[slurm-users] draining nodes due to failed killing of task?

[Adrian Sevcenco]

Having just implemented some triggers i just noticed this:

NODELIST    NODES PARTITION       STATE CPUS    S:C:T MEMORY TMP_DISK WEIGHT AVAIL_FE REASON
alien-0-47      1    alien*    draining   48   48:1:1 193324   214030      1 rack-0,4 Kill task failed
alien-0-56      1    alien*     drained   48   48:1:1 193324   214030      1 rack-0,4 Kill task failed

i was wondering why a node is drained when killing of task fails and how can i disable it? (i use cgroups)
moreover, how can the killing of task fails? (this is on slurm 19.05)

Thank you!
Adrian