CODEWITHSUNDEEP
elasticsearch
Geoffrey Samper
Geoffrey Samper

Reputation: 497

From how many nodes do you need dedicated master nodes

A question. Is there any recommandation from how many nodes that you need to use dedicated master nodes in a elasticsearch cluster?

My setup:

Does the master nodes need the same memory requirement as the data nodes?

Upvotes: 0

Views: 1835

Answers (1)

Vova Bilyachat
Vova Bilyachat

Reputation: 19504

At a time you can have only one master node, but for availability you should have more than one master elegible by setting node.master

The master node is the only node in a cluster that can make changes to the cluster state. This mean that if your master node is rebooted or down then you will not be able to make any changes to your cluster.

Well at some point it is a bit hard to what is right or best practice because it always depends on many parameters.

With your setup i would better go with 3 nodes and up to 64 GB of memory per each node, other wise you are loosing some hits on communication between your 7 servers while they are not utilizing 100% of resources. Then all 3 nodes must be able to become master and set 

discovery.zen.minimum_master_nodes: 2

This parameter is a bit important to avoid brain split when each node could become a master.

For you critical data you must use 1 replica to prevent lose of data.

Other option would be to make master only nodes and data only nodes.

So at some point minimum master nodes should be always 3 this will allow you to upgrade without downtime and make sure that you have always on setup.

Upvotes: 0

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