DOCS-246 changes to all of change-oplog-size

Author: Bob Grabar

source/administration/replica-sets.txt

@@ -57,8 +57,8 @@ configurations.
 .. _replica-set-secondary-only-members:
 .. _replica-set-secondary-only-configuration:
 
-Secondary-Only
-~~~~~~~~~~~~~~
+Secondary-Only Members
+~~~~~~~~~~~~~~~~~~~~~~
 
 The secondary-only configuration prevents a :term:`secondary` member in a
 :term:`replica set` from ever becoming a :term:`primary` in a
@@ -119,8 +119,8 @@ This sets the following:
 .. _replica-set-hidden-members:
 .. _replica-set-hidden-configuration:
 
-Hidden
-~~~~~~
+Hidden Members
+~~~~~~~~~~~~~~
 
 Hidden members are part of a replica set but cannot become
 primary and are invisible to client applications. *However,*
@@ -164,8 +164,8 @@ other members in the set will not advertise the hidden member in the
 .. _replica-set-delayed-members:
 .. _replica-set-delayed-configuration:
 
-Delayed
-~~~~~~~
+Delayed Members
+~~~~~~~~~~~~~~~
 
 Delayed members copy and apply operations from the primary's :term:`oplog` with
 a specified delay. If a member has a delay of one hour, then
@@ -220,12 +220,9 @@ queries in normal operations.
    <members[n].slaveDelay>` window, the delayed member cannot
    successfully replicate operations.
 
-.. see:: For more information about delayed members, see the
-   section on :ref:`Delayed Replication <replica-set-delayed-members>`.
-   Additionally consider the following resources:
-  :data:`members[n].slaveDelay`, :ref:`Replica Set Reconfiguration
-  <replica-set-reconfiguration-usage>`, :ref:`Oplog Sizing
-  <replica-set-oplog-sizing>`, and :doc:`/tutorial/change-oplog-size`.
+.. seealso:: :data:`members[n].slaveDelay`, :ref:`Replica Set Reconfiguration
+   <replica-set-reconfiguration-usage>`, :ref:`replica-set-oplog-sizing`,
+   and :doc:`/tutorial/change-oplog-size`.
 
 .. index:: replica set members; arbiters
 .. _replica-set-arbiters:
@@ -289,8 +286,8 @@ hostname and the port.
 .. _replica-set-non-voting-members:
 .. _replica-set-non-voting-configuration:
 
-Non-Voting
-~~~~~~~~~~
+Non-Voting Members
+~~~~~~~~~~~~~~~~~~
 
 You may choose to change the number of votes that each member has in
 :ref:`elections <replica-set-elections>` for :term:`primary`. In general, all
@@ -487,36 +484,6 @@ of the member with the highest :data:`members[n].priority` setting.
    <replica-set-reconfiguration-usage>` example revolves around
    changing the priorities of the :data:`members` of a replica set.
 
-.. _replica-set-procedure-change-oplog-size:
-
-Changing Oplog Size
-~~~~~~~~~~~~~~~~~~~
-
-The :term:`oplog` exists internally as a :term:`capped collection`, so
-you cannot modify its size in the course of normal operations. In most
-cases the :ref:`default oplog size <replica-set-oplog-sizing>` is an
-acceptable size; however, in some situations you may need a larger or
-smaller oplog. To resize the oplog, follow these steps:
-
-#. Restart the current :term:`primary` instance in the :term:`replica set` in
-   "standalone" mode, running on a different port.
-
-#. Save the last entry from the old (current) oplog and create a
-   backup of the oplog.
-
-#. Drop the existing oplog and create a new oplog of a different size.
-
-#. Insert the previously saved last entry from the old oplog into the
-   new oplog.
-
-#. Restart the server as a member of the replica set on its usual
-   port.
-
-#. Apply this procedure to any other member of the replica set that
-   *could become* primary.
-
-.. seealso:: The :doc:`/tutorial/change-oplog-size` tutorial.
-
 .. _replica-set-security:
 
 Security
@@ -657,10 +624,10 @@ Possible causes of replication lag include:
 
   For more information see:
 
-  - the :ref:`Replication Write Concern <replica-set-write-concern>` section,
-  - the :ref:`replica-set-oplog` documentation,
-  - the :ref:`Oplog Sizing <replica-set-oplog-sizing>` section, and
-  - the :doc:`/tutorial/change-oplog-size` tutorial.
+  - :ref:`replica-set-write-concern`.
+  - The :ref:`replica-set-oplog-sizing` topic in the :doc:`/core/replication` document.
+  - The :ref:`replica-set-oplog` topic in the :doc:`/core/replication-internals` document.
+  - The :doc:`/tutorial/change-oplog-size` tutorial.
 
 .. index:: pair: replica set; failover
 .. _replica-set-failover-administration:

source/core/replication-internals.txt

@@ -18,7 +18,7 @@ troubleshooting and for further understanding MongoDB's behavior and approach.
 Oplog
 -----
 
-For an explanation of the oplog, see the :ref:`oplog <replica-set-oplog-sizing>`
+For an explanation of the oplog, see the :ref:`replica-set-oplog-sizing`
 topic in the :doc:`/core/replication` document.
 
 Under various exceptional

source/core/replication.txt

@@ -279,7 +279,7 @@ on the :term:`primary` and then records the operations on the primary's
 oplog. The :term:`secondary` members then replicate this log and apply
 the operations to themselves in an asynchronous process. All replica set
 members contain a copy of the oplog, allowing them to maintain the
-current state of the database.
+current state of the database. The oplog is an :term:`idempotent` log.
 
 By default, the size of the oplog is as follows:
 
@@ -297,16 +297,14 @@ By default, the size of the oplog is as follows:
 
 Before oplog creation, you can specify the size of your oplog with the
 :setting:`oplogSize` option. Once the oplog is created, you can only
-change the size of the oplog by using the :ref:`oplog resizing procedure
-<replica-set-procedure-change-oplog-size>`.
-
-.. QUESTION: SK, Can the next graph be rewritten? It's unclear to me. BG
-
-For example, if an oplog fits 24 hours of operations, then members can
-stop copying entries from the oplog for 24 hours before they require
-full resyncing *and* the disk will be full in 19 days. If this were
-the case, you would have a very high-volume member. In many
-circumstances, the default oplog can hold days of operations.
+change the size of the oplog by using the :doc:`/tutorial/change-oplog-size` tutorial.
+
+In most cases, the default oplog size is sufficient. For example, if an
+oplog that is 5% of free disk space fills up in an hour, then
+secondaries can stop copying entries from the oplog for 20 hours before
+they require full resyncing. If this were the case, you would have a
+very high-volume member. In many circumstances, the default oplog can
+hold days of operations.
 
 The following factors affect how MongoDB uses space in the oplog: