How to limit a Java microservice by memory?

There are several ways to limit memory consumption of a Java microservice:

1. JVM parameters — set the maximum heap size and other memory parameters:

   • -Xmx — maximum heap size, for example -Xmx512m limits the heap to 512 MB.
   • -Xms — initial heap size.
   • -XX:MaxMetaspaceSize — limit metaspace.

2. Container or orchestrator level restrictions (e.g., Docker, Kubernetes):

   • In Docker, you can set a memory limit with --memory.
   • In Kubernetes — via resources.limits.memory.

3. Monitoring and profiling — to understand where and why the service consumes memory, and optimize the code.

Example of running a Java application with heap limit of 256 MB:

java -Xmx256m -jar app.jar

If the service runs in Docker, you can limit memory like this:

docker run --memory=512m my-java-service