I recently wrote an article on understanding WSO2 Carbon Architecture and how stuff works underneath. This article basically explains about how the server function at run-time with illustrations. Here is the summary and the contents covered in this article.
WSO2 Carbon is the base platform for all products of WSO2. By leveraging the OSGi technology, the WSO2 Carbon architecture is designed in such a way that it’s highly extensible, dynamic, and flexible. Over the years, the existing carbon platform was used to build a different set of products at WSO2 and helped to implement many solutions. The platform has gained maturity over time. There are new improvements, and features are added with each major release. The new family of products that are released now are based on Carbon version 4.0.0 and above. The 4.0.0 architecture undergone a major change than what is found in 3.2.0 based releases. The significant change is bringing Tomcat in to the OSGi environment, where in 3.2.0 based release, the tomcat was outside of OSGi environment and a bridging mechanism, called Servlet Bridge, was used to connect the outside world with OSGi environment.
This article covers the following in detail.
- The old architecture (pre 4.0.0)
- The new architecture
- How server starts
- How tomcat starts
- How requests get dispatched