diff --git a/source/tutorial/add-replica-set-arbiter.txt b/source/tutorial/add-replica-set-arbiter.txt index 1713cc527a2..11351781a08 100644 --- a/source/tutorial/add-replica-set-arbiter.txt +++ b/source/tutorial/add-replica-set-arbiter.txt @@ -4,53 +4,53 @@ Add an Arbiter to Replica Set .. default-domain:: mongodb -Arbiters are special :program:`mongod` instances that do not hold a -copy of the data and thus cannot become primary. Arbiters exist solely -to participate in :ref:`elections `. Because -arbiters do not hold a copies of collection data, they have minimal -resource requirements and do not require dedicated hardware; you may -safely deploy an arbiter on a system with another workload, such as an -application server or monitoring member. +Arbiters are :program:`mongod` instances that exist solely to +participate in :ref:`elections `. Add an arbiter +when a :term:`replica set` has an even number of voting members. The +arbiter gives the set an odd number and prevents election ties. + +An arbiter cannot become primary and does not hold a copy of the data +set. Arbiters have minimal resource requirements and do not require +dedicated hardware. You can deploy an arbiter on a system with another +workload, such as an application server or monitoring member. However, +you cannot run an arbiter on an system with an active :term:`primary` or +:term:`secondary` of the same replica set. .. warning:: - Do not run arbiter processes on a system that is an active - :term:`primary` or :term:`secondary` of its :term:`replica set`. + Do not run an arbiter on an active primary or secondary of the same + replica set. Add an Arbiter -------------- -.. note:: - To prevent tied :term:`elections `, do not add an arbiter - to a set if the set already has an odd number of voting members. - 1. Create a data directory for the arbiter. The :program:`mongod` uses - this directory for configuration information. It *will not* hold - database collection data. The following example creates the - ``/data/arb`` data directory: + the directory for configuration information. The directory *will not* + hold the data set. The following example creates the ``/data/arb`` + data directory: .. code-block:: sh mkdir /data/arb -#. Start the arbiter, making sure to specify the replica set name and - the data directory. Consider the following example: +#. Start the arbiter. Specify the data directory and the replica set + name. The following example specifies the ``/data/arb`` data + directory and the ``rs`` replica set: .. code-block:: sh mongod --port 30000 --dbpath /data/arb --replSet rs -#. In a :program:`mongo` shell connected to the :term:`primary`, add the - arbiter to the replica set by issuing the :method:`rs.addArb()` - method, which uses the following syntax: +#. Connect to the primary and add the arbiter to the replica set. Use + the :method:`rs.addArb()` method, which uses the following syntax: .. code-block:: javascript rs.addArb("<:port>") - For example, if the arbiter runs on ``m1.example.net:30000``, you - would issue this command: + .. example:: The following command add an arbiter that runs on + ``m1.example.net:30000``: - .. code-block:: javascript + .. code-block:: javascript - rs.addArb("m1.example.net:30000") + rs.addArb("m1.example.net:30000")