sh.startBalancer()¶

Definition定义¶

sh.startBalancer(timeout, interval)¶

Changed in version 4.2.在版本4.2中更改。

Starts the balancer in a sharded cluster. Starting in MongoDB 4.2, sh.startBalancer() also enables auto-splitting for the sharded cluster.

The method can take the following options:

Parameter参数	Type类型	Description描述
timeout	integer	Optional.可选。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.可选。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

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

Behavior行为¶

Starting in MongoDB 3.4, the mongo shell method sh.startBalancer() is a wrapper around the balancerStart command. As such, the method does not wait for balancing to start.

In earlier versions, the method waited for the balancing to start.