What is REPLICAS in Elasticsearch?
As Elasticsearch is a full-text distributed search engine, each index in it splits to multiple forms. It comprises five shards and one replica for each specific index. Replica serves the queries as requests, and each of them corresponds to the primary shared in the cluster. When the index is created the number of replicas per index can be defined. They exist in order to provide availability and fault tolerance.
BY Best Interview Question ON 04 Jun 2019