DOCS-401 major edits: dupe key in local.slaves

Author: Bob Grabar

source/administration/replica-sets.txt

@@ -932,40 +932,29 @@ scan and pull the entire oplog into memory.
 Duplicate Key Error on local.slaves
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-The duplicate key error on local.slaves, shown below, occurs when a
-connected host changes its hostname. This is a benign error and does not
-affect operations.
+The *duplicate key on local.slaves* error, shown below, occurs when a
+:term:`secondary` or :term:`slave` changes its hostname and the
+:term:`primary` or :term:`master` tries to update its ``local.slaves``
+collection with the new name but runs into a duplicate `_id` field. The
+duplicate `_id` field exists in a document containing the previous
+hostname.
 
 .. example::
 
    .. code-block:: javascript
 
       exception 11000 E11000 duplicate key error index: local.slaves.$_id_  dup key: { : ObjectId('<object ID>') } 0ms 
 
-The error occurs when a host connected to the current host, either
-through :term:`replica sets <replica set>` or through :term:`master`- :term:`slave`
-configuration, changes its hostname. The ``local.slaves`` collection
-creates a new document with the new hostname but also keeps the old
-document with the old hostname. The local.slaves`` collection now has
-two documents with the same ``_id`` field.
+This is a benign error and does not affect replication operations on
+the :term:`secondary` or :term:`slave`.
 
-.. example:: This example shows a ``local.slaves`` collection where the
-   hostname for ``mdb1.example.net`` changed to ``db1.example.net``. Both
-   hostnames still exist in the collection, and both have the same ``_id``.
-
-   .. code-block:: javascript
-
-      PRIMARY> db.slaves.find()
-      { "_id" : "101", "host" : "mdb1.example.net", "ns" : "local.oplog.rs", "syncedTo" : Timestamp(1338775234001, 1) }
-      { "_id" : "102", "host" : "mdb2.example.net", "ns" : "local.oplog.rs", "syncedTo" : Timestamp(1338775234002, 1) }
-      { "_id" : "101", "host" : "db1.example.net", "ns" : "local.oplog.rs", "syncedTo" : Timestamp(1349290750000, 1) }
-
-To stop the error from appearing, drop the ``local.slaves`` collection, as
-shown here:
+To stop the error from appearing, drop the ``local.slaves`` collection
+from the :term:`primary` or :term:`master`, as shown here:
 
 .. code-block:: javascript
 
    db.slaves.drop()
 
-At the next synchronization of the replica set or the master-slave configuration, MongoDB re-creates the
-``local.slaves`` collection and records only the current hostnames.
+The next time a :term:`secondary` or :term:`slave` polls the
+:term:`primary` or :term:`master`, the :term:`primary` or :term:`master`
+recreates the ``local.slaves`` collection.