# Elasticsearch merge slowness **URL:** \ **Category:** Elasticsearch\ **Created:** [May 4, 2013, 5:28am UTC](https://discuss.elastic.co/t/elasticsearch-merge-slowness/11807 "2013-05-04T05:28:15Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![Alexis\_Okuwa](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/alexis_okuwa/32/1983_2.png) [@Alexis\_Okuwa](https://discuss.elastic.co/u/Alexis_Okuwa)\ **Post date:** [May 4, 2013, 5:28am UTC](https://discuss.elastic.co/t/elasticsearch-merge-slowness/11807/1 "2013-05-04T05:28:15Z")
Yesterday i thought there was with my small vm (2gb ram, 2gb disk) and a million items in my es database, So I started dropping types in the same index, in the end dropped 70k types and did not solve the issue (something else was the issue), none the less elasticsearch paid me a visit with merging documents i deleted out. This took over 12 hours and it was doing it in bulk and when it did them CPU went up for a while 1-5 minutes. Is this suppopse to happen or is merge suppose to be a little more gentail. -- You received this message because you are subscribed to the Google Groups "elasticsearch" group. To unsubscribe from this group and stop receiving emails from it, send an email to [elasticsearch+unsubscribe@googlegroups.com](mailto:elasticsearch+unsubscribe@googlegroups.com). For more options, visit [https://groups.google.com/groups/opt\_out](https://groups.google.com/groups/opt_out). ---
**Author:** ![radu\_gheorghe](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/radu_gheorghe/32/556_2.png) [@radu\_gheorghe](https://discuss.elastic.co/u/radu_gheorghe)\ **Post date:** [May 4, 2013, 7:52am UTC](https://discuss.elastic.co/t/elasticsearch-merge-slowness/11807/2 "2013-05-04T07:52:19Z")
Hello, I guess merging can be painfull if it's caused by massive deletes on a small vm, because you can get up to 30 going on at the same time, if my understanding is correct (index.merge.policy.max\_merge\_at\_once\_explicit is 30 by default). You should be able to make it more gentle by reducing that number though from the index settings[http://www.elasticsearch.org/guide/reference/api/admin-indices-update-settings/](http://www.elasticsearch.org/guide/reference/api/admin-indices-update-settings/) . Also, if your CPU load is caused by I/O waits, store throttling[http://www.elasticsearch.org/guide/reference/index-modules/store/](http://www.elasticsearch.org/guide/reference/index-modules/store/)might also help. ## Best regards, Radu [http://sematext.com/](http://sematext.com/) -- Elasticsearch -- Solr -- Lucene On Sat, May 4, 2013 at 8:28 AM, Wojons Tech [wojonstech@gmail.com](mailto:wojonstech@gmail.com) wrote: > Yesterday i thought there was with my small vm (2gb ram, 2gb disk) and a > million items in my es database, So I started dropping types in the same > index, in the end dropped 70k types and did not solve the issue (something > else was the issue), none the less elasticsearch paid me a visit with > merging documents i deleted out. This took over 12 hours and it was doing > it in bulk and when it did them CPU went up for a while 1-5 minutes. Is > this suppopse to happen or is merge suppose to be a little more gentail. > > -- > You received this message because you are subscribed to the Google Groups > "elasticsearch" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [elasticsearch+unsubscribe@googlegroups.com](mailto:elasticsearch+unsubscribe@googlegroups.com). > For more options, visit [https://groups.google.com/groups/opt\_out](https://groups.google.com/groups/opt_out). -- You received this message because you are subscribed to the Google Groups "elasticsearch" group. To unsubscribe from this group and stop receiving emails from it, send an email to [elasticsearch+unsubscribe@googlegroups.com](mailto:elasticsearch+unsubscribe@googlegroups.com). For more options, visit [https://groups.google.com/groups/opt\_out](https://groups.google.com/groups/opt_out). ---
