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sh.startBalancer(timeout, interval)

Starts the balancer in a sharded cluster.


You can only run sh.startBalancer() on a mongos instance. sh.startBalancer() errors if run on mongod instance.

Changed in version 3.4: Beginning in MongoDB 3.4, the method does not wait for balancing to start. In earlier versions, the method waited for the balancing to initiate.

Parameter Type Description
timeout integer

Optional. Time limit for enabling the balancer.

Defaults to 60000 milliseconds.

Changed in version 3.4: If using the 3.4 mongo shell with earlier version sharded clusters, the parameter specifies the amount of time to wait for the balancing round to start.

interval integer

Optional. The frequency (in milliseconds) at which to check if a balancing round has started.

Changed in version 3.4: Only applicable when using version 3.4 mongo shell with earlier version sharded clusters.s

The mongo shell method sh.startBalancer is a wrapper around the balancerStart command, introduced in 3.4.