DOCS-15974-change-stream-metrics (#3115)

* DOCS-15974-change-stream-metrics

* DOCS-15974-change-stream-metrics

* DOCS-15974-change-stream-metrics

* DOCS-15974-change-stream-metrics

---------

Co-authored-by: jason-price-mongodb <[email protected]>

Author: jason-price-mongodb

source/reference/command/serverStatus.txt

@@ -1525,6 +1525,10 @@ metrics
       aggStageCounters : {
          <aggregation stage> : Long("<num>")
       },
+      changeStreams: {
+         largeEventsFailed: Long("<num>"),
+         largeEventsSplit: Long("<num>")
+      },
       commands: {
          <command>: {
             failed: Long("<num>"),
@@ -1849,6 +1853,30 @@ metrics
 
    .. versionadded:: 5.1
 
+.. serverstatus:: metrics.changeStreams
+
+   A document that reports information about :ref:`change stream
+   <changeStreams>` events larger than 16 MB.
+
+   .. versionadded:: 7.0
+
+.. serverstatus:: metrics.changeStreams.largeEventsFailed
+
+   The number of change stream events that caused a
+   ``BSONObjectTooLarge`` exception because the event was larger than 16
+   MB. To prevent the exception, see
+   :pipeline:`$changeStreamSplitLargeEvent`.
+
+   .. versionadded:: 7.0
+
+.. serverstatus:: metrics.changeStreams.largeEventsSplit
+
+   The number of change stream events larger than 16 MB that were split
+   into smaller fragments. Events are only split if you use the
+   :pipeline:`$changeStreamSplitLargeEvent` pipeline stage.
+
+   .. versionadded:: 7.0
+
 .. serverstatus:: metrics.commands
 
    A document that reports on the use of database commands. The fields

source/release-notes/7.0.txt

@@ -25,14 +25,21 @@ Starting in MongoDB 7.0, the :dbcommand:`currentOp` command and the
 
 - :data:`currentOp.admissionPriority`
 
-``$changeStreamSplitLargeEvent`` Pipeline Stage
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Large Change Stream Events
+~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-Starting in MongoDB 7.0, if you have large :ref:`change stream
-<changeStreams>` events that exceed 16 MB, you can use the new
+Starting in MongoDB 7.0, if you have :ref:`change stream
+<changeStreams>` events larger than 16 MB, you can use the new
 :pipeline:`$changeStreamSplitLargeEvent` stage to split the events into
 smaller fragments.
 
+The following new metrics report information about large change stream
+events:
+
+- :serverstatus:`metrics.changeStreams`
+- :serverstatus:`metrics.changeStreams.largeEventsFailed`
+- :serverstatus:`metrics.changeStreams.largeEventsSplit`
+
 New Parameters
 ~~~~~~~~~~~~~~