# Master node writes to only one data node use case

**URL:** <https://discuss.elastic.co/t/master-node-writes-to-only-one-data-node-use-case/223061>\
**Category:** Elasticsearch\
**Created:** [March 11, 2020, 7:22am UTC](https://discuss.elastic.co/t/master-node-writes-to-only-one-data-node-use-case/223061 "2020-03-11T07:22:39Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![RAM\_NATHAN](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/ram_nathan/32/50393_2.png) [@RAM\_NATHAN](https://discuss.elastic.co/u/RAM_NATHAN)\
**Post date:** [March 11, 2020, 7:22am UTC](https://discuss.elastic.co/t/master-node-writes-to-only-one-data-node-use-case/223061/1 "2020-03-11T07:22:39Z")

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Hi

I'm having three nodes one acts as master and two as data nodes. I need to ensure high availability. I want master to write data only to one node, say node A and other node will be only read-only node, node B. But if node A goes down, I prefer node B to be changed to write node and get the data, till node A comes up.  
Ideally I need my data to be written to one node, which is active

Is it possible???

Regards  
Ram

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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:** [March 11, 2020, 7:52am UTC](https://discuss.elastic.co/t/master-node-writes-to-only-one-data-node-use-case/223061/2 "2020-03-11T07:52:03Z")

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Elasticsearch does not work that way. If you want high availability you need to make all nodes master eligible as a minimum of 3 master eligible nodes is required. If you are on a version prior to 7.x you also need to set minimum\_master\_nodes to 2. Then make sure all indices have one replica configured and Elasticsearch will take care of the rest. You can read and write to any data node.

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<div class="post-metadata">

**Author:** ![RAM\_NATHAN](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/ram_nathan/32/50393_2.png) [@RAM\_NATHAN](https://discuss.elastic.co/u/RAM_NATHAN)\
**Post date:** [March 11, 2020, 9:03am UTC](https://discuss.elastic.co/t/master-node-writes-to-only-one-data-node-use-case/223061/3 "2020-03-11T09:03:28Z")

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In that case, whether data will be spread across nodes?? means should I worry that fallen node data will not be visible in kibana??

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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 9, 2020, 9:41am UTC](https://discuss.elastic.co/t/master-node-writes-to-only-one-data-node-use-case/223061/5 "2020-04-09T09:41:08Z")

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