To change the heap size of Elasticsearch, set the
ES_JAVA_OPTS environment variable in the
podTemplate. It is also highly recommended to set the resource
limits at the same time to ensure that the pod gets enough resources allocated within the Kubernetes cluster. See Set compute resources for Elasticsearch for an example and more information.
ES_JAVA_OPTS is not defined, the Elasticsearch default heap size of 1Gi will be in effect.