Application Server

What is an Application Server?

An application server is a software platform that provides an environment for running and managing applications. It acts as an intermediary between end users/clients and the backend systems or databases. The primary purpose of an application server is to host, manage, and deliver applications to clients over a network.

An application server serves as middleware, enabling communication and integration between various components of an application, such as web servers, databases, and business logic.

What are some of the popular Application Servers?

Examples of popular application servers include Apache Tomcat, JBoss (WildFly), IBM WebSphere Application Server, Oracle WebLogic Server, and Microsoft Internet Information Services (IIS). These servers support different programming languages, frameworks, and application types, such as Java, ASP .NET, and PHP.

Why use an Application Server?

There are several reasons why application servers are used in modern application architectures:

  • Centralized application management: Application servers provide a centralized platform for managing and deploying applications. They have tools and interfaces to easily deploy, configure, and update applications, making it more efficient to manage a large number of applications across different environments.
  • Simplified development and deployment: Application servers support standardized frameworks and APIs, making it easier for developers to build and deploy applications. They provide built-in services and libraries that handle common tasks such as database connectivity, transaction management, and security, reducing the development effort and time-to-market.
  • Scalability and load balancing: Application servers are designed to handle concurrent requests and can scale applications horizontally by adding more server instances. They often include load balancing mechanisms to distribute incoming requests across multiple server nodes, ensuring optimal resource utilization and improved performance under high traffic conditions.
  • Middleware capabilities: Application servers act as middleware, enabling integration and communication between various components of an application.
  • Security and authentication: Application servers provide security features such as authentication, authorization, and data encryption. They can integrate with identity and access management systems, enabling centralized user authentication and authorization.
  • Performance optimization: Application servers offer performance optimization features like caching, connection pooling, and request/response optimization. These optimizations help improve the responsiveness and efficiency of the application, resulting in a better user experience.

Overall, using an application server simplifies development, improves application performance and scalability, enhances security, and provide centralized management and monitoring capabilities. This is why application servers are essential components in modern application deployments.

How do Application Servers work?

Application servers often host the middleware components of an application. A web server often receives and directs requests to an application server which then handles the business logic of the application. To be scalable, application servers implement multi-threading. Requests can execute in parallel using individual threads.

What is the difference between an Application Server and a Web Server?

While a web server serves static content (pages, files, images, videos, and the like) only, an application server serves dynamic content (implemented using JSPs, servlets, etc). Many application servers also support similar capabilities as web servers (HTTP processing, caching of static content, etc.) and this makes the distinction with web servers less apparent.

How are Application Servers monitored?

Since application servers are important components of a web application architecture, it is essential that they be monitored. All key components of application servers must be monitored. The runtime engine – Java, .NET, etc. – must also be monitored. Workloads to the different application server components and their responsiveness must be tracked. Unfortunately, there is no standard mechanism for monitoring different application servers. Even when they support the same protocol – e.g., Java Management Extensions – the attributes to be monitored vary from one application server to another.

Monitoring tools like eG Enterprise embed built-in monitoring capabilities for popular application servers like Apache Tomcat, JBoss, Oracle WebLogic, IBM WebSphere and so on.