# How can I change an existing node with both "master" and "data" roles to be a "master" role only, without any downtime?

**URL:** <https://discuss.elastic.co/t/how-can-i-change-an-existing-node-with-both-master-and-data-roles-to-be-a-master-role-only-without-any-downtime/340526>\
**Category:** Elasticsearch\
**Created:** [August 10, 2023, 8:26am UTC](https://discuss.elastic.co/t/how-can-i-change-an-existing-node-with-both-master-and-data-roles-to-be-a-master-role-only-without-any-downtime/340526 "2023-08-10T08:26:07Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Manal\_A](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/manal_a/32/123992_2.png) [@Manal\_A](https://discuss.elastic.co/u/Manal_A)\
**Post date:** [August 10, 2023, 8:26am UTC](https://discuss.elastic.co/t/how-can-i-change-an-existing-node-with-both-master-and-data-roles-to-be-a-master-role-only-without-any-downtime/340526/1 "2023-08-10T08:26:07Z")

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I have a cluster with multiple nodes. I intend to dynamically change an existing node that currently serves both the "master" and "data" roles to exclusively perform the "data" role, all without causing any downtime. What would be the optimal approach to achieve this?

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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:** [August 10, 2023, 8:28am UTC](https://discuss.elastic.co/t/how-can-i-change-an-existing-node-with-both-master-and-data-roles-to-be-a-master-role-only-without-any-downtime/340526/2 "2023-08-10T08:28:45Z")

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Assuming you have the recommended 3 master eligible nodes, which is required for you to be able to handle one node going down without the cluster going into red state, you could just restart it with new settings assuming you have vacated all shards. If you do not have 3 master eligible nodes I would recommend fixing this before making this change.

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**Author:** ![Manal\_A](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/manal_a/32/123992_2.png) [@Manal\_A](https://discuss.elastic.co/u/Manal_A)\
**Post date:** [August 24, 2023, 8:53am UTC](https://discuss.elastic.co/t/how-can-i-change-an-existing-node-with-both-master-and-data-roles-to-be-a-master-role-only-without-any-downtime/340526/3 "2023-08-24T08:53:16Z")

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Will there be any desynchronization during the data node restart?

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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:** [September 21, 2023, 8:54am UTC](https://discuss.elastic.co/t/how-can-i-change-an-existing-node-with-both-master-and-data-roles-to-be-a-master-role-only-without-any-downtime/340526/4 "2023-09-21T08:54:06Z")

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