# Elasticsearch master node times out during cluster recovery stage due to heavy GC **URL:** \ **Category:** Elasticsearch\ **Created:** [June 12, 2014, 10:54pm UTC](https://discuss.elastic.co/t/elasticsearch-master-node-times-out-during-cluster-recovery-stage-due-to-heavy-gc/18080 "2014-06-12T22:54:01Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![hrishikesh\_prabhune](https://avatars.discourse-cdn.com/v4/letter/h/6f9a4e/32.png) [@hrishikesh\_prabhune](https://discuss.elastic.co/u/hrishikesh_prabhune)\ **Post date:** [June 12, 2014, 10:54pm UTC](https://discuss.elastic.co/t/elasticsearch-master-node-times-out-during-cluster-recovery-stage-due-to-heavy-gc/18080/1 "2014-06-12T22:54:01Z")
I have a huge elasticsearch cluster with 18 nodes each having a jvm heap size of 25gb. The cluster holds total of 182 timestamped indices. Each index has approximately 1500 aliases. Whenever I do a full cluster restart the master node goes into massive garbage collection and is not able to recover indices into the cluster state. As a result the cluster state shows: "cluster\_name" : "ES\_cluster", "status" : "red", "timed\_out" : false, "number\_of\_nodes" : 18, "number\_of\_data\_nodes" : 18, "active\_primary\_shards" : 0, "active\_shards" : 0, "relocating\_shards" : 0, "initializing\_shards" : 0, "unassigned\_shards" : 0 After sometime the ping timeouts kicks in and the master node is dropped from the cluster and is unable to rejoin it again. After it has dropped from the cluster a new master is elected and then it also goes into massive garbage collection. It seems that too many aliases are causing the cluster state to explode. I think my problem is similar to this question: [http://elasticsearch-users.115913.n3.nabble.com/Multiple-cluster-state-copies-in-memory-VS-many-aliases-td4046417.html](http://elasticsearch-users.115913.n3.nabble.com/Multiple-cluster-state-copies-in-memory-VS-many-aliases-td4046417.html) I am using ES version : 1.2.1 , Java version : 1.8.0\_05 Does anyone know how to get around the 'too many aliases' problem without deleting the aliases? Thanks in advance! -- 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/072f84f1-f12d-42ab-809d-8a7d578be18d%40googlegroups.com](https://groups.google.com/d/msgid/elasticsearch/072f84f1-f12d-42ab-809d-8a7d578be18d%40googlegroups.com). For more options, visit [https://groups.google.com/d/optout](https://groups.google.com/d/optout). ---
**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 15, 2014, 10:56pm UTC](https://discuss.elastic.co/t/elasticsearch-master-node-times-out-during-cluster-recovery-stage-due-to-heavy-gc/18080/2 "2014-06-15T22:56:45Z")
Heya, I tried to simulate what you are having, and there is a quick fix that makes a big difference, see more here: [Better default size for global index -\> alias map by kimchy · Pull Request #6504 · elastic/elasticsearch · GitHub](https://github.com/elasticsearch/elasticsearch/pull/6504). There are additional optimizations that we can make, but those will be a bit more complex. On Jun 13, 2014, at 0:54, hrishikesh prabhune [hruship@gmail.com](mailto:hruship@gmail.com) wrote: > I have a huge elasticsearch cluster with 18 nodes each having a jvm heap size of 25gb. The cluster holds total of 182 timestamped indices. Each index has approximately 1500 aliases. > Whenever I do a full cluster restart the master node goes into massive garbage collection and is not able to recover indices into the cluster state. As a result the cluster state shows: > "cluster\_name" : "ES\_cluster", > "status" : "red", > "timed\_out" : false, > "number\_of\_nodes" : 18, > "number\_of\_data\_nodes" : 18, > "active\_primary\_shards" : 0, > "active\_shards" : 0, > "relocating\_shards" : 0, > "initializing\_shards" : 0, > "unassigned\_shards" : 0 > > After sometime the ping timeouts kicks in and the master node is dropped from the cluster and is unable to rejoin it again. After it has dropped from the cluster a new master is elected and then it also goes into massive garbage collection. It seems that too many aliases are causing the cluster state to explode. > I think my problem is similar to this question: > [http://elasticsearch-users.115913.n3.nabble.com/Multiple-cluster-state-copies-in-memory-VS-many-aliases-td4046417.html](http://elasticsearch-users.115913.n3.nabble.com/Multiple-cluster-state-copies-in-memory-VS-many-aliases-td4046417.html) > > I am using ES version : 1.2.1 , Java version : 1.8.0\_05 > > Does anyone know how to get around the 'too many aliases' problem without deleting the aliases? > > Thanks in advance! > > -- > 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/072f84f1-f12d-42ab-809d-8a7d578be18d%40googlegroups.com](https://groups.google.com/d/msgid/elasticsearch/072f84f1-f12d-42ab-809d-8a7d578be18d%40googlegroups.com). > 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/7DA18C18-42F5-4977-8052-8F7C9DBA7024%40gmail.com](https://groups.google.com/d/msgid/elasticsearch/7DA18C18-42F5-4977-8052-8F7C9DBA7024%40gmail.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, 1:22am UTC](https://discuss.elastic.co/t/elasticsearch-master-node-times-out-during-cluster-recovery-stage-due-to-heavy-gc/18080/3 "2017-07-06T01:22:21Z")