# Bad performance of 2-node-cluster **URL:** \ **Category:** Elasticsearch\ **Created:** [March 19, 2014, 9:36am UTC](https://discuss.elastic.co/t/bad-performance-of-2-node-cluster/16455 "2014-03-19T09:36:34Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![Herbert\_Bodner](https://avatars.discourse-cdn.com/v4/letter/h/a4c791/32.png) [@Herbert\_Bodner](https://discuss.elastic.co/u/Herbert_Bodner)\ **Post date:** [March 19, 2014, 9:36am UTC](https://discuss.elastic.co/t/bad-performance-of-2-node-cluster/16455/1 "2014-03-19T09:36:34Z")
Hey, I have about 7 million documents in my ES cluster using default configurations (5 shards, 1 replica). I set up 4 virtual machines with similar configurations on a 8 core server, each virtual machine assigned with 2 virtual cores and 4 GB memory. On each node I installed Elasticsearch. I did several search tests to measure query response time and the results are a bit confusing: 1. When using only a single node, I get the best response time. 2. When using a 2-node cluster response time increases significantly, meaning the response time gets worse (the more found documents the worse the response time) 3. For a three- or four-node cluster the response time improves again and is at the level of the single-node configuration. Any idea why the 2-node cluster has such a bad performance compared to the other configurations? cheers Herbert -- 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). To view this discussion on the web visit [https://groups.google.com/d/msgid/elasticsearch/4068f0a2-50dc-4f4a-9f51-6e12dced4e80%40googlegroups.com](https://groups.google.com/d/msgid/elasticsearch/4068f0a2-50dc-4f4a-9f51-6e12dced4e80%40googlegroups.com). For more options, visit [https://groups.google.com/d/optout](https://groups.google.com/d/optout). ---
**Author:** ![jprante](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/jprante/32/44941_2.png) [@jprante](https://discuss.elastic.co/u/jprante)\ **Post date:** [March 19, 2014, 1:25pm UTC](https://discuss.elastic.co/t/bad-performance-of-2-node-cluster/16455/2 "2014-03-19T13:25:45Z")
Why do you set up more than one JVM per machine? Jörg On Wed, Mar 19, 2014 at 10:36 AM, Herbert Bodner [herbert.bodner@gmail.com](mailto:herbert.bodner@gmail.com)wrote: > Hey, > I have about 7 million documents in my ES cluster using default > configurations (5 shards, 1 replica). > I set up 4 virtual machines with similar configurations on a 8 core > server, each virtual machine assigned with 2 virtual cores and 4 GB memory. > On each node I installed Elasticsearch. > I did several search tests to measure query response time and the results > are a bit confusing: > > 1. When using only a single node, I get the best response time. > 2. When using a 2-node cluster response time increases significantly, > meaning the response time gets worse (the more found documents the worse > the response time) > 3. For a three- or four-node cluster the response time improves again and > is at the level of the single-node configuration. > > Any idea why the 2-node cluster has such a bad performance compared to the > other configurations? > > cheers > Herbert > > -- > 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). > To view this discussion on the web visit > [https://groups.google.com/d/msgid/elasticsearch/4068f0a2-50dc-4f4a-9f51-6e12dced4e80%40googlegroups.com](https://groups.google.com/d/msgid/elasticsearch/4068f0a2-50dc-4f4a-9f51-6e12dced4e80%40googlegroups.com)[https://groups.google.com/d/msgid/elasticsearch/4068f0a2-50dc-4f4a-9f51-6e12dced4e80%40googlegroups.com?utm\_medium=email&utm\_source=footer](https://groups.google.com/d/msgid/elasticsearch/4068f0a2-50dc-4f4a-9f51-6e12dced4e80%40googlegroups.com?utm_medium=email&utm_source=footer) > . > For more options, visit [https://groups.google.com/d/optout](https://groups.google.com/d/optout). -- 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). To view this discussion on the web visit [https://groups.google.com/d/msgid/elasticsearch/CAKdsXoGF%3DhT5BbT8dR6nuBq29CPB75kjY-SDwNvSZDX9tV%3DjDA%40mail.gmail.com](https://groups.google.com/d/msgid/elasticsearch/CAKdsXoGF%3DhT5BbT8dR6nuBq29CPB75kjY-SDwNvSZDX9tV%3DjDA%40mail.gmail.com). For more options, visit [https://groups.google.com/d/optout](https://groups.google.com/d/optout). ---
**Author:** ![Herbert\_Bodner](https://avatars.discourse-cdn.com/v4/letter/h/a4c791/32.png) [@Herbert\_Bodner](https://discuss.elastic.co/u/Herbert_Bodner)\ **Post date:** [March 19, 2014, 1:52pm UTC](https://discuss.elastic.co/t/bad-performance-of-2-node-cluster/16455/3 "2014-03-19T13:52:45Z")
> Why do you set up more than one JVM per machine? I didn´t do that!? One Elasticsearch-Installation on each of the four virtual machines. -- 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). To view this discussion on the web visit [https://groups.google.com/d/msgid/elasticsearch/0dd8ca64-4f29-4dcb-8c1c-cecaf2f35f3a%40googlegroups.com](https://groups.google.com/d/msgid/elasticsearch/0dd8ca64-4f29-4dcb-8c1c-cecaf2f35f3a%40googlegroups.com). For more options, visit [https://groups.google.com/d/optout](https://groups.google.com/d/optout). ---
**Author:** ![Herbert\_Bodner](https://avatars.discourse-cdn.com/v4/letter/h/a4c791/32.png) [@Herbert\_Bodner](https://discuss.elastic.co/u/Herbert_Bodner)\ **Post date:** [March 24, 2014, 8:31am UTC](https://discuss.elastic.co/t/bad-performance-of-2-node-cluster/16455/4 "2014-03-24T08:31:16Z")
I guess I found the problem: The results that 2 nodes perform much worse, cannot be reproduced. There has been going on something else on the server at that time when I executed the tests for 2 nodes, which influenced the results. (Probably somebody copied a large file to or from the server, which made the disk kind of busy) -- 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). To view this discussion on the web visit [https://groups.google.com/d/msgid/elasticsearch/67983dda-dcf0-4ef5-a566-8a7a00f51761%40googlegroups.com](https://groups.google.com/d/msgid/elasticsearch/67983dda-dcf0-4ef5-a566-8a7a00f51761%40googlegroups.com). For more options, visit [https://groups.google.com/d/optout](https://groups.google.com/d/optout). ---
**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, 1:41am UTC](https://discuss.elastic.co/t/bad-performance-of-2-node-cluster/16455/5 "2017-07-06T01:41:14Z")