sh.addShard()

Definition

  • sh.addShard()
  • Adds a shard replica set to a sharded cluster. This methodmust be run on a mongos instance.

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

ParameterTypeDescriptionhoststringThe replica set name, hostname, and port of at least one member ofthe shard’s replica set. Any additional replica set member hostnamesmust be comma separated. For example:

  1. <replica_set>/<hostname><:port>,<hostname><:port>, ...

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

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

Warning

Do not use localhost for the hostname unless yourconfig serveris also running on localhost.

New in version 2.6: mongos installed from official .deb and .rpm packageshave the bind_ip configuration set to 127.0.0.1 bydefault.

mongos uses"majority" for theaddShard command and its helpersh.addShard().

The sh.addShard() method is a helper for theaddShard command. The addShard command hasadditional options which are not available with this helper.

Considerations

Balancing

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

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

Hidden Members

Important

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

Example

To add a shard, specify the name of the replica set andthe hostname of at least one member of the replica set, as a seed. Ifyou specify additional hostnames, all must be members of the samereplica set.

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

  1. sh.addShard("repl0/mongodb3.example.net:27327")