[3.10] gh-91305: Add a note about DatagramHandler and DNS latency. (G…

…H-96380) (GH-96400)

Doc/library/logging.handlers.rst

@@ -572,6 +572,13 @@ over UDP sockets.
    Returns a new instance of the :class:`DatagramHandler` class intended to
    communicate with a remote machine whose address is given by *host* and *port*.
 
+   .. note:: As UDP is not a streaming protocol, there is no persistent connection
+      between an instance of this handler and *host*. For this reason, when using a
+      network socket, a DNS lookup might have to be made each time an event is
+      logged, which can introduce some latency into the system. If this affects you,
+      you can do a lookup yourself and initialize this handler using the looked-up IP
+      address rather than the hostname.
+
    .. versionchanged:: 3.4
       If ``port`` is specified as ``None``, a Unix domain socket is created
       using the value in ``host`` - otherwise, a UDP socket is created.