# Find out what causes long GC cycles on client node **URL:** \ **Category:** Elasticsearch\ **Created:** [March 31, 2016, 10:27am UTC](https://discuss.elastic.co/t/find-out-what-causes-long-gc-cycles-on-client-node/45917 "2016-03-31T10:27:35Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![lwintergerst](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/lwintergerst/32/18164_2.png) [@lwintergerst](https://discuss.elastic.co/u/lwintergerst)\ **Post date:** [March 31, 2016, 10:27am UTC](https://discuss.elastic.co/t/find-out-what-causes-long-gc-cycles-on-client-node/45917/1 "2016-03-31T10:27:35Z")
Hi, my client nodes are experiencing very long GC cycles lately. Is there any way to narrow down the cause of this? We are using kibana most of the time, and usually dont query ES any other way. Our client nodes are running with 6GB Heap. They tend to toggle between 30% and 75% with, the occasional 80% usage. At some point, the heap usage rises until either an OOM or every long GCs kill the node. Besides the GCs, the logs don't show any other relevant information Luca ---
**Author:** ![unknownunknown](https://avatars.discourse-cdn.com/v4/letter/u/4da419/32.png) [@unknownunknown](https://discuss.elastic.co/u/unknownunknown)\ **Post date:** [March 31, 2016, 4:43pm UTC](https://discuss.elastic.co/t/find-out-what-causes-long-gc-cycles-on-client-node/45917/2 "2016-03-31T16:43:05Z")
This might be useful references: > **[Understanding the Memory Pressure Indicator | Elastic](https://www.elastic.co/blog/found-understanding-memory-pressure-indicator)** > > We all know memory is critical to Elasticsearch, but when should you add more? In the Found console we've included a memory pressure indicator so that you can easily check where your cluster is at in terms of memory usage and capacity. For those... > **[Top 10 Elasticsearch Metrics to Watch](https://sematext.com/blog/top-10-elasticsearch-metrics-to-watch/)** > > Last updated on Jan 16, 2018. Elasticsearch is booming.  Together with Logstash, a tool for collecting and processing logs, and Kibana, a tool for searching and visualizing data in Elasticsearch (aka… For me, it was almost always fielddata. Look for evictions in that and filterdata. \_node/stats and/or marvel or other monitor is your friend for troubleshooting this. If you are not using doc\_values, it can help (at some indexing cost). ---
**Author:** ![warkolm](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/warkolm/32/39224_2.png) [@warkolm](https://discuss.elastic.co/u/warkolm)\ **Post date:** [April 1, 2016, 5:09am UTC](https://discuss.elastic.co/t/find-out-what-causes-long-gc-cycles-on-client-node/45917/3 "2016-04-01T05:09:00Z")
> [@lwintergerst](#): > > Our client nodes are running with 6GB Heap. 6GB of how much in total? You can easily increase heap for dedicated client nodes to 75% of total system memory as you don't need to worry about FS caching. Otherwise the only reason clients will hit lots of GC is because you are doing more/larger queries through them. ---
**Author:** ![lwintergerst](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/lwintergerst/32/18164_2.png) [@lwintergerst](https://discuss.elastic.co/u/lwintergerst)\ **Post date:** [April 1, 2016, 5:26pm UTC](https://discuss.elastic.co/t/find-out-what-causes-long-gc-cycles-on-client-node/45917/4 "2016-04-01T17:26:03Z")
We have our client node running in parallel to one of our data nodes. Server: 64GB Data: 30GB Client: 6GB We are still on 1.7, therefore heap is more important than filesystem cache. I'm aware that this setup is far from perfect, but we have to work with a fixed budget. Luca ---
**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\ **Post date:** [July 5, 2017, 11:03pm UTC](https://discuss.elastic.co/t/find-out-what-causes-long-gc-cycles-on-client-node/45917/5 "2017-07-05T23:03:09Z")