**Author:** ![Alexis\_Okuwa](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/alexis_okuwa/32/1983_2.png) [@Alexis\_Okuwa](https://discuss.elastic.co/u/Alexis_Okuwa)\ **Post date:** [May 4, 2013, 7:55am UTC](https://discuss.elastic.co/t/elasticsearch-merge-slowness/11807/3 "2013-05-04T07:55:38Z")
Okay so I will look at lowering that number to something resonable for the size of my vm. Also the link to store throttling is very intresting and i am going to try that out. The goal is to have indexes by date and alias them but for dev i am just storing everything in the same one until i write the code to handle that. On Sat, May 4, 2013 at 12:52 AM, Radu Gheorghe [radu.gheorghe@sematext.com](mailto:radu.gheorghe@sematext.com)wrote: > Hello, > > I guess merging can be painfull if it's caused by massive deletes on a > small vm, because you can get up to 30 going on at the same time, if my > understanding is correct (index.merge.policy.max\_merge\_at\_once\_explicit is > 30 by default). > > You should be able to make it more gentle by reducing that number though > from the index settings[http://www.elasticsearch.org/guide/reference/api/admin-indices-update-settings/](http://www.elasticsearch.org/guide/reference/api/admin-indices-update-settings/) > . > > Also, if your CPU load is caused by I/O waits, store throttling[http://www.elasticsearch.org/guide/reference/index-modules/store/](http://www.elasticsearch.org/guide/reference/index-modules/store/)might also help. > > ## Best regards, Radu > > [http://sematext.com/](http://sematext.com/) -- Elasticsearch -- Solr -- Lucene > > On Sat, May 4, 2013 at 8:28 AM, Wojons Tech [wojonstech@gmail.com](mailto:wojonstech@gmail.com) wrote: > > > Yesterday i thought there was with my small vm (2gb ram, 2gb disk) and a > > million items in my es database, So I started dropping types in the same > > index, in the end dropped 70k types and did not solve the issue (something > > else was the issue), none the less elasticsearch paid me a visit with > > merging documents i deleted out. This took over 12 hours and it was doing > > it in bulk and when it did them CPU went up for a while 1-5 minutes. Is > > this suppopse to happen or is merge suppose to be a little more gentail. > > > > -- > > You received this message because you are subscribed to the Google Groups > > "elasticsearch" group. > > To unsubscribe from this group and stop receiving emails from it, send an > > email to [elasticsearch+unsubscribe@googlegroups.com](mailto:elasticsearch+unsubscribe@googlegroups.com). > > > > For more options, visit [https://groups.google.com/groups/opt\_out](https://groups.google.com/groups/opt_out). > > -- > You received this message because you are subscribed to a topic in the > Google Groups "elasticsearch" group. > To unsubscribe from this topic, visit > [https://groups.google.com/d/topic/elasticsearch/1fyUmiqQzWc/unsubscribe?hl=en-US](https://groups.google.com/d/topic/elasticsearch/1fyUmiqQzWc/unsubscribe?hl=en-US) > . > To unsubscribe from this group and all its topics, send an email to > [elasticsearch+unsubscribe@googlegroups.com](mailto:elasticsearch+unsubscribe@googlegroups.com). > For more options, visit [https://groups.google.com/groups/opt\_out](https://groups.google.com/groups/opt_out). -- Enjoy, Alexis Okuwa WojonsTech 424.835.1223 -- You received this message because you are subscribed to the Google Groups "elasticsearch" group. To unsubscribe from this group and stop receiving emails from it, send an email to [elasticsearch+unsubscribe@googlegroups.com](mailto:elasticsearch+unsubscribe@googlegroups.com). For more options, visit [https://groups.google.com/groups/opt\_out](https://groups.google.com/groups/opt_out). ---
**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, 2:38am UTC](https://discuss.elastic.co/t/elasticsearch-merge-slowness/11807/4 "2017-07-06T02:38:21Z")