Understanding clusters, replication, and sharding
Related to shard management, there is the key concept of replication and cluster status.
Getting ready
You need one or more nodes running to have a cluster. To test an effective cluster, you need at least two nodes (that can be on the same machine).
How it works...
An index can have one or more replicas; the shards are called primary if they are part of the primary replica, and secondary ones if they are part of replicas.
To maintain consistency in write operations, the following workflow is executed:
- The write operation is first executed in the primary shard
- If the primary write is successfully done, it is propagated simultaneously in all the secondary shards
- If a primary shard becomes unavailable, a ...
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