Is circuit breaker config help to control Memory usage

Is circuit breaker configuration help to control the Memory usage? By default it is 95% but I noticed that the memory reach to 99% in some of the nodes.

Is there any other way to control the memory usage via configuration?

Thanks

There's a difference between circuit breaker, RAM and JVM HEAP.
AFAIK the circuit breaker is here to avoid you shooting in your foot.

If a request is going to consume too much heap, the circuit breaker will reject the request.

But in general, Elasticsearch and Lucene is trying to use as much RAM as possible (outside of the HEAP size). And this is mostly done by the file system cache on an OS level.

Having a high usage of the RAM is "normal" then.

Not sure if I answered your question though.

Thanks for response. Memory usage means JVM HEAP usage here. I mostly face JVM HEAP spike and node unresponsive. so, is circuit breaker helps here? or is there any way to set JVM HEAP usage max threshold to 90% in any situation.

What is the output of:

GET /
GET /_cat/nodes?v
GET /_cat/health?v
GET /_cat/indices?v

If some outputs are too big, please share them on gist.github.com and link them here.