# Cluster with routing enabled has one node with consistently high CPU usage

**URL:** <https://discuss.elastic.co/t/cluster-with-routing-enabled-has-one-node-with-consistently-high-cpu-usage/330796>\
**Category:** Elasticsearch\
**Created:** [April 26, 2023, 7:20am UTC](https://discuss.elastic.co/t/cluster-with-routing-enabled-has-one-node-with-consistently-high-cpu-usage/330796 "2023-04-26T07:20:06Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Chris\_Gatihi](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/chris_gatihi/32/25820_2.png) [@Chris\_Gatihi](https://discuss.elastic.co/u/Chris_Gatihi)\
**Post date:** [April 26, 2023, 7:20am UTC](https://discuss.elastic.co/t/cluster-with-routing-enabled-has-one-node-with-consistently-high-cpu-usage/330796/1 "2023-04-26T07:20:06Z")

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Hi,

We have an 8-node cluster with routing enabled and we're seeing consistently high CPU usage on one node in particular (over 90%). The other 7 nodes flash high at times but don't remain or do so as often.

Is this most likely a hotspot issue?

Also, just out of curiosity, does adaptive replica selection apply when routing is enabled? I know it's turned on by default but not sure if it is utilized in routing as in the default non-routing shard-allocation. So if, with routing enabled, I have P1 (P = primary) on the highly utilized node with R1 (R = replica) and R2 on a couple other less busy nodes, would P1 be generally avoided? My guess is that it would and that this could cause fluctuations in CPU usage across the 3 nodes?

Thanks,  
Chris

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**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:** [May 3, 2023, 1:04am UTC](https://discuss.elastic.co/t/cluster-with-routing-enabled-has-one-node-with-consistently-high-cpu-usage/330796/2 "2023-05-03T01:04:34Z")

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> [@Chris\_Gatihi](#):
>
> Is this most likely a hotspot issue?

Yep. Is the index getting a lot of index/query requests?

> [@Chris\_Gatihi](#):
>
> Also, just out of curiosity, does adaptive replica selection apply when routing is enabled?

Good question, let me see if I can find out.

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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:** [May 31, 2023, 1:05am UTC](https://discuss.elastic.co/t/cluster-with-routing-enabled-has-one-node-with-consistently-high-cpu-usage/330796/3 "2023-05-31T01:05:23Z")

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