sh.addShard()

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Definition

sh. addShard ( <url> )

Adds a shard replica set to a sharded cluster. This method must be run on a mongos instance.

The sh.addShard() method has the following parameter:

Parameter	Type	Description
`host`	string	The replica set name, hostname, and port of at least one member of the shard’s replica set. Any additional replica set member hostnames must be comma separated. For example: copy `<replica_set>/<hostname><:port>,<hostname><:port>, ...`

The sh.addShard() method has the following prototype form:

copy

sh.addShard("<replica_set>/<hostname><:port>")

Warning

Do not use localhost for the hostname unless your config server is also running on localhost.

New in version 2.6: mongos installed from official .deb and .rpm packages have the bind_ip configuration set to 127.0.0.1 by default.

The sh.addShard() method is a helper for the addShard command. The addShard command has additional options which are not available with this helper.

Considerations

Balancing

When you add a shard to a sharded cluster, you affect the balance of chunks among the shards of a cluster for all existing sharded collections. The balancer will begin migrating chunks so that the cluster will achieve balance. See Cluster Balancer for more information.

Changed in version 2.6: Chunk migrations can have an impact on disk space. Starting in MongoDB 2.6, the source shard automatically archives the migrated documents by default. For details, see moveChunk directory.

Hidden Members

Important

You cannot include a hidden member in the seed list provided to sh.addShard().

Example

To add a shard, specify the name of the replica set and the hostname of at least one member of the replica set, as a seed. If you specify additional hostnames, all must be members of the same replica set.

The following example adds a replica set named repl0 and specifies one member of the replica set: