In order to maintain an optimal set of open connections while serving an nss/cluster.watch() request, mongos must be notified of any event that modifies the current data placement of the nss/cluster being targeted through the emission of an oplog event.

As per today, the following Sharding DDL operations do not emit any information when committed:

• addShard(connString, shardName)
• enableSharding(dbName)
• movePrimary(dbName, destinationShard)

The objective of this ticket is defining a new oplog entry type for each aforementioned command. (Separate tickets will be created to also implement the logic to emit them).