Elasticsearch Replication

By Opster Team

Updated: Jan 28, 2024

| 1 min read


Replication refers to storing a redundant copy of the data. Starting from version 7.x, Elasticsearch creates one primary shard with a replication factor set to 1. Replicas never get assigned to the same node on which primary shards are assigned, which means you should have at least two nodes in the cluster to assign the replicas. If a primary shard goes down, the replica automatically acts as a primary shard.

What it is used for

Replicas are used to provide high availability and failover. A higher number of replicas is also helpful for faster searches.


Update replica count

PUT /api-logs/_settings?pretty
    "index" : {
        "number_of_replicas" : 2

Common problems

  • By default, new replicas are not assigned to nodes with more than 85% disk usage. Instead, Elasticsearch throws a warning.
  • Creating too many replicas may cause a problem if there are not enough resources available in the cluster. 

How helpful was this guide?

We are sorry that this post was not useful for you!

Let us improve this post!

Tell us how we can improve this post?

Related log errors to this ES concept

%s %s
Unexpected failure while failing primary primary routingEntry
Unexpected failure while failing primary
Actual Exception
Failed to perform on node
Unexpected error during the primary phase for action request
Unexpected error while failing replica
Unexpected error while replicating for action shard
Failed to perform
Failed to send error response for action
Unexpected error during the primary phase for action
Expected mapper parsing failures got

< Page: 1 of 2 >