Maybe it's the field cache that moves to old gen, when using facets. I am tackling this challenge by a combination of several strategies
- tuning index.indices.fielddata.cache.size - working around the issue by increasing node transport and ping timeout from 5s to something high like 30s (so GCs are allowed to run 20s without node disconnects) - reducing number of shards per node (this just means to reduce the number of docs / index size / filter cache per node somehow), simplest method is adding nodes - using heap sizes as small as possible - in my use case 6G are sufficient - not sure if you want to go the path on the bleeding edge, but using Java 8 and G1GC with XX:MaxGCPauseMillis of ~100-1000ms helps me. CPU load is a bit higher with G1GC, but since I have 32 cores on a node, it does not matter that much. - otherwise, there are lots of CMS GC tuning options (needs deep GC analysis) Jörg On Mon, Feb 17, 2014 at 4:34 PM, Nic Long <[email protected]>wrote: > Hey all, > > we regularly (several times a week) get longish GCs (20s or more) due to > promotion failures. > > From what I understand this type of major GC is caused by fragmentation of > the heap. > > So I'm wondering: > > 1. What is all the stuff ES puts into the heap that ends up in the Old Gen? > 2. Are there any recommended strategies for dealing with this specific > kind of problem. > > For example, would allowing more filter caching help or cause even more > problems? And so on. > > To give a little more info on our usage, we're read heavy, nearly entirely > filter operations. Our heap is at ~10g. nearly all of which is used by the > Old Gen (until a major GC runs). > > -- > You received this message because you are subscribed to the Google Groups > "elasticsearch" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/elasticsearch/4b3ef926-94b7-4de0-b076-d5fdbc44021c%40googlegroups.com > . > For more options, visit https://groups.google.com/groups/opt_out. > -- You received this message because you are subscribed to the Google Groups "elasticsearch" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/elasticsearch/CAKdsXoG7nX7YRy7dEnfDToWaPXvVTjfwP%3DXYdPzjRk91YJ0d%2BA%40mail.gmail.com. For more options, visit https://groups.google.com/groups/opt_out.
