# Huge number of 'elasticsearch\[cached\]-pool-1-thread-NNN' threads **URL:** \ **Category:** Elasticsearch\ **Created:** [May 8, 2011, 6:53am UTC](https://discuss.elastic.co/t/huge-number-of-elasticsearch-cached-pool-1-thread-nnn-threads/4362 "2011-05-08T06:53:28Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![jordansissel](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/jordansissel/32/44957_2.png) [@jordansissel](https://discuss.elastic.co/u/jordansissel)\ **Post date:** [May 8, 2011, 6:53am UTC](https://discuss.elastic.co/t/huge-number-of-elasticsearch-cached-pool-1-thread-nnn-threads/4362/1 "2011-05-08T06:53:28Z")
While helping someone debug a logstash issue tonight, we noticed that for an elasticsearch native java client had 1700 elasticsearch threads. After further digging, I concluded that the high thread count for elasticsearch, while abnormal, was not related to the problem I was debugging. Emailing the list anyway to get some details about what is going on - Here's a breakdown of elasticsearch threads according to jstack: % grep '^"' logstash.jstack | fex '"1' | sed -re 's/[0-9]+/XXX/g' |sort| uniq -c | sort -n | grep elastic 1 elasticsearch[Artemis]clusterService#updateTask-pool-XXX-thread-XXX 1 elasticsearch[Artemis][scheduler]-pool-XXX-thread-XXX 1 elasticsearch[Artemis][timer] 1 elasticsearch[Artemis]transport\_client\_boss-pool-XXX-thread-XXX 6 elasticsearch[Artemis]transport\_client\_worker-pool-XXX-thread-XXX 1694 elasticsearch[cached]-pool-XXX-thread-XXX What are these 'cached' pool threads? Why would there be almost 1700 of them? Are they pending queries? Something else? -Jordan ---
**Author:** ![kimchy](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/kimchy/32/44952_2.png) [@kimchy](https://discuss.elastic.co/u/kimchy)\ **Post date:** [May 8, 2011, 6:56am UTC](https://discuss.elastic.co/t/huge-number-of-elasticsearch-cached-pool-1-thread-nnn-threads/4362/2 "2011-05-08T06:56:13Z")
Which version of elasticsearch are you using? The thread pool names changed between versions. On Sunday, May 8, 2011 at 9:53 AM, Jordan Sissel wrote: > While helping someone debug a logstash issue tonight, we noticed that for an elasticsearch native java client had 1700 elasticsearch threads. After further digging, I concluded that the high thread count for elasticsearch, while abnormal, was not related to the problem I was debugging. > > Emailing the list anyway to get some details about what is going on - > > Here's a breakdown of elasticsearch threads according to jstack: > > % grep '^"' logstash.jstack | fex '"1' | sed -re 's/[0-9]+/XXX/g' |sort| uniq -c | sort -n | grep elastic > 1 elasticsearch[Artemis]clusterService#updateTask-pool-XXX-thread-XXX > 1 elasticsearch[Artemis][scheduler]-pool-XXX-thread-XXX > 1 elasticsearch[Artemis][timer] > 1 elasticsearch[Artemis]transport\_client\_boss-pool-XXX-thread-XXX > 6 elasticsearch[Artemis]transport\_client\_worker-pool-XXX-thread-XXX > 1694 elasticsearch[cached]-pool-XXX-thread-XXX > > What are these 'cached' pool threads? Why would there be almost 1700 of them? > > Are they pending queries? Something else? > > -Jordan ---
**Author:** ![jordansissel](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/jordansissel/32/44957_2.png) [@jordansissel](https://discuss.elastic.co/u/jordansissel)\ **Post date:** [May 9, 2011, 12:29am UTC](https://discuss.elastic.co/t/huge-number-of-elasticsearch-cached-pool-1-thread-nnn-threads/4362/3 "2011-05-09T00:29:21Z")
On Sat, May 7, 2011 at 11:56 PM, Shay Banon [shay.banon@elasticsearch.com](mailto:shay.banon@elasticsearch.com)wrote: > Which version of elasticsearch are you using? The thread pool names > changed between versions. The client I shipped should be version 0.16.0 -Jordan On Sunday, May 8, 2011 at 9:53 AM, Jordan Sissel wrote: > While helping someone debug a logstash issue tonight, we noticed that for > an elasticsearch native java client had 1700 elasticsearch threads. After > further digging, I