By default, the JVM heap used by Elasticsearch has minimum and maximum size set to 1Gi. As the heap size should not exceed 50% of RAM size, ECK requests by default 2Gi of memory for the Elasticsearch Pod. To change the JVM heap size, use the
ES_JAVA_OPTS environment variable. It is also highly recommended to set the resource requests and limits to adjust the Pod memory to not exceed 50% of the RAM size. Both changes are shown below:
spec: nodes: - podTemplate: spec: containers: - name: elasticsearch env: - name: ES_JAVA_OPTS value: -Xms2g -Xmx2g resources: requests: memory: 4Gi limits: memory: 4Gi
For more information, see the Elasticsearch documentation on Setting the heap size.