Must all nodes of an Elasticsearch cluster be identical

clusterelasticsearch

In an Elasticsearch cluster, must all nodes be identical i.e. having the same:

  • Operating System
  • Amount of RAM
  • CPU speed and number of cores
  • etc.

or is it allowed for the nodes to be different? (Apart from the obvious fact that an homogeneous cluster would be much easier to configure, manage, and monitor than an heterogeneous one.)

Best Answer

It depends. They don't need to be identical in hardware resources. But they should be identical in OS (at least linux distribution or windows version) and must be identical in ES version.

ES doesn't support running multiple versions of ES in one cluster for long time because indices created or migrated on higher version cannot be migrated back to older version (due internal data mechanics and so on), so you will be in trouble when node with newer version will fail.

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