concluded that the high thread count for elasticsearch, > while abnormal, was not related to the problem I was debugging. > > Emailing the list anyway to get some details about what is going on - > > Here's a breakdown of elasticsearch threads according to jstack: > > % grep '^"' logstash.jstack | fex '"1' | sed -re 's/[0-9]+/XXX/g' |sort| > uniq -c | sort -n | grep elastic > 1 elasticsearch[Artemis]clusterService#updateTask-pool-XXX-thread-XXX > 1 elasticsearch[Artemis][scheduler]-pool-XXX-thread-XXX > 1 elasticsearch[Artemis][timer] > 1 elasticsearch[Artemis]transport\_client\_boss-pool-XXX-thread-XXX > 6 elasticsearch[Artemis]transport\_client\_worker-pool-XXX-thread-XXX > 1694 elasticsearch[cached]-pool-XXX-thread-XXX > > What are these 'cached' pool threads? Why would there be almost 1700 of > them? > > Are they pending queries? Something else? > > -Jordan ---
**Author:** ![kimchy](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/kimchy/32/44952_2.png) [@kimchy](https://discuss.elastic.co/u/kimchy)\ **Post date:** [May 9, 2011, 8:48am UTC](https://discuss.elastic.co/t/huge-number-of-elasticsearch-cached-pool-1-thread-nnn-threads/4362/4 "2011-05-09T08:48:41Z")
Then thats strange, I would expect to see other elasticsearch threads in this case. Which client are you using in this case, the NodeClient or the TransportClient? On Monday, May 9, 2011 at 3:29 AM, Jordan Sissel wrote: > On Sat, May 7, 2011 at 11:56 PM, Shay Banon [shay.banon@elasticsearch.com](mailto:shay.banon@elasticsearch.com) wrote: > > > Which version of elasticsearch are you using? The thread pool names changed between versions. > > The client I shipped should be version 0.16.0 > > -Jordan > > > On Sunday, May 8, 2011 at 9:53 AM, Jordan Sissel wrote: > > > > > While helping someone debug a logstash issue tonight, we noticed that for an elasticsearch native java client had 1700 elasticsearch threads. After further digging, I concluded that the high thread count for elasticsearch, while abnormal, was not related to the problem I was debugging. > > > > > > Emailing the list anyway to get some details about what is going on - > > > > > > Here's a breakdown of elasticsearch threads according to jstack: > > > > > > % grep '^"' logstash.jstack | fex '"1' | sed -re 's/[0-9]+/XXX/g' |sort| uniq -c | sort -n | grep elastic > > > 1 elasticsearch[Artemis]clusterService#updateTask-pool-XXX-thread-XXX > > > 1 elasticsearch[Artemis][scheduler]-pool-XXX-thread-XXX > > > 1 elasticsearch[Artemis][timer] > > > 1 elasticsearch[Artemis]transport\_client\_boss-pool-XXX-thread-XXX > > > 6 elasticsearch[Artemis]transport\_client\_worker-pool-XXX-thread-XXX > > > 1694 elasticsearch[cached]-pool-XXX-thread-XXX > > > > > > What are these 'cached' pool threads? Why would there be almost 1700 of them? > > > > > > Are they pending queries? Something else? > > > > > > -Jordan ---
**Author:** ![jordansissel](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/jordansissel/32/44957_2.png) [@jordansissel](https://discuss.elastic.co/u/jordansissel)\ **Post date:** [May 9, 2011, 8:11pm UTC](https://discuss.elastic.co/t/huge-number-of-elasticsearch-cached-pool-1-thread-nnn-threads/4362/5 "2011-05-09T20:11:12Z")
On Mon, May 9, 2011 at 1:48 AM, Shay Banon [shay.banon@elasticsearch.com](mailto:shay.banon@elasticsearch.com)wrote: > Then thats strange, I would expect to see other elasticsearch threads in > this case. Which client are you using in this case, the NodeClient or the > TransportClient? I believe the 'node' client? Though I don't know for sure, here's the code that creates it: org.elasticsearch.node.NodeBuilder.nodeBuilder.client(true).node.client -Jordan On Monday, May 9, 2011 at 3:29 AM, Jordan Sissel wrote: > On Sat, May 7, 2011 at 11:56 PM, Shay Banon [shay.banon@elasticsearch.com](mailto:shay.banon@elasticsearch.com)wrote: > > Which version of elasticsearch are you using? The thread pool names > changed between versions. > > The client I shipped should be version 