Server log message with 30s interval!?

> I noticed some time ago that the server log contains a lot of the same
> messages with an interval of 30s!? (see part of the server log below).
....
> [16-06-20 17:28:16.7218] Slim::Web::JSONRPC::requestMethod (443) request
> not dispatchable!

These messages usually are caused by some client software polling for
player information for a player which no longer is connected. Eg. the
web UI, or some mobile app.

--

Michael