convert-replica-set-to-replicated-shard-cluster.txt

==========================================
Convert a Replica Set to a Sharded Cluster
==========================================

.. default-domain:: mongodb

.. contents:: On this page
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   :backlinks: none
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Overview
--------

This tutorial converts a single three-member replica set to a sharded
cluster with two shards. Each shard is an independent three-member
replica set. This tutorial is specific to MongoDB |version|. For other
versions of MongoDB, refer to the corresponding version of the MongoDB
Manual.

The procedure is as follows:

#. Create the initial three-member replica set and insert data into a
   collection. See :ref:`convert-setup-initial-set`.

#. Start the config servers and a :program:`mongos`. See
   :ref:`convert-deploy-sharding-infrastructure`.

#. Add the initial replica set as a shard. See
   :ref:`convert-add-initial-shard`.

#. Create a second shard and add to the cluster. See
   :ref:`convert-add-second-shard`.

#. Shard the desired collection. See :ref:`convert-shard-collection`.

Prerequisites
-------------

This tutorial uses a total of ten servers: one server for the
:program:`mongos` and three servers each for the first :term:`replica
set`, the second replica set, and the :doc:`config server replica set
</core/sharded-cluster-config-servers>`. 

Each server must have a resolvable domain, hostname, or IP address
within your system.

The tutorial uses the default data directories (e.g. ``/data/db`` and
``/data/configdb``). Create the appropriate directories with
appropriate permissions. To use different paths, see
:doc:`/reference/configuration-options` .

Procedures
----------

.. _convert-setup-initial-set:

Set Up Initial Replica Set
~~~~~~~~~~~~~~~~~~~~~~~~~~

This procedure creates the initial three-member replica set ``rs0``.
The replica set members are on the following hosts:
``mongodb0.example.net``, ``mongodb1.example.net``, and
``mongodb2.example.net``.

.. include:: /includes/steps/convert-replica-set-shard-deploy-test-data.rst

For more information on deploying a replica set, see
:doc:`/tutorial/deploy-replica-set`.

Restart the Replica Set as a Shard
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

.. versionchanged:: 3.4

  .. include:: /includes/fact-3.4-shardsvr-required.rst

.. include:: /includes/steps/convert-replica-set-shard-aware.rst

.. _convert-deploy-sharding-infrastructure:

Deploy Config Server Replica Set and ``mongos``
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

This procedure deploys the three-member replica set for the :doc:`config
servers </core/sharded-cluster-config-servers>` and the
:program:`mongos`.

- The config servers use the following hosts: ``mongodb7.example.net``,
  ``mongodb8.example.net``, and ``mongodb9.example.net``.

- The :program:`mongos` uses ``mongodb6.example.net``.

.. include:: /includes/steps/convert-replica-set-shard-deploy-infrastructure.rst

.. _convert-add-initial-shard:

Add Initial Replica Set as a Shard
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The following procedure adds the initial replica set ``rs0`` as a shard.

.. include:: /includes/steps/convert-replica-set-add-shards.rst

.. _convert-add-second-shard:

Add Second Shard
~~~~~~~~~~~~~~~~

The following procedure deploys a new replica set ``rs1`` for the
second shard and adds it to the cluster. The replica set members are on
the following hosts: ``mongodb3.example.net``,
``mongodb4.example.net``, and ``mongodb5.example.net``.

.. versionchanged:: 3.4

  .. include:: /includes/fact-3.4-shardsvr-required.rst

.. include:: /includes/steps/convert-replica-set-add-new-shard.rst

.. _convert-shard-collection:

Shard a Collection
~~~~~~~~~~~~~~~~~~

.. include:: /includes/steps/convert-replica-set-enable-sharding.rst