Docker & Java

This repo contains demo materials for:

• Tips minimize java containers images
• Tricks for fast startup java apps running in containrs
• gotchas and issues while running java apps in containers and the improvements that has been made

The repo is splitte into multiple branchs, each contains a specific topic. The Dockerfiles uses the generated jar after running the build (mvn clean package). The build step could be integrated in the provided Dockerfiles, but it would slow the demoing the intetntion of this repo, so I kept it outside. Below branch details:

• master: simple netty app, running in a container
• cdc: This showcase the class data sharing (CDS) feature. CDC offers dynamic sharing of data between multiple Java Virtual Machines (JVM), which helps to reduce the startup time and memory footprint.
• aot: Using Ahead Of Time compilation. It compiles the bytecode such that it is completely static which should lead to the fastest startup and initial execution speed.
• graal: This part uses graal VM to create native images for existing JVM-based applications.
• sb: This branch contains a simple instructions to run the petclinic application and test how it behaves running inside a java 8 docker container, and java 11!