In the past, application servers were essential for running Java applications. They provided a number of features that were necessary for complex applications, such as:

• Dependency management
• Transaction management
• Security
• Caching
• Messaging

However, with the rise of microservices, many developers are moving away from application servers.

As a result, many developers believe that application servers are no longer necessary for microservices. However, there are still a number of reasons why application servers can be beneficial for Java applications, even in a microservices architecture.

Benefits of not using an application server

To configure and run one application server for each service can lead to a complex configuration and maintenance task. By using an embedded server we benefit from:

• Faster deployment.
• Easier continuous integration tasks.
• Minimum maintenance effort.

But can we use Application Servers for serving and managing Microservices? Indeed we can!

Benefits of Application Servers for Microservices

Centralized configuration: Application servers provide a centralized configuration for all of your microservices. This can make it easier to manage your applications and ensure that they are all configured correctly.

Service discovery: Application servers can provide service discovery for your microservices. This means that microservices can find each other without having to know each other’s addresses.

Load balancing: Application servers can load balance your microservices. This can help to improve the performance of your applications by distributing traffic evenly across all of your microservices.

Health monitoring: Application servers can monitor the health of your microservices. This can help you to identify and fix problems before they impact your users.

In addition to the benefits mentioned above, application servers can also provide a number of other features that can be helpful for Java applications, such as:

Security: Application servers can provide a number of security features, such as authentication, authorization, and encryption.

Performance: Application servers can be optimized for performance, which can help to improve the speed and responsiveness of your applications.

Scalability: Application servers can be scaled horizontally to support more users and traffic.

Reliability: Application servers can be made highly available to ensure that your applications are always up and running.

If you are looking for a robust and scalable platform for running your Java applications, then an application server is a good option to consider.

The History of Application Servers

The first application servers were developed in the early 1990s. They were designed to provide a platform for running Java applications in a distributed environment. The first application servers were monolithic, meaning that they were all-in-one solutions that provided a wide range of features.

As Java applications became more complex, the need for specialized application servers arose. For example, some application servers focused on performance, while others focused on security. In the early 2000s, the Java EE platform was standardized, which led to the development of a number of open source application servers.

The Rise of Microservices

Microservices are a relatively new architectural style for developing software applications. In a microservices architecture, an application is broken down into a number of small, independent services. Each service is responsible for a specific task, and the services communicate with each other over a network.

Microservices have a number of advantages over traditional monolithic applications. They are more scalable, flexible, and agile. They are also easier to develop and maintain.

The rise of microservices has led to a decline in the use of traditional application servers. Many developers believe that microservices do not need an application server, as each service can be deployed and managed independently.

Conclusion

So, are application servers dead? Not quite!

While they are not as widely used as they once were, they still have a number of advantages that make them a good choice for certain types of applications. They can provide a number of benefits that can make it easier to develop, deploy, and manage your Java applications. If you are considering moving to a microservices architecture, you should carefully consider whether or not an application server is right for you.

Alexius Dionysius Diakogiannis

Passionate Archer, Runner, Linux lover and JAVA Geek! That's about everything! Alexius Dionysius Diakogiannis is a Senior Java Solutions Architect and Squad Lead at the European Investment Bank. He has over 20 years of experience in Java/JEE development, with a strong focus on enterprise architecture, security and performance optimization. He is proficient in a wide range of technologies, including Spring, Hibernate and JakartaEE. Alexius is a certified Scrum Master and is passionate about agile development. He is also an experienced trainer and speaker, and has given presentations at a number of conferences and meetups. In his current role, Alexius is responsible for leading a team of developers in the development of mission-critical applications. He is also responsible for designing and implementing the architecture for these applications, focusing on performance optimization and security.