Recently, I have been experimenting a lot over elastic search. During my research, I came to know ES heap usage as a key monitoring metric for ES operations. Some of the key divisions of heap include division into
- field data cache (can be monitored from _nodes/stats)
- filter cache (can be monitored from _nodes/stats)
Apart from these 2, which other buffer or caches usually takes up heap memory? I would like to know all of them, so that I can track down which cache/buffer was the culprit behind high heap usage.