# Elasticsearch cluster automatic master

**URL:** <https://discuss.elastic.co/t/elasticsearch-cluster-automatic-master/79028>\
**Category:** Elasticsearch\
**Created:** [March 17, 2017, 1:06pm UTC](https://discuss.elastic.co/t/elasticsearch-cluster-automatic-master/79028 "2017-03-17T13:06:26Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Exocomp](https://avatars.discourse-cdn.com/v4/letter/e/ea5d25/32.png) [@Exocomp](https://discuss.elastic.co/u/Exocomp)\
**Post date:** [March 17, 2017, 1:06pm UTC](https://discuss.elastic.co/t/elasticsearch-cluster-automatic-master/79028/1 "2017-03-17T13:06:26Z")

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Hi,

Currently I have a single instance of elasticsearch and would like to setup an elasticsearch cluster to increase availability and throughput. I've done some research and would appreciate if someone could confirm my understand and answer the one question I have.

I want a 3 node cluster:

- 1 as _master only_
- 2 as _master+data_

With this setup ideally _master only_ will do the "administrative" work and the 2 _master+data_ will be available for CRUD operations.

However, in case _master only_ goes down then 1 of the two _master+data_ will _automatically_ be master for the time being.

My question is, when the _master only_ node becomes available again will the cluster _automatically_ make it the master again even though there is already a _master+data_ node as master ? Or do I have to manually make the _master only_ node master again in that scenario ?

Thanks,  
E

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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:** [March 17, 2017, 1:29pm UTC](https://discuss.elastic.co/t/elasticsearch-cluster-automatic-master/79028/2 "2017-03-17T13:29:17Z")

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> [@Exocomp](#):
>
> when the master only node becomes available again will the cluster automatically make it the master again even though there is already a master+data node as master ?

No.

I don't think there is any API BTW which does that but I might be wrong. Others can comment.  
I believe this is the intention of this demand:

> <https://github.com/elastic/elasticsearch/issues/10793>
>
> It would be nice to add dedicated master nodes to an existing cluster without re…quiring a full restart of each node in the cluster. To accomplish this, the \`node.master\` would need to be dynamically configurable.
> 
> Changing the \`node.master\` setting at runtime would \*\*not\*\* force a new master election. It would only apply to the cluster moving forward. To force a master election, the current master node would need to be restarted as is currently the case today.

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<div class="post-metadata">

**Author:** ![Exocomp](https://avatars.discourse-cdn.com/v4/letter/e/ea5d25/32.png) [@Exocomp](https://discuss.elastic.co/u/Exocomp)\
**Post date:** [March 17, 2017, 2:23pm UTC](https://discuss.elastic.co/t/elasticsearch-cluster-automatic-master/79028/3 "2017-03-17T14:23:39Z")

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@dadoonet thanks, although not what I wanted to hear. Was hoping to avoid manually getting things back in order.

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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:** [April 14, 2017, 2:24pm UTC](https://discuss.elastic.co/t/elasticsearch-cluster-automatic-master/79028/4 "2017-04-14T14:24:10Z")

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