We observed several situations already where log files reached a file size of over 120G. This caused the worker's disk usage to reach 100% resulting in the worker machine to go "offline", i.e. not being available to pick up new tasks.
The initially observed excessive log spilling is due to a TaskManager failing fatally which results in the requested number of slots never becoming available and the test job ending up in an infinite failover/restart loop. See further details in the comment section.