(DOCS-15435): Backport oplogBatchDelayMillis parameter (#1338)

Author: jeff-allen-mongo

source/reference/parameters.txt

@@ -2128,6 +2128,39 @@ If you attempt to update ``disableSplitHorizonIPCheck`` at runtime,
 
       mongod --setParameter maxSessions=1000
 
+.. parameter:: oplogBatchDelayMillis
+
+   .. versionadded:: 5.0.10
+
+   |both|
+
+   *Type*: integer
+
+   *Default*: 0
+
+   The number of milliseconds to delay applying batches of oplog
+   operations on secondary nodes. By default, ``oplogBatchDelayMillis``
+   is ``0``, meaning oplog batches are applied with no delay. When there
+   is no delay, MongoDB may apply frequent, small oplog batches to
+   secondaries.
+
+   Increasing ``oplogBatchDelayMillis`` causes MongoDB to apply oplog
+   batches less frequently on secondaries, with each batch containing
+   larger amounts of data. This reduces :abbr:`IOPS (Input/Output
+   Operations Per Second)` on secondaries, but adds latency for writes
+   with write concern :writeconcern:`"majority"`.
+
+   You can only set ``oplogBatchDelayMillis`` at startup. You cannot set
+   ``oplogBatchDelayMillis`` during runtime.
+
+   For example, run the following command to set the
+   ``oplogBatchDelayMillis`` for a :binary:`~bin.mongod` instance to 20
+   milliseconds:
+
+   .. code-block:: bash
+
+      mongod --setParameter oplogBatchDelayMillis=20
+
 .. parameter:: TransactionRecordMinimumLifetimeMinutes
 
    .. versionadded:: 3.6
@@ -2827,7 +2860,7 @@ Sharding Parameters
    and :method:`delete <db.collection.deleteOne>` operations.
 
    For example, to set the maximum percentage to 20, you can issue the
-   followingduring startup:
+   following during startup:
 
    .. code-block:: bash