# Is it normal for client nodes in a cluster to have high OS memory usage?

**URL:** <https://discuss.elastic.co/t/is-it-normal-for-client-nodes-in-a-cluster-to-have-high-os-memory-usage/195251>\
**Category:** Elasticsearch\
**Created:** [August 14, 2019, 7:25pm UTC](https://discuss.elastic.co/t/is-it-normal-for-client-nodes-in-a-cluster-to-have-high-os-memory-usage/195251 "2019-08-14T19:25:13Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![John\_Doe1](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/john_doe1/32/46751_2.png) [@John\_Doe1](https://discuss.elastic.co/u/John_Doe1)\
**Post date:** [August 14, 2019, 7:25pm UTC](https://discuss.elastic.co/t/is-it-normal-for-client-nodes-in-a-cluster-to-have-high-os-memory-usage/195251/1 "2019-08-14T19:25:13Z")

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I have an elastic cluster with two client nodes. When I look at the /es/\_nodes/stats/os metric, I notice the used\_percent for each of them is around 95% even though elastic and java are the only thing running on the server. Is this expected?

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**Author:** ![William\_Brafford](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/william_brafford/32/51559_2.png) [@William\_Brafford](https://discuss.elastic.co/u/William_Brafford)\
**Post date:** [August 15, 2019, 7:33pm UTC](https://discuss.elastic.co/t/is-it-normal-for-client-nodes-in-a-cluster-to-have-high-os-memory-usage/195251/2 "2019-08-15T19:33:07Z")

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What version of Elasticsearch are you using? How much total memory is available for each machine, and what percentage of that have you allocated to Java?

You may want to consider Daniel's comment on this older forum topic: [Client node crash with OOM exception](https://discuss.elastic.co/t/client-node-crash-with-oom-exception/48626/2)

-William

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<div class="post-metadata">

**Author:** ![John\_Doe1](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/john_doe1/32/46751_2.png) [@John\_Doe1](https://discuss.elastic.co/u/John_Doe1)\
**Post date:** [August 15, 2019, 10:33pm UTC](https://discuss.elastic.co/t/is-it-normal-for-client-nodes-in-a-cluster-to-have-high-os-memory-usage/195251/3 "2019-08-15T22:33:04Z")

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I am on elastic 6.8. Here is the OS stats for the cluster, including total/used/free memory in bytes:  
[Elasticsearch OS Stats](https://pastebin.com/MbELXpTB)  
[Elasticsearch JVM stats](https://pastebin.com/35icx9HB)

According to the data above the client node has about 4GB, and the Java heap max is at 1GB/25% of the system memory.

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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:** [September 12, 2019, 10:33pm UTC](https://discuss.elastic.co/t/is-it-normal-for-client-nodes-in-a-cluster-to-have-high-os-memory-usage/195251/4 "2019-09-12T22:33:06Z")

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