rs.addArb() (original) (raw)

rs.addArb(host)

Adds a new arbiter to an existing replica set.

rs.add(<host>, true) is functionally the same asrs.addArb(<host>). You can use these commands interchangeably.

Warning

To add an arbiter to an existing replica set:

• Typically, if there are two or fewer data-bearing members in the replica set, you might need to first set the cluster wide write concern for the replica set.
• See cluster wide write concern for more information on why you might need to set the cluster wide write concern.

You do not need to change the cluster wide write concern before starting a new replica set with an arbiter.

See also:

The rs.addArb() method takes the following parameter:

This method is available in deployments hosted in the following environments:

• MongoDB Enterprise: The subscription-based, self-managed version of MongoDB
• MongoDB Community: The source-available, free-to-use, and self-managed version of MongoDB

Warning

MongoDB binaries, mongod and mongos, bind to localhost by default. If the net.ipv6 configuration file setting or the --ipv6 command line option is set for the binary, the binary additionally binds to the localhost IPv6 address.

By default mongod and mongos that are bound to localhost only accept connections from clients that are running on the same computer. This binding behavior includesmongosh and other members of your replica set or sharded cluster. Remote clients cannot connect to binaries that are bound only to localhost.

To override the default binding and bind to other IP addresses, use thenet.bindIp configuration file setting or the --bind_ipcommand-line option to specify a list of hostnames or IP addresses.

Warning

For example, the following mongod instance binds to both the localhost and the hostname My-Example-Associated-Hostname, which is associated with the IP address 198.51.100.1:

mongod --bind_ip localhost,My-Example-Associated-Hostname

In order to connect to this instance, remote clients must specify the hostname or its associated IP address 198.51.100.1:

mongosh --host My-Example-Associated-Hostname

mongosh --host 198.51.100.1

Important

To avoid configuration updates due to IP address changes, use DNS hostnames instead of IP addresses. It is particularly important to use a DNS hostname instead of an IP address when configuring replica set members or sharded cluster members.

Use hostnames instead of IP addresses to configure clusters across a split network horizon. Starting in MongoDB 5.0, nodes that are only configured with an IP address fail startup validation and do not start.