# Unexpected cluster behavior **URL:** \ **Category:** Elasticsearch\ **Created:** [May 30, 2012, 12:53pm UTC](https://discuss.elastic.co/t/unexpected-cluster-behavior/7910 "2012-05-30T12:53:28Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![Andrej](https://avatars.discourse-cdn.com/v4/letter/a/d9b06d/32.png) [@Andrej](https://discuss.elastic.co/u/Andrej)\ **Post date:** [May 30, 2012, 12:53pm UTC](https://discuss.elastic.co/t/unexpected-cluster-behavior/7910/1 "2012-05-30T12:53:28Z")
Hi all, we noticed a very strange behavior of our cluster last night (16 nodes, all running 0.19.4). At a certain time one cluster node obviously restarted (at least I would interpret the log message "[2012-05-29 23:33:44,090][INFO][node] [Star- Lord] {0.19.4}[23335]: starting ... " this way). Within the next half hour another 5 nodes restarted, some of them several (up to 4) times. In the logs we couldnt find anything like stopping or stopped, what is the usual output when stopping a node. My questions: - is it possible to start a node that wasnt stopped before? - what can actually start an elasticsearch node? At this time we didnt use the index, so no requests were sent from our side. Can elasticsearch itself restart nodes and if so, what triggers this? - finally, after restarting no indices were found. Any ideas on this one? Shay, if you are interested in more information I can send you all logs. The beer in Berlin is on me 😉 Thanks! Andrej ---
**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:** [June 3, 2012, 9:08am UTC](https://discuss.elastic.co/t/unexpected-cluster-behavior/7910/2 "2012-06-03T09:08:38Z")
Can you share the logs, that would be helpful? When a node shuts down properly (i.e., sending a kill command (without -9)), or using the shutdown API, it will log the fact that its stopping. Obviously, nodes can't start by themselves unless they are being run by another demon. Are you using something like that? The service wrapper maybe? On Wed, May 30, 2012 at 2:53 PM, Andrej Rosenheinrich \< [andrej.rosenheinrich@unister.de](mailto:andrej.rosenheinrich@unister.de)\> wrote: > Hi all, > > we noticed a very strange behavior of our cluster last night (16 > nodes, all running 0.19.4). At a certain time one cluster node > obviously restarted (at least I would interpret the log message > "[2012-05-29 23:33:44,090][INFO][node] [Star- > Lord] {0.19.4}[23335]: starting ... " this way). Within the next half > hour another 5 nodes restarted, some of them several (up to 4) times. > In the logs we couldnt find anything like stopping or stopped, what is > the usual output when stopping a node. > > My questions: > > - is it possible to start a node that wasnt stopped before? > - what can actually start an elasticsearch node? At this time we didnt > use the index, so no requests were sent from our side. Can > elasticsearch itself restart nodes and if so, what triggers this? > - finally, after restarting no indices were found. Any ideas on this > one? > > Shay, if you are interested in more information I can send you all > logs. The beer in Berlin is on me 😉 > > Thanks! > Andrej ---
**Author:** ![Andrej](https://avatars.discourse-cdn.com/v4/letter/a/d9b06d/32.png) [@Andrej](https://discuss.elastic.co/u/Andrej)\ **Post date:** [June 6, 2012, 2:38pm UTC](https://discuss.elastic.co/t/unexpected-cluster-behavior/7910/3 "2012-06-06T14:38:12Z")
Shay, your hint was absolutely the right one, reading the logs from the service wrapper revealed that the wrapper decided to restart the JVM because it did not responded the expected way. So at least we have an explanation, I can sleep well again 😉 It was nice to talk to you in Berlin, thanks for your informations and your interesting talk. Cant wait to try out 0.19.5 😉 Greets, Andrej ---
**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, 3:25am UTC](https://discuss.elastic.co/t/unexpected-cluster-behavior/7910/4 "2017-07-06T03:25:26Z")