JJ_Mind :
After learning about arguments that can be passed to a Java 8 Virtual Machine to make it container-aware (i.e. -XX:+UnlockExperimentalVMOptions -XX:+UseCGroupMemoryLimitForHeap), I am trying to add these arguments to my Kubernetes deployment for a Spring Boot service.
In containers section of my deployment YAML file, I have the following:
resources:
requests:
memory: "256Mi"
cpu: "50m"
limits:
memory: "512Mi"
cpu: "200m"
env:
- name: JVM_OPTS
value: "-Xms256M -XX:+UnlockExperimentalVMOptions -XX:+UseCGroupMemoryLimitForHeap -XX:MaxRAMFraction=1"
In my Dockerfile, I have:
ENV JVM_OPTS="-Xmx256M"
ENV JVM_ARGS="-Dspring.profiles.active=kubernetes"
EXPOSE 8080
ENTRYPOINT [ "sh", "-c", "java $JVM_ARGS $JVM_OPTS -jar testservice.jar" ]
I can't seem to figure out why the max heap sized does not get sized properly:
$ kubectl exec test-service-deployment-79c9d4bd54-trxgj -c test-service -- java -XshowSettings:vm -version'
VM settings:
Max. Heap Size (Estimated): 875.00M
Ergonomics Machine Class: server
Using VM: OpenJDK 64-Bit Server VM
openjdk version "1.8.0_171"
OpenJDK Runtime Environment (IcedTea 3.8.0) (Alpine 8.171.11-r0)
OpenJDK 64-Bit Server VM (build 25.171-b11, mixed mode)
What am I doing wrong here?
On a local Docker install, I can see the JVM max heap set correctly:
$ docker run openjdk:8-jre-alpine java -Xms256M -Xmx512M -XX:+UnlockExperimentalVMOptions -XX:+UseCGroupMemoryLimitForHeap -XX:MaxRAMFraction=1 -XshowSettings:vm -version
VM settings:
Min. Heap Size: 256.00M
Max. Heap Size: 512.00M
Ergonomics Machine Class: server
Using VM: OpenJDK 64-Bit Server VM
openjdk version "1.8.0_171"
OpenJDK Runtime Environment (IcedTea 3.8.0) (Alpine 8.171.11-r0)
OpenJDK 64-Bit Server VM (build 25.171-b11, mixed mode)
silverfox :
When running java -XshowSettings:vm -version in container, JVM_OPTS is not include in your command.
Try with this one
kubectl exec test-service-deployment-79c9d4bd54-trxgj -c test-service \
-- sh -c 'java $JVM_OPTS -XshowSettings:vm -version'