coherence-operator

Tune JVM Runtime Settings

All production enterprise Java application must carefully tune the JVM settings for maximum performance. This sample shows how to set JVM arguments to Coherence running in Kubernetes.

Refer to Coherence Performance Tuning documentation for more information about JVM tuning.

There are many values in the values.yaml file of the Coherence Helm chart that sets JVM arguments to the JVM that runs Coherence within Kubernetes. The values are described in the following table:

--set Arguments	Descirption
store.maxHeap	Heap size arguments to the JVM. The format should be the same as that used for Java’s -Xms and -Xmx JVM options. If not set, the JVM defaults are used.
store.jmx.maxHeap	Heap size arguments passed to the MBean server JVM. Same format and meaning as the preceding row.
store.jvmArgs	Options passed directly to the JVM running Coherence within Kubernetes
store.javaOpts	Miscellaneous JVM options to pass to the Coherence store container

Return to Management samples / Return to samples

Prerequisites

Ensure you have already installed the Coherence Operator by using the instructions here.

Installation Steps

1. Install the Coherence cluster

   Install the cluster with the following settings:

   • --set store.maxHeap=1G - Set maxHeap to 1 GB

   • --set store.jvmArgs="-Xloggc:/tmp/gc-log -server -Xcomp" - Set generic options

   • --set store.javaOpts="-Dcoherence.log.level=6 -Djava.net.preferIPv4Stack=true - Set Coherence specific arguments

   $ helm install \
      --namespace sample-coherence-ns \
      --name storage \
      --set clusterSize=3 \
      --set cluster=coherence-cluster \
      --set imagePullSecrets=sample-coherence-secret \
      --set logCaptureEnabled=false \
      --set store.jvmArgs="-Xloggc:/tmp/gc-log -server -Xcomp"  \
      --set store.javaOpts="-Dcoherence.log.level=6 -Djava.net.preferIPv4Stack=true" \
      --set store.maxHeap=1g \
      coherence/coherence
   

2. Ensure the pods are running:

   $ kubectl get pods -n sample-coherence-ns
   

   NAME                                  READY   STATUS    RESTARTS   AGE
   coherence-operator-66f9bb7b75-hqk4l   1/1     Running   0          13m
   storage-coherence-0                   1/1     Running   0          3m
   storage-coherence-1                   1/1     Running   0          2m
   storage-coherence-2                   0/1     Running   0          44s
   

   The JVM arguments include the store. argument and other arguments required by the operator and Coherence.

   -Xmx1g -Xms1g -Xloggc:/tmp/gc-log -server -Xcomp -Xms8g -Xmx8g -Dcoherence.log.level=6 -Djava.net.preferIPv4Stack=true
   

3. Inspect the result

   To inspect the full JVM arguments, you can use kubectl logs storage-coherence-0 -n sample-coherence-ns > /tmp/storage-coherence-0.log and search for one of the arguments that you specified.

Uninstall the Charts

Use the following command to delete the chart installed in this sample:

$ helm delete storage --purge

Before starting another sample, ensure that all the pods are removed from previous sample.

If you want to remove the coherence-operator, then include it in the helm delete command.

This site is open source. Improve this page.