# Split Brain Scenario

**URL:** <https://discuss.elastic.co/t/split-brain-scenario/180658>\
**Category:** Elasticsearch\
**Created:** [May 11, 2019, 3:53pm UTC](https://discuss.elastic.co/t/split-brain-scenario/180658 "2019-05-11T15:53:16Z")\
**Posts on this page:** 8\
**Page:** 1

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**Author:** ![Ganesh999](https://avatars.discourse-cdn.com/v4/letter/g/a88e4f/32.png) [@Ganesh999](https://discuss.elastic.co/u/Ganesh999)\
**Post date:** [May 11, 2019, 3:53pm UTC](https://discuss.elastic.co/t/split-brain-scenario/180658/1 "2019-05-11T15:53:16Z")

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Hi,

We currently experienced split brain scenario in elasticsearch. After it happened we reseted the cluster setting and added that node to the cluster and did the required setting like master eligible node to 3 and minimum zen master node to 2.  
But after adding there are shards that are not assigned both the shards like primary and replica for certain index are not getting assigned and shoes the cluster health is red.  
How to recover from this issue. Plz help me out?

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**Author:** ![Christian\_Dahlqvist](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/christian_dahlqvist/32/4617_2.png) [@Christian\_Dahlqvist](https://discuss.elastic.co/u/Christian_Dahlqvist)\
**Post date:** [May 11, 2019, 4:43pm UTC](https://discuss.elastic.co/t/split-brain-scenario/180658/2 "2019-05-11T16:43:45Z")

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Which version are you on? How many nodes in the cluster? How many indices and shards in the cluster? How much data do these hold? How many indices are red?

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**Author:** ![Ganesh999](https://avatars.discourse-cdn.com/v4/letter/g/a88e4f/32.png) [@Ganesh999](https://discuss.elastic.co/u/Ganesh999)\
**Post date:** [May 12, 2019, 3:04am UTC](https://discuss.elastic.co/t/split-brain-scenario/180658/3 "2019-05-12T03:04:40Z")

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Elasticsearch version 6.3.1  
5 nodes - for now all 5 nodes are data node and 3 are master we will have dedicated master soon  
There are 380 indices with 4200 shards

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**Author:** ![dadoonet](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/dadoonet/32/137187_2.png) [@dadoonet](https://discuss.elastic.co/u/dadoonet)\
**Post date:** [May 12, 2019, 7:46am UTC](https://discuss.elastic.co/t/split-brain-scenario/180658/4 "2019-05-12T07:46:56Z")

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It's 840 shards per node.  
That's a way too much IMO.

How much memory do you have?

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**Author:** ![Ganesh999](https://avatars.discourse-cdn.com/v4/letter/g/a88e4f/32.png) [@Ganesh999](https://discuss.elastic.co/u/Ganesh999)\
**Post date:** [May 12, 2019, 11:03am UTC](https://discuss.elastic.co/t/split-brain-scenario/180658/5 "2019-05-12T11:03:27Z")

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Each node has 16 GB of memory but for elasticsearch we have assigned 6 GB of memory

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**Author:** ![dadoonet](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/dadoonet/32/137187_2.png) [@dadoonet](https://discuss.elastic.co/u/dadoonet)\
**Post date:** [May 12, 2019, 11:22pm UTC](https://discuss.elastic.co/t/split-brain-scenario/180658/6 "2019-05-12T23:22:58Z")

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At most, 120 shards per node then.

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<div class="post-metadata">

**Author:** ![Ganesh999](https://avatars.discourse-cdn.com/v4/letter/g/a88e4f/32.png) [@Ganesh999](https://discuss.elastic.co/u/Ganesh999)\
**Post date:** [May 13, 2019, 4:17am UTC](https://discuss.elastic.co/t/split-brain-scenario/180658/7 "2019-05-13T04:17:04Z")

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Is there a way to recover the shards both the replica and primary are unassigned

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**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\
**Post date:** [June 10, 2019, 4:17am UTC](https://discuss.elastic.co/t/split-brain-scenario/180658/8 "2019-06-10T04:17:08Z")

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