# Master ES Node pegged at 100% CPU Utilization

**URL:** <https://discuss.elastic.co/t/master-es-node-pegged-at-100-cpu-utilization/53711>\
**Category:** Elasticsearch\
**Created:** [June 22, 2016, 9:17pm UTC](https://discuss.elastic.co/t/master-es-node-pegged-at-100-cpu-utilization/53711 "2016-06-22T21:17:51Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![echerno21](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/echerno21/32/5099_2.png) [@echerno21](https://discuss.elastic.co/u/echerno21)\
**Post date:** [June 22, 2016, 9:17pm UTC](https://discuss.elastic.co/t/master-es-node-pegged-at-100-cpu-utilization/53711/1 "2016-06-22T21:17:51Z")

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The Master Es Node is pegged at 100% CPU Utilization after adding some new logs for ingestion. Below is a sample of hot threads:

> 95.3% (476.2ms out of 500ms) cpu usage by thread 'elasticsearch[ip-xx-xx-xx-xxx][clusterService#updateTask][T#1]'  
> 6/10 snapshots sharing following 33 elements  
> java.util.zip.Deflater.deflateBytes(Native Method)  
> java.util.zip.Deflater.deflate(Deflater.java:430)  
> java.util.zip.Deflater.deflate(Deflater.java:352)  
> java.util.zip.DeflaterOutputStream.deflate(DeflaterOutputStream.java:251)  
> java.util.zip.DeflaterOutputStream.write(DeflaterOutputStream.java:211)  
> java.io.BufferedOutputStream.write(BufferedOutputStream.java:122)  
> org.elasticsearch.common.io.stream.OutputStreamStreamOutput.writeBytes(OutputStreamStreamOutput.java:42)  
> org.elasticsearch.common.io.stream.StreamOutput.write(StreamOutput.java:299)  
> java.util.zip.CheckedOutputStream.write(CheckedOutputStream.java:73)  
> com.fasterxml.jackson.core.json.UTF8JsonGenerator.\_flushBuffer(UTF8JsonGenerator.java:2003)  
> com.fasterxml.jackson.core.json.UTF8JsonGenerator.\_writeStringSegments(UTF8JsonGenerator.java:1148)  
> com.fasterxml.jackson.core.json.UTF8JsonGenerator.writeFieldName(UTF8JsonGenerator.java:204)

Any ideas on why this might be happening?

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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, 10:41pm UTC](https://discuss.elastic.co/t/master-es-node-pegged-at-100-cpu-utilization/53711/2 "2017-07-05T22:41:18Z")

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