralized logging setup for the microservices. Logs are very important to track service behaviors/anomalies in the real world. All these 3 should be installed locally to connect with the microservices. 

• ElasticSearch will let us create index patterns to store the log data.
• Logstash will let us configure services logs in a way to connect with ES.
• Kibana will let us see the logs in a kind of dashboard.

I think this is the most interesting part to learn in the setup...

Database

I will use mongo DB as the database connected to microservices. Here, two separate databases are connected following microservice fundamentals.

This is the simple explanation guys! Isn't it sound interesting? 

This is the tech stack including platforms/tools/libraries to be used in the upcoming implementation. Make sure you have downloaded and installed all the required software for this.

Tech Stack

• Service backend: Java - SpringBoot
• Database: MongoDB
• Logging: slf4j, ELK
• POJOs: Lombok
• API Testing: Postman
• Config: GIT

Thanks for coming here and read my article. If you are interested, you can give me feedback!

Until I come back, goodbye and stay safe!!!