# Running more than one ES instance on the same server while indexing data **URL:** \ **Category:** Elasticsearch\ **Created:** [November 18, 2011, 8:03pm UTC](https://discuss.elastic.co/t/running-more-than-one-es-instance-on-the-same-server-while-indexing-data/5913 "2011-11-18T20:03:35Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![Frederic](https://avatars.discourse-cdn.com/v4/letter/f/4491bb/32.png) [@Frederic](https://discuss.elastic.co/u/Frederic)\ **Post date:** [November 18, 2011, 8:03pm UTC](https://discuss.elastic.co/t/running-more-than-one-es-instance-on-the-same-server-while-indexing-data/5913/1 "2011-11-18T20:03:35Z")
Hey guys, hope you can help me with this. By mistake, two instances of ES were launched (at the same 9200 port) on al least 4 servers of a 8 nodes cluster. That happened while multiple processes were indexing docs. After shutting down these extra instances and restarting the cluster, the state was in RED as 2 shards were unassigned. Today I restarted all nodes one by one and the cluster health got Green. From my tests on localhost, new ES instances running on the same machine form a cluster like any other node and reallocate shards among them, is this correct? If so, I understand that shutting down ES instances would act as if a node was stopped, regardless if some instances are running on the same server, correct? If not... is there any chance that information sotred previously to the problem could be lost/corrupted because sharding reallocation between these multiple instances of ES? Thanks a lot for this great product, ---
**Author:** ![Karussell1](https://avatars.discourse-cdn.com/v4/letter/k/50afbb/32.png) [@Karussell1](https://discuss.elastic.co/u/Karussell1)\ **Post date:** [November 18, 2011, 11:47pm UTC](https://discuss.elastic.co/t/running-more-than-one-es-instance-on-the-same-server-while-indexing-data/5913/2 "2011-11-18T23:47:41Z")
> After shutting down these extra instances and restarting the cluster, > the state was in RED as 2 shards were unassigned. How did you shut them down? one by one until cluster reached green? E.g. if you shutdown two instances which have two replicas of a shard (and you only have two) this shard cannot be reassigned ... > From my tests on localhost, new ES instances running on the same > machine form a cluster like any other node and reallocate shards among them, is this correct? yes, but not only on the same machine ... you can avoid that via the cluster name > If so, I understand that shutting down ES instances would act as if a > node was stopped, regardless if some instances are running on the same server, correct? what do you mean here? > If not... is there any chance that information sotred previously to the problem could be lost/corrupted because sharding > reallocation between these multiple instances of ES? IMO no Regards, Peter. On Nov 18, 9:03 pm, Frederic [focampo...@gmail.com](mailto:focampo...@gmail.com) wrote: > Hey guys, hope you can help me with this. > > By mistake, two instances of ES were launched (at the same 9200 port) > on al least 4 servers of a 8 nodes cluster. That happened while > multiple processes were indexing docs. > > After shutting down these extra instances and restarting the cluster, > the state was in RED as 2 shards were unassigned. Today I restarted > all nodes one by one and the cluster health got Green. > > From my tests on localhost, new ES instances running on the same > machine form a cluster like any other node and reallocate shards among > them, is this correct? > > If so, I understand that shutting down ES instances would act as if a > node was stopped, regardless if some instances are running on the same > server, correct? > > If not... is there any chance that information sotred previously to > the problem could be lost/corrupted because sharding reallocation > between these multiple instances of ES? > > Thanks a lot for this great product, ---
**Author:** ![Frederic](https://avatars.discourse-cdn.com/v4/letter/f/4491bb/32.png) [@Frederic](https://discuss.elastic.co/u/Frederic)\ **Post date:** [November 21, 2011, 2:22pm UTC](https://discuss.elastic.co/t/running-more-than-one-es-instance-on-the-same-server-while-indexing-data/5913/3 "2011-11-21T14:22:48Z")
Hi Peter, Thanks for your help, and patiente too (my english is far from good 🙂 > How did you shut them down? one by one until cluster reached green? > E.g. if you shutdowntwoinstanceswhich havetworeplicas of a shard > (and you only havetwo) this shard cannot be reassigned ... Actually I shutted them all down, one by one (i.e. kill $PID), and restarted again one by one until status reached green. > yes, but not only on the same machine ... you can avoid that via the > cluster name yap, that makes sense > > If so, I understand that shutting down ES instances would act as if a > > node was stopped, regardless if some instances are running on the same server, correct? > > what do you mean here? sorry if it is not very clear. I just meant that if I have two ES instances running on the same machine, both part of the same cluster, and I shut down one of them, that would be the same as if I shut down an ES running on a different node. From your answers I think yes. > > If not... is there any chance that information sotred previously to the problem could be lost/corrupted because sharding > > reallocation between these multiple instances of ES? > > IMO no same for me and that's really great :¬) Thanks again Peter, Frederic ---
**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:** [November 22, 2011, 12:46pm UTC](https://discuss.elastic.co/t/running-more-than-one-es-instance-on-the-same-server-while-indexing-data/5913/4 "2011-11-22T12:46:02Z")
On Fri, Nov 18, 2011 at 10:03 PM, Frederic [focampo.br@gmail.com](mailto:focampo.br@gmail.com) wrote: > Hey guys, hope you can help me with this. > > By mistake, two instances of ES were launched (at the same 9200 port) > on al least 4 servers of a 8 nodes cluster. That happened while > multiple processes were indexing docs. > > After shutting down these extra instances and restarting the cluster, > the state was in RED as 2 shards were unassigned. Today I restarted > all nodes one by one and the cluster health got Green. > > From my tests on localhost, new ES instances running on the same > machine form a cluster like any other node and reallocate shards among > them, is this correct? Yes. Though you can disable allowing to run more than one node on a machine by setting node.max\_local\_storage\_nodes setting to 1. > If so, I understand that shutting down ES instances would act as if a > node was stopped, regardless if some instances are running on the same > server, correct? Yes. So, if you brought down the nodes one by one, and waited for green state between each shutdown, then all shards would end up migrated to the remaining nodes. > If not... is there any chance that information sotred previously to > the problem could be lost/corrupted because sharding reallocation > between these multiple instances of ES? > > Thanks a lot for this great product, ---
**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, 3:47am UTC](https://discuss.elastic.co/t/running-more-than-one-es-instance-on-the-same-server-while-indexing-data/5913/5 "2017-07-06T03:47:55Z")