Wrapper Log Filling with Exception in thread

It appears to reference a thread that isn’t listed on the gateway Threads page. How do I get more info on this to find the problem? Here is a paste:
Exception in thread Thread-1697138:Traceback (most recent call last):
INFO | jvm 1 | 2020/04/21 16:29:50 | File “/var/lib/ignition/user-lib/pylib/threading.py”, line 222, in _Thread__bootstrap
INFO | jvm 1 | 2020/04/21 16:29:50 | self.run()
INFO | jvm 1 | 2020/04/21 16:29:50 | File “/var/lib/ignition/user-lib/pylib/threading.py”, line 360, in run
INFO | jvm 1 | 2020/04/21 16:29:50 | self.function(*self.args, **self.kwargs)

If I look, there is no thread “Thread-1697138” that I can find. About 90 of these are hitting the wrapper log every 6 seconds or so.
Ignition 8.0.10(b2020031912) Linux, java version 11.0.6+10LTS

Thanks

This was resolved by Support. Root cause was a gateway timer script that used threading. Support advised I should use time.sleep instead of threading. This worked.

Support recommended this? Somebody needs to be retrained. Expect those sleep calls to eventually cause strange performance side effects in other parts of Ignition.

Seriously, no form of sleep should be used outside of a thread started by system.util.invokeAsynchronous.

You weren't finding those threads because that error is fatal. The thread wouldn't exist after the error was logged.