openHAB 5.1 Release discussion

Searching Googe for this error and watching the “AI” reply has unfortunately made OH “famous enough” to be considered the primary cause for this error:

The log message

[jetty.util.thread.QueuedThreadPool] - Stopped without executing or closing null is a warning from the Jetty server indicating that an attempt was made to add a null job to the thread pool, which is generally a symptom of a problem in the application code that uses Jetty, or potentially a bug in a specific version or binding (like in an openHAB context).

Cause of the Error

This message typically occurs when:

  • A null task is passed to the execute() method of the QueuedThreadPool. The thread pool is designed to handle valid tasks and will log this warning if it receives a null value, as it cannot process a non-existent job.
  • Underlying connection issues: In application platforms like openHAB, this warning has been frequently linked to problems with specific bindings (notably the Shelly binding) where connections (like WebSockets) are not being closed properly, leading to resource leaks, parked threads, and eventually out-of-memory issues or application instability.
  • Abrupt connection closure: The message can be a secondary symptom of a client or server abruptly closing a connection, leaving a pending task in an invalid state.

I guess that’s not the kind of fame we’re looking for?

That said, is the Shelly binding involved here, like Google suggests?