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sh.startBalancer() (mongosh method)

Definition

sh.startBalancer(timeout, interval)

Changed in version 7.0.

Starts the balancer in a sharded cluster.

Starting in MongoDB 7.0, starting the balancer also enables the AutoMerger for the sharded cluster.

Important

mongosh Method

This page documents a mongosh method. This is not the documentation for database commands or language-specific drivers, such as Node.js.

For the database command, see the balancerStart command.

For MongoDB API drivers, refer to the language-specific MongoDB driver documentation.

The method can take the following options:

Parameter	Type	Description
`timeout`	integer	Optional. Time limit for enabling the balancer. Defaults to 60000 milliseconds.
`interval`	integer	Optional. The frequency (in milliseconds) at which to check if a balancing round has started.

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

Compatibility

This method is available in deployments hosted in the following environments:

MongoDB Atlas: The fully managed service for MongoDB deployments in the cloud

Important

This command is not supported in M0 and Flex clusters. For more information, see Unsupported Commands.

MongoDB Enterprise: The subscription-based, self-managed version of MongoDB
MongoDB Community: The source-available, free-to-use, and self-managed version of MongoDB

Behavior

The mongosh shell method sh.startBalancer() is a wrapper around the balancerStart command. sh.startBalancer() runs the balancerStart command in the background and returns immediately.

Learn More

To learn how to configure the balancer for your cluster, see Manage Sharded Cluster Balancer.

To disable balancing for a specific collection, see Disable Balancing on a Collection.

To re-enable balancing on a specific collection, see Enable Balancing on a Collection.

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sh.startAutoMerger

sh.status