# ES system CPU spikes to 100% despite of having small amount of data

**URL:** <https://discuss.elastic.co/t/es-system-cpu-spikes-to-100-despite-of-having-small-amount-of-data/79173>\
**Category:** Elasticsearch\
**Created:** [March 19, 2017, 2:48pm UTC](https://discuss.elastic.co/t/es-system-cpu-spikes-to-100-despite-of-having-small-amount-of-data/79173 "2017-03-19T14:48:17Z")\
**Posts on this page:** 5\
**Page:** 1

<div class="post-metadata">

**Author:** ![raj.shah1593](https://avatars.discourse-cdn.com/v4/letter/r/8edcca/32.png) [@raj.shah1593](https://discuss.elastic.co/u/raj.shah1593)\
**Post date:** [March 19, 2017, 2:48pm UTC](https://discuss.elastic.co/t/es-system-cpu-spikes-to-100-despite-of-having-small-amount-of-data/79173/1 "2017-03-19T14:48:17Z")

</div>

Hello,

I am using Elastic Search v5.2.2.  
I have a single node cluster with 3 primary shards & 0 replica shard.  
Total documents are around 10 million with 5 GB of data.

I have disabled scoring and most of the fields in my index are not\_analyzed.  
I am also using the pre-load feature where I load all the files (index.store.preload : ["\*"]) before beginning the search operations.

Currently, I have 128 GB RAM and 1.5 TB of hard disk....Heap size is set to 8 GB.

Inspite of having such a small amount of data and a high performance machine, my CPU spikes to 100% and performance is not as expected.

What might be the reason for such slow performance?  
And what can be interpreted from the following hot thread output? I can see Scorers in the output even though I have disabled scoring.

Thanks 🙂

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<div class="post-metadata">

**Author:** ![raj.shah1593](https://avatars.discourse-cdn.com/v4/letter/r/8edcca/32.png) [@raj.shah1593](https://discuss.elastic.co/u/raj.shah1593)\
**Post date:** [March 19, 2017, 2:52pm UTC](https://discuss.elastic.co/t/es-system-cpu-spikes-to-100-despite-of-having-small-amount-of-data/79173/2 "2017-03-19T14:52:51Z")

