I am facing a problem with my ES cluster, version 1.7.3
I have 10 nodes, each having 30g RAM.
Scatered around thos nodes are 2480 shards.
When I start the cluster, the heap usage skyrocket to 27-29g, with absolutely no cache being used. I'm not doing any indexing, nor do I search or aggregate on my data.
When I look at my nodes's stats, I can see that the old gen memory uses more than 28g.
If I start indexing, my cluster ends up collapsing due to increased time doing garbage collections that do not free any memory anyway.
I do not understand why I use so much memory.
Any insight would be greatly appreciated.
PS: please, be patient with my approximative english.