Configure JVM arameters

You can configure the JVM in the hazelcast container using the jvm field of the CRD.

Configure a JVM parameter

Operator supports the following JVM configuration options in the Hazelcast resource. For more information, see the API reference.

Field	Description
initialRAMPercentage	Initial heap size of the Hazelcast process as a percentage of the total memory of a container.
maxRAMPercentage	Maximum heap size for a JVM running with a large amount of memory.
minRAMPercentage	Maximum heap size for a JVM running with a small amount of memory.

Set arbitrary JVM arguments

You can provide a list of JVM arguments.

Example configuration

yaml

apiVersion: hazelcast.com/v1alpha1
kind: Hazelcast
metadata:
  name: hazelcast
spec:
  jvm:
    args:
      - "-XX:MaxGCPauseMillis=200"

Example configuration

The following Hazelcast custom resource creates a cluster that uses all three parameters.

Example configuration

yaml

apiVersion: hazelcast.com/v1alpha1
kind: Hazelcast
metadata:
  name: hazelcast
spec:
  jvm:
    memory:
      initialRAMPercentage: "10"
      maxRAMPercentage: "20"
      minRAMPercentage: "10"

Garbage collector parameters

Enable logging

To enable garbage collector logging, you can use the following configuration:

Example configuration

yaml

apiVersion: hazelcast.com/v1alpha1
kind: Hazelcast
metadata:
  name: hazelcast
spec:
  jvm:
    gc:
      logging: true

This sets the JVM argument -verbose:gc.

Set the garbage collector

warning

Before making garbage collector-related changes using Operator, read Garbage collector considerations to decide which garbage collector to use.

To set the garbage collector:

Example configuration

yaml

apiVersion: hazelcast.com/v1alpha1
kind: Hazelcast
metadata:
  name: hazelcast
spec:
  jvm:
    gc:
      collector: <collector>

<collector> can be replaced with the following options:

<collector>	JVM Equivalent
Serial	-XX:+UseSerialGC
Parallel	-XX:+UseParallelGC
G1	-XX:+UseG1GC

Enable IPv6 stack

You can use JVM arguments to enable IPv6 addressing in Hazelcast and set up a Hazelcast cluster on an IPv6-stack Kubernetes Cluster. The following example creates an IPv6 Hazelcast cluster:

IPv6 Example configuration

yaml

apiVersion: hazelcast.com/v1alpha1
kind: Hazelcast
metadata:
  name: hazelcast-ipv6
spec:
  properties:
    - "hazelcast.prefer.ipv4.stack": "false"
  jvm:
    args:
      - "-Djava.net.preferIPv4Stack=false"
      - "-Djava.net.preferIPv6Addresses=true"