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elasticsearchelasticsearch-6

How to add dedicated master node to existing elasticsearch cluster

We have 6 elasticsearch 6.4 with 3 of them are master eligible does both master and data node operations.

We are thinking of getting 3 dedicated Master as we see the 3 Master/Data node uses high resource utilization sometime and feel that it might crash during working hours some day.

Looking for procedure to add 3 new dedicated master server to existing cluster and how to make the current 3 Master/Data node to just data node.

Solution

  • We found our procedure on how to do this from below link.

    https://discuss.elastic.co/t/introduction-of-dedicated-master-nodes/43601

    We followed following steps (except disabling http port) mentioned in the post.

    • shutdown cluster
    • modify actual 5 nodes with master: false flag and data: true
    • make 3 new nodes master:true and data: false
    • modify all nodes to discover using 3 new master nodes addresses
    • we can optionnally disable http port on master nodes to make them not receiving REST requests.
    • start cluster

    We are still in experimental stage So full cluster restart is not an issue for us however the link has discussion about how to add dedicated master dynamically and avoid split brain issue.