Merge pull request #13082 from jacobbunk/doc-send-recv-latencies

Document send and receive latency metrics

docs/performance.rst

@@ -229,7 +229,7 @@ Number of entries in the metadata cache
 .. _stat-open-tcp-connections:
 
 open-tcp-connections
-~~~~~~~~~~~~~~~~~~~~
+^^^^^^^^^^^^^^^^^^^^
 Number of currently open TCP connections
 
 .. _stat-overload-drops:
@@ -286,6 +286,12 @@ rd-queries
 ^^^^^^^^^^
 Number of packets sent by clients requesting recursion (regardless of if we'll be providing them with recursion).
 
+.. _stat-receive-latency:
+
+receive-latency
+^^^^^^^^^^^^^^^
+Average number of microseconds needed to receive a query
+
 .. _stat-recursing-answers:
 
 recursing-answers
@@ -394,6 +400,12 @@ timedout-packets
 ^^^^^^^^^^^^^^^^
 Amount of packets that were dropped because they had to wait too long internally
 
+.. _stat-send-latency:
+
+send-latency
+^^^^^^^^^^^^
+Average number of microseconds needed to send the answer
+
 .. _stat-udp-answers-bytes:
 
 udp-answers-bytes