Java Microservices

What are Java Microservices?

Java microservices are independent components within a Java application that are each tasked with their own specialized function. Applications can be composed of many microservices, with each microservice contributing its own unique and critical component for achieving the application’s overall objectives.  

Microservices in applications are self-contained and designed to run independently. However, microservices still remain connected across the application. Microservices can communicate, sharing data and information across the application, while still maintaining autonomy when performing their individual functions.  

One way to think about microservices is to compare them to a beehive. Bees can protect the queen, collect pollen, or make honey. Each task is significant to the overall function of the hive. The bees can communicate information with one another, like important weather changes or incoming predators. However, the bees aren’t reliant on each other to perform their individual duties, so if one bee encounters an issue, the rest of the hive is unaffected.

What is the difference between a microservice architecture and a monolithic architecture for an application?

Applications have an architecture, which is the internal organization of the application’s components. The architectures most often considered for Java applications are Java microservice architectures and monolithic architectures. As explained above, in a microservice architecture, each task in an application is run independently of one another but maintains some connection. Alternatively, in a monolithic architecture, services are no longer self-contained, so each service has dependencies on both the application and the other services to run. Microservice architectures have several advantages over monolithic architectures, which are showcased in the increased resilience, innovation, and scalability.  

• Resilience. Microservice architectures are more resilient, as application components can be considered distinctively. In the microservice architecture, an individual service can undergo updates or repair, while not interfering with other services in the application. In other words, there is no single point of failure. In a monolithic architecture, the entire application must be shut down for a component to be updated or repaired, due to the dependencies between services. This means that a service error in a monolithic architecture will cause the entire application to shut down. It is hard for developers to identify the service that needs repair when the entire application is not functioning. With microservice architectures, an error will only shut down the microservice it’s located in, rather than the whole application, which is easier for developers to locate. 
• Innovation. Microservices also encourage developers to specialize. In monolithic architectures, services contain many dependencies, increasing the complexity of developing components. This requires a broad knowledge of how services interact and how they respond to different changes. In microservice architecture, this complexity is reduced, allowing developers to specialize in specific services. This ultimately promotes more innovation and encourages development. The reduced complexity also allows more teams of developers to work within the same application. The reduction of dependencies enables developers to focus on innovating their own services, without the fear of interfering with others.  
• Scalability. Microservices-based applications can be introduced to cloud environments and are better equipped for fluctuations in demand. Microservices are not required to run on the same server and can be accessed from different locations. This allows microservices to be maintained and developed on the cloud, scaling services without infrastructure limitations. Additionally, when an application is run, not every service is in use. This creates inefficiencies in a monolithic architecture, which must run the entire application, even if a service is not in use. Microservices can deploy the demanded feature, rather than deploying the entire application. New instances can be created in real time to address service demand, working to lower the cost and infrastructure required for running applications.  

How do microservices work in Java?

A microservices architecture can be used to enhance the performance of Java applications. These microservices are deployed in the Java Virtual Machine (JVM), which must work in cooperation with the microservices to maximize the benefits. To get the most out of microservices, a JVM must consistently perform at high levels, support multiple JVM instances on the same hardware, and reach high performance speeds quickly.  

JVM’s must perform consistently for a microservice architecture to be most effective, even with large workloads. As a part of its duties, the JVM employs the garbage collection feature to dispose of unused code. However, most garbage collectors on the market must pause the application to be deployed. This interferes with an application’s performance, as this function can take significant amounts of time to complete. Once completed, the application must warm up before services can be run again. Additionally, garbage collectors cannot pause an application at predicted intervals. When an application is unknowingly paused, it may be misidentified as an application error. These pauses may lead to false error reports, creating unnecessary performance issues when new instances are created as the response. 

A JVM also must efficiently allocate resources to optimize infrastructure resources. When multiple JVM’s are run on the same server, they can work together to properly distribute resources. Companies can lower their costs by enhancing their resource usage.  

Microservices are optimized when JVMs reach high-performance speeds quickly. When an application is started, the JVM must warm-up by profiling, analyzing and compiling information in the application. While the warm-up process occurs, traditional JVMs cannot run code until this process is completed. During this warmup time, performance is slowed as services become available and new instances are created. A faster warmup speed ensures applications and infrastructure reach their full potential faster, ultimately increasing the opportunity for services to optimize their value. 

How does Azul help with Java microservice environments?

Azul utilizes its 20 years of Java leadership to drive innovation for the Java community, helping companies achieve greater efficiency, higher performance and cost optimization. Azul Platform Prime, the world’s only cloud native JVM, offers numerous advantages over a traditional JVM for optimizing performance. Azul Platform Prime features a pauseless garbage collector and its own Ready-Now technology; the elimination of warm-up and pause times allow microservices to reach higher performances that can be sustained for longer. These innovations have set the standard in the Java community for high-performance JVM’s, creating new opportunities for Java in cloud computing.