DOCPS-16201 counters for legacy op codes

Author: mungitoperrito

source/reference/command/serverStatus.txt

@@ -2042,6 +2042,35 @@ opcounters
 
    .. include:: /includes/extracts/4.2-changes-opcounters-type.rst
 
+.. serverstatus:: opcounters.deprecated
+
+   This section only appears in the :method:`db.serverStatus()` output
+   when one of the following, deprecated opcodes has been used:
+   
+   .. code-block:: javascript
+
+      "deprecated": {
+         "opQuery": NumberLong(<num>),
+         "opGetMore": NumberLong(<num>),
+         "opKillCursors": NumberLong(<num>),
+         "opDelete": NumberLong(<num>),
+         "opUpdate": NumberLong(<num>),
+         "opInsert": NumberLong(<num>),
+         "total": NumberLong(<num>),
+      }
+
+   These opcodes were deprecated in MongoDB 5.0 and support for these
+   opcodes is removed in MongoDB 5.1. Starting in MongoDB 5.1,
+   :binary:`~bin.mongod` refuses requests that use a deprecated
+   opcode and increments the corresponding counter.
+
+   ``OP_QUERY`` is an exception to the general rule.
+   :binary:`~bin.mongod` continues to support ``hello`` and
+   ``isMaster`` requests that use ``OP_QUERY``. :binary:`~bin.mongod`
+   refuses any other ``OP_QUERY`` requests.
+
+   The counters are reset when :binary:`~bin.mongod` starts.
+
 .. _server-status-opcountersrepl:
 .. _server-status-opcounters-repl:
 

source/release-notes/5.0-compatibility.txt

@@ -471,7 +471,7 @@ MongoDB 5.0 deprecates the following
 - ``OP_KILL_CURSORS``
 
 Newer driver versions use :ref:`OP_MSG <wire-op-msg>` instead of these
-deprecated op codes. 
+deprecated opcodes. 
 
 The related commands and methods are also deprecated in MongoDB 5.0:
 

source/release-notes/5.1.txt

@@ -115,6 +115,10 @@ Aggregation Metrics
     indicates how often
     :ref:`match expressions <query-projection-operators-top>` ran.
 
+Opcode Counters
+  - :serverstatus:`opcounters.deprecated` A count of how often
+    deprecated opcodes run.
+
 Resharding Statistics
   - :serverstatus:`shardingStatistics.resharding.lastOpEndingChunkImbalance`