replSetInitiate.txt

===============
replSetInitiate
===============

.. default-domain:: mongodb

.. contents:: On this page
   :local:
   :backlinks: none
   :depth: 1
   :class: singlecol

.. dbcommand:: replSetInitiate

   The :dbcommand:`replSetInitiate` command initializes a new replica set.
   
   .. |command| replace:: ``replSetInitiate``

   .. include:: /includes/fact-dbcommand.rst

   .. note::

      Run the command on only one of the :binary:`~bin.mongod` instances
      for the replica set.

   Use the following syntax:

   .. code-block:: javascript

      { replSetInitiate : <config_document> }

   The ``<config_document>`` is a :term:`document` that specifies
   the replica set's configuration. For instance, here's a config document
   for creating a simple 3-member replica set:

   .. code-block:: javascript

      {
          _id : <setname>,
           members : [
               {_id : 0, host : <host0>},
               {_id : 1, host : <host1>},
               {_id : 2, host : <host2>},
           ]
      }


IP Binding
----------

.. include:: /includes/fact-default-bind-ip.rst


Example
-------

Assign a config document to a variable and then to pass the document to
the :method:`rs.initiate()` helper:

.. code-block:: javascript

   config = {
       _id : "my_replica_set",
        members : [
            {_id : 0, host : "rs1.example.net:27017"},
            {_id : 1, host : "rs2.example.net:27017"},
            {_id : 2, host : "rs3.example.net", arbiterOnly: true},
        ]
   }

   rs.initiate(config)

Notice that omitting the port cause the host to use the default port
of 27017. Notice also that you can specify other options in the config
documents such as the ``arbiterOnly`` setting in this example.

.. slave-ok, admin-only

.. seealso:: :doc:`/reference/replica-configuration`,
   :doc:`/administration/replica-set-deployment`, and :ref:`Replica Set
   Reconfiguration <replica-set-reconfiguration-usage>`.