0.16.0 > > -Jordan > > On Sunday, May 8, 2011 at 9:53 AM, Jordan Sissel wrote: > > While helping someone debug a logstash issue tonight, we noticed that for > an elasticsearch native java client had 1700 elasticsearch threads. After > further digging, I concluded that the high thread count for elasticsearch, > while abnormal, was not related to the problem I was debugging. > > Emailing the list anyway to get some details about what is going on - > > Here's a breakdown of elasticsearch threads according to jstack: > > % grep '^"' logstash.jstack | fex '"1' | sed -re 's/[0-9]+/XXX/g' |sort| > uniq -c | sort -n | grep elastic > 1 elasticsearch[Artemis]clusterService#updateTask-pool-XXX-thread-XXX > 1 elasticsearch[Artemis][scheduler]-pool-XXX-thread-XXX > 1 elasticsearch[Artemis][timer] > 1 elasticsearch[Artemis]transport\_client\_boss-pool-XXX-thread-XXX > 6 elasticsearch[Artemis]transport\_client\_worker-pool-XXX-thread-XXX > 1694 elasticsearch[cached]-pool-XXX-thread-XXX > > What are these 'cached' pool threads? Why would there be almost 1700 of > them? > > Are they pending queries? Something else? > > -Jordan ---
**Author:** ![kimchy](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/kimchy/32/44952_2.png) [@kimchy](https://discuss.elastic.co/u/kimchy)\ **Post date:** [May 10, 2011, 9:11pm UTC](https://discuss.elastic.co/t/huge-number-of-elasticsearch-cached-pool-1-thread-nnn-threads/4362/6 "2011-05-10T21:11:25Z")
Yea, thats the node client. strange... . I will try and run some tests to see if I can repro, if you can do the same, it would be great... On Monday, May 9, 2011 at 11:11 PM, Jordan Sissel wrote: > On Mon, May 9, 2011 at 1:48 AM, Shay Banon [shay.banon@elasticsearch.com](mailto:shay.banon@elasticsearch.com) wrote: > > > Then thats strange, I would expect to see other elasticsearch threads in this case. Which client are you using in this case, the NodeClient or the TransportClient? > > I believe the 'node' client? Though I don't know for sure, here's the code that creates it: > > org.elasticsearch.node.NodeBuilder.nodeBuilder.client(true).node.client > > -Jordan > > > On Monday, May 9, 2011 at 3:29 AM, Jordan Sissel wrote: > > > > > On Sat, May 7, 2011 at 11:56 PM, Shay Banon [shay.banon@elasticsearch.com](mailto:shay.banon@elasticsearch.com) wrote: > > > > > > > Which version of elasticsearch are you using? The thread pool names changed between versions. > > > > > > The client I shipped should be version 0.16.0 > > > > > > -Jordan > > > > > > > On Sunday, May 8, 2011 at 9:53 AM, Jordan Sissel wrote: > > > > > > > > > While helping someone debug a logstash issue tonight, we noticed that for an elasticsearch native java client had 1700 elasticsearch threads. After further digging, I concluded that the high thread count for elasticsearch, while abnormal, was not related to the problem I was debugging. > > > > > > > > > > Emailing the list anyway to get some details about what is going on - > > > > > > > > > > Here's a breakdown of elasticsearch threads according to jstack: > > > > > > > > > > % grep '^"' logstash.jstack | fex '"1' | sed -re 's/[0-9]+/XXX/g' |sort| uniq -c | sort -n | grep elastic > > > > > 1 elasticsearch[Artemis]clusterService#updateTask-pool-XXX-thread-XXX > > > > > 1 elasticsearch[Artemis][scheduler]-pool-XXX-thread-XXX > > > > > 1 elasticsearch[Artemis][timer] > > > > > 1 elasticsearch[Artemis]transport\_client\_boss-pool-XXX-thread-XXX > > > > > 6 elasticsearch[Artemis]transport\_client\_worker-pool-XXX-thread-XXX > > > > > 1694 elasticsearch[cached]-pool-XXX-thread-XXX > > > > > > > > > > What are these 'cached' pool threads? Why would there be almost 1700 of them? > > > > > > > > > > Are they pending queries? Something else? > > > > > > > > > > -Jordan ---
**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\ **Post date:** [July 6, 2017, 4:06am UTC](https://discuss.elastic.co/t/huge-number-of-elasticsearch-cached-pool-1-thread-nnn-threads/4362/7 "2017-07-06T04:06:32Z")