In some MX-series BNG router, occasionally, the /var/tmp directory could be filling up with "sts_lock_holder.lock" files.

user@router> file list detail /var/tmp | grep sts

-rw-rw-rw- 1 root wheel 488419328 Sep 30 14:13 sts_lock_holder.pid10404.lock

-rw-rw-rw- 1 root wheel 325603328 Sep 30 14:13 sts_lock_holder.pid10409.lock

-rw-rw-rw- 1 root wheel 494886912 Jan 12 01:43 sts_lock_holder.pid10593.lock

-rw-rw-rw- 1 root wheel 327880704 Jan 12 01:43 sts_lock_holder.pid10601.lock

-rw-rw-rw- 1 root wheel 494886912 Jan 29 05:10 sts_lock_holder.pid12435.lock

In rare instances when concurrently multiple processes try to take multiple SDB STS locks, a locking deadlock can occur. The deadlock is detected and broken and after required daemons restart system functions normally.

Chance of deadlock occurring is rare. And this must happen in a small timing window.

Since the file size is quite big, the customer can feel free to delete these files.