# Slow garbage collection

**URL:** <https://discuss.elastic.co/t/slow-garbage-collection/52469>\
**Category:** Elasticsearch\
**Created:** [June 10, 2016, 6:22pm UTC](https://discuss.elastic.co/t/slow-garbage-collection/52469 "2016-06-10T18:22:37Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![esvetst](https://avatars.discourse-cdn.com/v4/letter/e/a183cd/32.png) [@esvetst](https://discuss.elastic.co/u/esvetst)\
**Post date:** [June 10, 2016, 6:22pm UTC](https://discuss.elastic.co/t/slow-garbage-collection/52469/1 "2016-06-10T18:22:37Z")

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Hi! Running 12 node Elasticsearch 2.2 cluster on Windows 2012, each node holds 10 shards (5 primary and 5 replica), shard size approx 15GB. I started experiencing slow garbage collection, like this:

[2016-06-10 07:46:50,250][WARN][monitor.jvm] [ESESSMW4061] [gc][young][1973921][15980] duration [18.2s], collections [1]/[18.4s], total [18.2s]/[1.2h], memory [9.4gb]-\>[6gb]/[15.4gb], all\_pools {[young] [4.1gb]-\>[36.3mb]/[4.2gb]}{[survivor] [45.6mb]-\>[546.1mb]/[546.1mb]}{[old] [5.2gb]-\>[5.4gb]/[10.6gb]}  
[2016-06-10 07:48:22,513][WARN][monitor.jvm] [ESESSMW4061] [gc][young][1973924][15981] duration [1.4m], collections [1]/[1.5m], total [1.4m]/[1.2h], memory [9.4gb]-\>[7.8gb]/[15.4gb], all\_pools {[young] [3.4gb]-\>[3.3mb]/[4.2gb]}{[survivor] [546.1mb]-\>[546.1mb]/[546.1mb]}{[old] [5.4gb]-\>[7.3gb]/[10.6gb]}  
[2016-06-10 07:48:52,614][WARN][monitor.jvm] [ESESSMW4061] [gc][young][1973937][15982] duration [17.8s], collections [1]/[18s], total [17.8s]/[1.2h], memory [12gb]-\>[8.5gb]/[15.4gb], all\_pools {[young] [4.1gb]-\>[25.5mb]/[4.2gb]}{[survivor] [546.1mb]-\>[546.1mb]/[546.1mb]}{[old] [7.3gb]-\>[8gb]/[10.6gb]}  
[2016-06-10 07:49:47,649][WARN][monitor.jvm] [ESESSMW4061] [gc][young][1973941][15983] duration [51.5s], collections [1]/[52s], total [51.5s]/[1.2h], memory [11.9gb]-\>[10.3gb]/[15.4gb], all\_pools {[young] [3.4gb]-\>[20.5mb]/[4.2gb]}{[survivor] [546.1mb]-\>[546.1mb]/[546.1mb]}{[old] [8gb]-\>[9.8gb]/[10.6gb]}  
[2016-06-10 07:54:05,394][WARN][monitor.jvm] [ESESSMW4061] [gc][old][1973947][12] duration [4.2m], collections [1]/[4.2m], total [4.2m]/[27.3m], memory [14.5gb]-\>[7gb]/[15.4gb], all\_pools {[young] [4.1gb]-\>[7.4mb]/[4.2gb]}{[survivor] [546.1mb]-\>[0b]/[546.1mb]}{[old] [9.8gb]-\>[7gb]/[10.6gb]}

The node then disconnects form the cluster and connects again after a while.

I suspect that this is due to slow at times CPU (these are virtual nodes, 8 core 2.6ghz intel Xeon, 32 GB RAM/16GB to Elastic). Is that making sense and generally what can I do to resolve this? Thanks for your suggestions!

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**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, 10:44pm UTC](https://discuss.elastic.co/t/slow-garbage-collection/52469/2 "2017-07-05T22:44:38Z")

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