The update() method returns an object that contains the status of the operation.

MongoDB provides no method to deactivate sharding for a collection after calling shardCollection.

The sh._lastMigration() method returns a document with details about the last migration performed on the database or collection.

For a sharded collection, mergeChunks combines contiguous chunk ranges on a shard into a single chunk.

The balancer is a background process that manages chunk migrations.

sh.splitFind() creates two roughly equal chunks.

Sharding partitions a collection's data by the shard key.

You may delete tag assignment from a shard key range by removing the corresponding document from the tags collection of the config database.

When the primary steps down, the mongod closes all client connections.

During the migration process, operations to the chunk route to the source shard.