# Regarding Coordinator Node Memory Usage

**URL:** <https://discuss.elastic.co/t/regarding-coordinator-node-memory-usage/147339>\
**Category:** Elasticsearch\
**Created:** [September 5, 2018, 8:30am UTC](https://discuss.elastic.co/t/regarding-coordinator-node-memory-usage/147339 "2018-09-05T08:30:09Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![dawiro](https://avatars.discourse-cdn.com/v4/letter/d/71e660/32.png) [@dawiro](https://discuss.elastic.co/u/dawiro)\
**Post date:** [September 5, 2018, 8:30am UTC](https://discuss.elastic.co/t/regarding-coordinator-node-memory-usage/147339/1 "2018-09-05T08:30:09Z")

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Hi,  
I'm running at 5.6.3 and have two coordinator nodes running 5.5GB HEAP in 8GB of RAM. I've started to see them being oom-killed when elasticsearch is the only service running on these VMs.

Do coordinator nodes have much in the way of off-heap memory requirements? I'm trying to understand what is causing the service to be killed.

Regards,  
D

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**Author:** ![danielmitterdorfer](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/danielmitterdorfer/32/110510_2.png) [@danielmitterdorfer](https://discuss.elastic.co/u/danielmitterdorfer)\
**Post date:** [September 7, 2018, 3:36pm UTC](https://discuss.elastic.co/t/regarding-coordinator-node-memory-usage/147339/2 "2018-09-07T15:36:35Z")

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Hi,

depending on your system configuration that does not leave a whole lot of headroom. The OS reserves a certain amount of memory for itself and also the JVM has some overhead on top of what's reserved for the Java heap. You can see some of this overhead with [native memory tracking](https://docs.oracle.com/javase/10/vm/native-memory-tracking.htm#JSJVM-GUID-710CAEA1-7C6D-4D80-AB0C-B0958E329407) but be aware that this has some performance overhead so you should probably not turn this on in production without prior testing.

Finally, Elasticsearch uses off-heap memory for various purposes. The [node stats API](https://www.elastic.co/guide/en/elasticsearch/reference/current/cluster-nodes-stats.html) provides data on on-heap and off-heap memory usage.

Daniel

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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:** [October 5, 2018, 3:36pm UTC](https://discuss.elastic.co/t/regarding-coordinator-node-memory-usage/147339/3 "2018-10-05T15:36:50Z")

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