</div>

```
::: {sys217}{NDgCEjjcT9CT32i4JlMmWQ}{FILT-0ulRc64Osy1EIUICw}{172.24.22.217}{172.24.22.217:9300}
   Hot threads at 2017-03-19T13:30:33.282Z, interval=500ms, busiestThreads=3, ignoreIdleThreads=true:
   
   81.1% (405.6ms out of 500ms) cpu usage by thread 'elasticsearch[sys217][search][T#12]'
     2/10 snapshots sharing following 23 elements
       org.apache.lucene.codecs.blocktree.IntersectTermsEnum.next(IntersectTermsEnum.java:500)
       org.apache.lucene.search.MultiTermQueryConstantScoreWrapper$1.rewrite(MultiTermQueryConstantScoreWrapper.java:176)
       org.apache.lucene.search.MultiTermQueryConstantScoreWrapper$1.scorer(MultiTermQueryConstantScoreWrapper.java:208)
       org.apache.lucene.search.BooleanWeight.scorer(BooleanWeight.java:389)
       org.apache.lucene.search.Weight.bulkScorer(Weight.java:135)
       org.apache.lucene.search.BooleanWeight.bulkScorer(BooleanWeight.java:370)
       org.elasticsearch.search.query.QueryPhase.execute(QueryPhase.java:106)
       org.elasticsearch.search.SearchService.loadOrExecuteQueryPhase(SearchService.java:246)
       org.elasticsearch.search.SearchService.executeQueryPhase(SearchService.java:260)
       org.elasticsearch.action.search.SearchTransportService$6.messageReceived(SearchTransportService.java:298)
       org.elasticsearch.transport.RequestHandlerRegistry.processMessageReceived(RequestHandlerRegistry.java:69)
       org.elasticsearch.transport.TransportService$7.doRun(TransportService.java:610)
       org.elasticsearch.common.util.concurrent.ThreadContext$ContextPreservingAbstractRunnable.doRun(ThreadContext.java:596)
       org.elasticsearch.common.util.concurrent.AbstractRunnable.run(AbstractRunnable.java:37)
       java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
       java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
       java.lang.Thread.run(Thread.java:745)
     2/10 snapshots sharing following 31 elements
       org.apache.lucene.util.automaton.Operations.determinize(Operations.java:728)
       org.apache.lucene.util.automaton.Operations.getCommonSuffixBytesRef(Operations.java:1163)
       org.apache.lucene.util.automaton.CompiledAutomaton.<init>(CompiledAutomaton.java:238)
       org.apache.lucene.search.AutomatonQuery.<init>(AutomatonQuery.java:102)
       org.apache.lucene.search.TermRangeQuery.<init>(TermRangeQuery.java:66)
       org.elasticsearch.index.mapper.StringFieldType.rangeQuery(StringFieldType.java:93)
       org.elasticsearch.index.query.RangeQueryBuilder.doToQuery(RangeQueryBuilder.java:517)
       org.elasticsearch.index.query.AbstractQueryBuilder.toQuery(AbstractQueryBuilder.java:97)
       org.elasticsearch.transport.RequestHandlerRegistry.processMessageReceived(RequestHandlerRegistry.java:69)
       org.elasticsearch.transport.TransportService$7.doRun(TransportService.java:610)
       org.elasticsearch.common.util.concurrent.ThreadContext$ContextPreservingAbstractRunnable.doRun(ThreadContext.java:596)
       org.elasticsearch.common.util.concurrent.AbstractRunnable.run(AbstractRunnable.java:37)
       java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
       java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
       java.lang.Thread.run(Thread.java:745)
     2/10 snapshots sharing following 19 elements
       org.apache.lucene.search.BooleanWeight.scorer(BooleanWeight.java:389)
       org.apache.lucene.search.Weight.bulkScorer(Weight.java:135)
       org.apache.lucene.search.BooleanWeight.bulkScorer(BooleanWeight.java:370)
       org.elasticsearch.search.query.QueryPhase.execute(QueryPhase.java:106)
       org.elasticsearch.search.SearchService.executeQueryPhase(SearchService.java:260)
                  org.elasticsearch.action.search.SearchTransportService$6.messageReceived(SearchTransportService.java:295)
       org.elasticsearch.transport.RequestHandlerRegistry.processMessageReceived(RequestHandlerRegistry.java:69)
       org.elasticsearch.transport.TransportService$7.doRun(TransportService.java:610)
       org.elasticsearch.common.util.concurrent.ThreadContext$ContextPreservingAbstractRunnable.doRun(ThreadContext.java:596)
       org.elasticsearch.common.util.concurrent.AbstractRunnable.run(AbstractRunnable.java:37)
       java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
       java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
       java.lang.Thread.run(Thread.java:745)
     2/10 snapshots sharing following 26 elements
       java.lang.Throwable.fillInStackTrace(Native Method)
       java.lang.Throwable.fillInStackTrace(Throwable.java:783)
       java.lang.Throwable.<init>(Throwable.java:250)
       java.lang.Error.<init>(Error.java:58)

       org.apache.lucene.queryparser.classic.MapperQueryParser.<init>(MapperQueryParser.java:86)
       org.elasticsearch.index.query.QueryShardContext.<init>(QueryShardContext.java:94)
       org.elasticsearch.index.IndexService.newQueryShardContext(IndexService.java:470)
       org.elasticsearch.search.DefaultSearchContext.<init>(DefaultSearchContext.java:171)
       org.elasticsearch.action.search.SearchTransportService$6.messageReceived(SearchTransportService.java:298)
       
       org.apache.lucene.util.automaton.Operations.getCommonSuffixBytesRef(Operations.java:1163)
       org.apache.lucene.util.automaton.CompiledAutomaton.<init>(CompiledAutomaton.java:238)
       org.apache.lucene.search.AutomatonQuery.<init>(AutomatonQuery.java:102)
       org.apache.lucene.search.TermRangeQuery.<init>(TermRangeQuery.java:66)
       org.elasticsearch.index.mapper.StringFieldType.rangeQuery(StringFieldType.java:93)
       org.elasticsearch.index.query.RangeQueryBuilder.doToQuery(RangeQueryBuilder.java:517)
       org.elasticsearch.index.query.AbstractQueryBuilder.toQuery(AbstractQueryBuilder.java:97)
       org.elasticsearch.transport.RequestHandlerRegistry.processMessageReceived(RequestHandlerRegistry.java:69)
       org.elasticsearch.transport.TransportService$7.doRun(TransportService.java:610)
       org.elasticsearch.common.util.concurrent.ThreadContext$ContextPreservingAbstractRunnable.doRun(ThreadContext.java:596)
       org.elasticsearch.common.util.concurrent.AbstractRunnable.run(AbstractRunnable.java:37)
       java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
       java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
       java.lang.Thread.run(Thread.java:745)
```

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<div class="post-metadata">

**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:** [March 19, 2017, 10:50pm UTC](https://discuss.elastic.co/t/es-system-cpu-spikes-to-100-despite-of-having-small-amount-of-data/79173/3 "2017-03-19T22:50:20Z")

</div>

What sort of searches are you doing?

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<div class="post-metadata">

**Author:** ![raj.shah1593](https://avatars.discourse-cdn.com/v4/letter/r/8edcca/32.png) [@raj.shah1593](https://discuss.elastic.co/u/raj.shah1593)\
**Post date:** [March 20, 2017, 3:04am UTC](https://discuss.elastic.co/t/es-system-cpu-spikes-to-100-despite-of-having-small-amount-of-data/79173/4 "2017-03-20T03:04:53Z")

</div>

I am using multisearch where i have 5 individual queries on different fields.  
All the queries perform search on a single index.

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<div class="post-metadata">

**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\
**Post date:** [April 17, 2017, 3:04am UTC](https://discuss.elastic.co/t/es-system-cpu-spikes-to-100-despite-of-having-small-amount-of-data/79173/5 "2017-04-17T03:04:56Z")

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