addArb( host )
Adds a new arbiter to an existing replica set.
In general, avoid deploying more than one arbiter per replica set.
rs.addArb()method takes the following parameter:
Parameter Type Description
string Specifies the hostname and optionally the port number of the arbiter member to add to replica set.
For the following MongoDB versions,
pv1increases the likelihood of
w:1rollbacks compared to
pv0for replica sets with arbiters:
- MongoDB 3.4.1
- MongoDB 3.4.0
- MongoDB 3.2.11 or earlier
Starting in MongoDB 3.6, MongoDB binaries,
mongos, bind to localhost (
127.0.0.1) 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 IPv6 address
Previously, starting from MongoDB 2.6, only the binaries from the official MongoDB RPM (Red Hat, CentOS, Fedora Linux, and derivatives) and DEB (Debian, Ubuntu, and derivatives) packages bind to localhost by default.
When bound only to the localhost, these MongoDB 3.6 binaries can only accept connections from clients (including the
mongo shell, other members in your deployment for replica sets and sharded clusters) that are running on the same machine. Remote clients cannot connect to the binaries bound only to localhost.
To override and bind to other ip addresses, you can use the
net.bindIp configuration file setting or the
--bind_ip command-line option to specify a list of ip addresses.
Before binding to a non-localhost (e.g. publicly accessible) IP address, ensure you have secured your cluster from unauthorized access. For a complete list of security recommendations, see Security Checklist. At minimum, consider enabling authentication and hardening network infrastructure.
For example, the following
mongod instance binds to both the localhost and the sample ip address
In order to connect to this instance, remote clients must specify the ip address
198.51.100.1 or the hostname associated with the ip address: