What are shards? How many shards should Elasticsearch indexes have?
Shards are the statements or smaller portion of the nodes which manage the data in an index. Actually, this indexing is done in order to overcome the limitations associated with the resources, especially like ram or CPU for the scalability. In order to resolve this, data is fragmented into different portions, which are administered by a different node or Elasticsearch. By default, the Elasticsearch index has 5 shards, which are primary and 1 replica. Thus, in total, each index has 10 shards.