After upgrading to Elasticsearch 7.8.1 from 7.6.1, the CPU usage is reaching 100% most of the time on all 4 nodes. We didn't have this issue before the upgrade.
The GC is almost 0% after the upgrade. It was noticed that the java version has been upgraded to 14. But the jvm.options file is having the config for the previous version. We are yet to apply these changes and would like to know if this GC and high CPU usage are related to this configuration.
Screenshots of Kibana metrics:
GC logging is not enabled, so couldn't get it.
JVM config for java 14 (not applied yet):