sh.moveChunk()

Definition

sh.moveChunk(namespace, query, destination)

Moves the chunk that contains the document specified by the query to the destination shard. sh.moveChunk() provides a wrapper around the moveChunk database command.

Important

In most circumstances, allow the balancer to automatically migrate chunks, and avoid calling sh.moveChunk() directly.

Warning

This command cannot be used for hashed shard keys, as it uses the find option from the moveChunk command. To move a chunk with a hashed shard key, use the moveChunk command specifying the bounds field.

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 moveChunk command.

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

For the legacy mongo shell documentation, refer to the documentation for the corresponding MongoDB Server release:

• mongo shell v4.4

• mongo shell v4.2

sh.moveChunk() takes the following arguments:

Parameter	Type	Description
namespace	string	The namespace of the sharded collection that contains the chunk to migrate.
query	document	An equality match on the shard key that selects the chunk to move.
destination	string	The name of the shard to move.

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. Starting in MongoDB 4.4, the moveChunk command can specify a new option forceJumbo to allow for the manual migration of chunks too large to move, with or without the jumbo label. See moveChunk command for details.

Example

Given the people collection in the records database, the following operation finds the chunk that contains the documents with the zipcode field set to 53187 and then moves that chunk to the shard named shard0019:

sh.moveChunk("records.people", { zipcode: "53187" }, "shard0019")