Starting of <FUNC_NAME> took too long.

This warning appears in the HABApp log, e.g.:

Starting of MyRule.my_func took too long: 0.08s. Maybe there are not enough threads?

It means that the duration from when the event was received to the start of the execution of the function took longer than expected.

This can be the case if suddenly many events are received at once. Another reason for this warning might be that currently running function calls take too long to finish and thus no free workers are available. This can either be the case for complex calculations, but most of the time it’s blocking function calls or a time.sleep call.

If these warnings pile up in the log it’s an indicator that the worker is congested. Make sure there is no use of long sleeps and instead the scheduler is used.

If this warning only appears now and then it can be ignored.


ValueError: Line is too long

The underlaying libraries of HABApp use a buffer to process each request and event from openHAB. If the openHAB items contain images this buffer might be not enough and a ValueError: Line is too long error will appear in the logs. See the openHAB connection options on how to increase the buffer. The maximum image size that can be used without error is ~40% of the buffer size.