# Elasticsearch

**URL:** <https://discuss.elastic.co/t/elasticsearch/269615>\
**Category:** Elasticsearch\
**Created:** [April 8, 2021, 3:03pm UTC](https://discuss.elastic.co/t/elasticsearch/269615 "2021-04-08T15:03:17Z")\
**Posts on this page:** 9\
**Page:** 1

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**Author:** ![dddddddddddddddd](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/dddddddddddddddd/32/86746_2.png) [@dddddddddddddddd](https://discuss.elastic.co/u/dddddddddddddddd)\
**Post date:** [April 8, 2021, 3:03pm UTC](https://discuss.elastic.co/t/elasticsearch/269615/1 "2021-04-08T15:03:17Z")

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hi  
good day eveyone , why do we need 3 nodes in elasticsearch cluster for guarantee the high availibility and disaster recovery

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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:** [April 8, 2021, 3:06pm UTC](https://discuss.elastic.co/t/elasticsearch/269615/2 "2021-04-08T15:06:08Z")

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Master election is based on majority decisions and only when you have 3 nodes or more can you form a strict majority without ALL nodes present. This allows a master to be elected even if one of the nodes is down.

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**Author:** ![dddddddddddddddd](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/dddddddddddddddd/32/86746_2.png) [@dddddddddddddddd](https://discuss.elastic.co/u/dddddddddddddddd)\
**Post date:** [April 8, 2021, 3:15pm UTC](https://discuss.elastic.co/t/elasticsearch/269615/3 "2021-04-08T15:15:31Z")

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so if one of nodes is down the other node can elect another master right?

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<div class="post-metadata">

**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:** [April 8, 2021, 3:29pm UTC](https://discuss.elastic.co/t/elasticsearch/269615/4 "2021-04-08T15:29:18Z")

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Yes, the other 2 nodes can form a majority and elect the master.

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**Author:** ![dddddddddddddddd](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/dddddddddddddddd/32/86746_2.png) [@dddddddddddddddd](https://discuss.elastic.co/u/dddddddddddddddd)\
**Post date:** [April 8, 2021, 3:57pm UTC](https://discuss.elastic.co/t/elasticsearch/269615/5 "2021-04-08T15:57:09Z")

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So, for example, if we have two nodes and one of them is disabled, could the remaining node elect itself?

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<div class="post-metadata">

**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:** [April 8, 2021, 4:12pm UTC](https://discuss.elastic.co/t/elasticsearch/269615/6 "2021-04-08T16:12:36Z")

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No. The strict majority of 2 is 2, so both nodes are needed to elect a master. That is why 3 is the minimum.

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<div class="post-metadata">

**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:** [April 8, 2021, 4:53pm UTC](https://discuss.elastic.co/t/elasticsearch/269615/8 "2021-04-08T16:53:09Z")

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If any node goes down the remaining nodes will verify they can form a majority and elect a master if necessary.

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<div class="post-metadata">

**Author:** ![dddddddddddddddd](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/dddddddddddddddd/32/86746_2.png) [@dddddddddddddddd](https://discuss.elastic.co/u/dddddddddddddddd)\
**Post date:** [April 9, 2021, 8:23am UTC](https://discuss.elastic.co/t/elasticsearch/269615/9 "2021-04-09T08:23:09Z")

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thank you very much

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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:** [May 7, 2021, 8:23am UTC](https://discuss.elastic.co/t/elasticsearch/269615/10 "2021-05-07T08:23:45Z")

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