For Java developers, the Just-In-Time (JIT) compiler is key to improved performance. However, in a container world, the performance gains are often negated due to CPU and memory consumption constraints. To help solve this issue, the Eclipse OpenJ9 JVM provides JITServer technology, which separates the JIT compiler from the application.

JITServer allows the user to employ much smaller containers enabling a higher density of applications, resulting in cost savings for end-users and/or cloud providers. Because the CPU and memory surges due to JIT compilation are eliminated, the user has a much easier task of provisioning resources for his/her application. Additional advantages include: faster ramp-up time, better control over resources devoted to compilation, increased reliability (JIT compiler bugs no longer crash the application) and amortization of compilation costs across many application instances.

We will dig into JITServer technology, showing the challenges of implementation, detailing its strengths and weaknesses and illustrating its performance characteristics. For the cloud audience we will show how it can be deployed in containers, demonstrate its advantages compared to a traditional JIT compilation technique and offer practical recommendations about when to use this technology.

Imagine a Java application that can start up in milliseconds, without compromising on throughput, memory, development-production parity or Java language features. Sounds out of this world, right? Well, through the use of technologies like CRIU support in Eclipse OpenJ9 and Liberty's InstantOn, we've taken one giant leap forwards for innovation within Java, offering exactly this! Join this session to learn more about these innovations and how you could utilise OSS technologies to deliver highly scalable and performant applications that are optimized for today's cloud-native environments.