configureCollectionBalancing

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Definition

Syntax
Examples

Definition

configureCollectionBalancing: New in version 5.3.
Configures balancer settings for a sharded collection, such as setting the chunk size for and defragmenting the collection.

Syntax

The command has the following syntax:

db.adminCommand(
   {
     configureCollectionBalancing: "<collection>",
     chunkSize: <num>,
     defragmentCollection: <bool>
   }
)

Command Fields

configureCollectionBalancing has the following fields:

Field	Type	Description
`configureCollectionBalancing`	string	Required: The name of the database and sharded collection to configure.
`chunkSize`	integer	Optional: Sets the chunk size in MiB for the collection. The recommended size is 256, 512, or larger.
`defragmentCollection`	boolean	Optional: Causes the balancer to defragment the collection.

For more information, see Data Partitioning with Chunks.

Examples

Configure Chunk Size

To change the chunk size for a sharded collection, use the chunkSize option:

db.adminCommand( {
   configureCollectionBalancing: "test.students",
   chunkSize: 256
} )

Use this command to change the chunk size for the given collection.

Warning

By default, MongoDB cannot move a chunk if the number of documents in the chunk is greater than 1.3 times the result of dividing the configured chunk size by the average document size.

To find the average document size, see the avgObjSize field in the output of the db.collection.stats() method.

For more information, see Chunk Size.

Defragment Collections

To tell the balancer to defragment a sharded collection, use the defragmentCollection option:

db.adminCommand( {
   configureCollectionBalancing: "test.students",
   defragmentCollection: true
} )

Use this command to have the balancer defragment a sharded collection.

Reconfigure and Defragment Collections

To defragment a sharded collection while updating the chunk size, use the defragmentCollection option and the chunkSize option together:

db.adminCommand( {
   configureCollectionBalancing: "test.students",
   chunkSize: 512,
   defragmentCollection: true
} )

← commitReshardCollection enableSharding →