How Microservices Performed in Java
Microservices have become hugely popular in recent years. Mainly, because they come with a couple of benefits that are super useful in the era of containerization and cloud computing. You can develop and deploy each microservice on a different platform, using different programming languages and developer tools.
Here some priciple microservices follows:
- Standardized service contract (services follow a standardized description)
- Loose coupling (minimal dependencies)
- Service abstraction (services hide their internal logic)
- Service reusability (service structure is planned according to the DRY principle)
- Service autonomy (services internally control their own logic)
- Service statelessness (services don’t persist state from former requests)
- Service discoverability (services come with discoverable metadata and/or a service registry)
- Service composability (services can be used together)
Pros of microservices
Microservices have become hugely popular in recent years. Mainly, because they come with a couple of benefits that are super useful in the era of containerization and cloud computing. You can develop and deploy each microservice on a different platform, using different programming languages and developer tools. Microservices use APIs and communication protocols to interact with each other, but they don’t rely on each other otherwise.
The biggest pro of microservices architecture is that teams can develop, maintain, and deploy each microservice independently. This kind of single-responsibility leads to other benefits as well. Applications composed of microservices scale better, as you can scale them separately, whenever it’s necessary. Microservices also reduce the time to market and speed up your CI/CD pipeline. This means more agility, too. Besides, isolated services have a better failure tolerance. It’s easier to maintain and debug a lightweight microservice than a complex application, after all.
Cons of microservices
As microservices heavily rely on messaging, they can face certain problems. Communication can be hard without using automation and advanced methodologies such as Agile. You need to introduce DevOps tools such as CI/CD servers, configuration management platforms, and APM tools to manage the network. This is great for companies who already use these methods. However, the adoption of these extra requirements can be a challenge for smaller companies.
Having to maintain a network lead to other kinds of issues, too. What we gain on the simplicity of single-responsibility microservices, lose on the complexity of the network. Or, at least a part of it. For instance, while independent microservices have better fault tolerance than monolithic applications, the network has worse.
Communication between microservices can mean poorer performance, as sending messages back and forth comes with a certain overhead. And, while teams can choose which programming language and platform they want to use, they also need to collaborate much better. After all, they need to manage the whole lifecycle of the microservice, from start to end.
Microservices in Java
Java is one of the best languages to develop microservices. There are a couple of microservice frameworks for the Java platform you can use, such as:
- Dropwizard
- JHipster
- Spark framework
- Spring framework
- Swagger
- Play framework
- Vert.x
Using Spring Boot is the most popular way to build microservices in Java. Spring Boot is a utility built on top of the Spring platform. It makes it possible to set up stand-alone Spring apps with minimal configuration. It can save a lot of time by automatically configuring Spring and third-party libraries.
For instance, here’s a very simple microservices example by Paul Chapman, published in detail in the official Spring blog. It uses Spring, Spring Boot, and Spring Cloud to build the application. I won’t include code examples here, as you can find them in the original article. We’ll only briefly take a look at the application structure. The steps are as follows:
Create the service registration (so that microservices can find each other), using the Eureka registration server (incorporated in Spring Cloud)
Create an account management microservice called “Account Service” with Spring Boot
Create a web service to access the microservice, using Spring’s RestTemplate class
Microservices are the most suitable for large-scale applications. Smaller apps are usually better off with a monolithic code base, though.
While it’s easier to develop and maintain independent microservices, network management requires additional efforts. Container platforms, DevOps practices, and cloud computing can help a lot in adopting the microservices architecture.
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