Vergangene Veranstaltung

eJUG Seminar - LocalStack/Testcontainers & CRaC-Superfast JVM

Anca Ghenade from LocalStack will present "Cloud Integration Testing Made Easy with LocalStack and Testcontainers" and Gerrit Grunwald from Azul Systems present "What the CRaC - Superfast JVM startup".

::Cloud Integration Testing Made Easy with LocalStack and Testcontainers::
Anca Ghenade

Integration testing is complicated as it is, even more so when third-party services are involved, but cloud-native AWS applications that rely on managed services are especially tough to test.

Cloud integration tests are particularly challenging due to the high complexity of the interconnected services, dependency management, deployment and provisioning intricacies, and potentially high costs. So how can we bring the ease and speed of unit tests into these integration tests? Ideally, we’d like to use a local setup where we can quickly spin up and deploy our services in an emulated environment that’s as close as possible to the real deal. By simulating real-world scenarios and testing the integration of various parts of the system, these tests help us identify and resolve issues early in the development process. This is where Testcontainers and LocalStack work beautifully together to bring you the best of integration tests and cloud services on your machine. We’ll explore how we can enhance the testability of a Spring Boot application that relies on AWS services and vastly increase the test coverage of our applications without any need for mocking or remote AWS sandbox accounts.

Testing your AWS-powered Spring Boot app with LocalStack and Testcontainers conveys isolation, speed, cost, and flexibility, making it effortless to get started with writing integration tests for your cloud application.

::What the CRaC - Superfast JVM startup::
Gerrit Grunwald

In a world where microservices are more and more a standard architecture for Java based applications running in the cloud, the JVM warmup time can become a limitation. Especially when you look at spinning up new instances of an app as response to changes in load, the warmup time can be a problem. Native images are one solution to solve these problems because their statically ahead of time compiled code simply doesn’t have to warmup and so has short startup time. But even with the shorter startup time and smaller footprint it doesn’t come without a drawback. The overall performance might be slower because of the missing JIT optimisations at runtime. There is a new OpenJDK project called CRaC (Coordinated Restore at Checkpoint) which goal it is to address the JVM warmup problem with a different approach. The idea is to take a snapshot of the running JVM, store it in files and restore the JVM at a later point in time (or even on another machine).
This session will give you a short overview of the CRaC project and shows some results from a proof of concept implementation.