DOCS-941 review edits

Author: Bob Grabar

source/administration/replica-sets.txt

@@ -349,18 +349,16 @@ from another secondary member instead of from the :term:`primary`. This
 might be the case, for example, if a secondary selects its replication
 target based on ping time and if the closest member is another secondary.
 
-Chained replication has the benefit of providing load balancing in cases
-where the primary is heavily loaded. But, depending on the network
-topology, replication chaining can also result in increased replication
-lag.
+Chained replication can reduce load on the primary. But depending on the network
+topology, chained replication can also result in increased replication lag.
 
 .. versionadded:: 2.2.2
 
 You can use the
 :data:`chainingAllowed <local.system.replset.settings.chainingAllowed>`
 setting in
 :doc:`/reference/replica-configuration` to disable chained replication
-for situations where replication lag is an issue. For details, see
+for situations where chained replication is causing lag. For details, see
 :ref:`replica-set-config-chained-replication`.
 
 Procedures
@@ -631,7 +629,7 @@ You can use the following sequence of commands to set ``chainingAllowed`` to
 
    .. code-block:: javascript
 
-      cfg = rs.conf()
+      cfg = rs.config()
 
 #. Take note of whether the current configuration settings contain the
    ``settings`` sub-document. If they do, skip this step.
@@ -655,8 +653,19 @@ You can use the following sequence of commands to set ``chainingAllowed`` to
       cfg.settings.chainingAllowed = false
       rs.reconfig(cfg)
 
-To re-enable chained replication, use :dbcommand:`replSetSyncFrom` to
-specify that each secondary replicates from the primary.
+To re-enable chained replication, set ``chainingAllowed`` to ``true``.
+You can use the following sequence of commands:
+
+.. code-block:: javascript
+
+   cfg = rs.config()
+   cfg.settings.chainingAllowed = true
+   rs.reconfig(cfg)
+
+.. note:: If chained replication is disabled, you still can use
+   :dbcommand:`replSetSyncFrom` to specify that a secondary replicates
+   from the primary. But that configuration will last only until the
+   secondary recalculates which member to sync from.
 
 .. _replica-set-procedure-change-oplog-size:
 

source/reference/replica-configuration.txt

@@ -217,8 +217,8 @@ Configuration Variables
 
    **Type**: :term:`MongoDB Document <document>`
 
-   The settings document affects replication chaining and
-   available :term:`write concern` options.
+   The ``settings`` document configures options that apply to the whole
+   replica set.
 
 .. data:: local.system.replset.settings.chainingAllowed
 
@@ -232,7 +232,7 @@ Configuration Variables
    members to replicate from other secondary members. When this value is
    ``false``, secondaries can replicate only from the :term:`primary`.
 
-   When you run :method:`rs.conf()` to view a replica set's
+   When you run :method:`rs.config()` to view a replica set's
    configuration, the ``chainingAllowed`` field appears only when it is
    set to ``false``. If ``chainingAllowed`` is set to its default value
    of ``true``, the field does not appear.
@@ -280,20 +280,20 @@ all optional fields.
        {
          _id : <ordinal>,
          host : hostname<:port>,
-         <arbiterOnly : <boolean> >,
-         <buildIndexes : <boolean> >,
-         <hidden : <boolean> >,
-         <priority: <priority> >,
-         <tags: { <document> } >,
-         <slaveDelay : <number> >,
+         <arbiterOnly : <boolean>,>
+         <buildIndexes : <boolean>,>
+         <hidden : <boolean>,>
+         <priority: <priority>,>
+         <tags: { <document> },>
+         <slaveDelay : <number>,>
          <votes : <number>>
        }
        , ...
      ],
      <settings: {
-       <chainingAllowed : <boolean> >,
-       <getLastEerrorDefaults : <lasterrdefaults> >,
-       <getLastErrorModes : <modes> >
+       <chainingAllowed : <boolean>,>
+       <getLastEerrorDefaults : <lasterrdefaults>,>
+       <getLastErrorModes : <modes>>
      }>
    }