Why does Elasticsearch Cluster JVM Memory Pressure keep increasing?
Got this answer from AWS Support
I checked the particular metric and can also see the JVM increasing from the last few days. However, I do not think this is an issue as JVM is expected to increase over time. Also, the garbage collection in ES runs once the JVM reaches 75% (currently its around 69%), after which you would see a drop in the JVM metric of your cluster. If JVM is being continuously > 75 % and not coming down after GC's is a problem and should be investigated.
The other thing which you mentioned about clearing the cache forfielddata for all indices was not helping in reducing JVM, that isbecause the dedicated master nodes do not hold any indices data andtheir related caches. Clearing caches should help in reducing JVM onthe data nodes.