I am changing the index configurations on replica cluster in a database, but re-indexing is not getting triggered automatically whereas I have set the "reindexer enable" to "true".
Any thoughts around this?
In order to re-index the replica you have to re-index the master. You do this by adding the new index information to the replica first and then add it to the master. Once its added to the master reindexing should happen automatically. If it doesn't make sure you have re-indexing set to true on the master.
Check out this article from more information https://help.marklogic.com/knowledgebase/article/View/43/19/database-replication-indexing-on-replica-explained
In a database replication setup, it is necessary to apply index changes on the replica first and then apply them on the master. You will need to do a forced re-indexing on the master to get the replica into a consistent state with the index changes.
There is an explanation here: http://docs.marklogic.com/guide/concepts/backup-replication#id_27654
Also see: http://docs.marklogic.com/guide/database-replication/dbrep_intro#id_27654