1.4.3 (SunOS/sparc): canceled jobs / thousands of 'defunct' processes

[Matthias Apitz]

>
> while stop/start of cupsd (to get rid of the 'socket' backends which have been sitting around) we encountered the following dramatical situation:
>
> the stop of cupsd with the normal stop script (which just does only a "kill pid" thousands (~10.000) of defunct processes were created:
>
>     root  6515  5026   0        - ?           0:00 <defunct>
>       lp  6514  5026   0        - ?           0:00 <defunct>
>       lp  6513  5026   0        - ?           0:00 <defunct>
>     root  6512  5026   0        - ?           0:00 <defunct>
>       lp  6511  5026   0        - ?           0:00 <defunct>
>       lp  6510  5026   0        - ?           0:00 <defunct>
>     root  6509  5026   0        - ?           0:00 <defunct>
>       lp  6508  5026   0        - ?           0:00 <defunct>
>       lp  6507  5026   0        - ?           0:00 <defunct>
>     root  6506  5026   0        - ?           0:00 <defunct>
>       lp  6505  5026   0        - ?           0:00 <defunct>
>       lp  6504  5026   0        - ?           0:00 <defunct>
>     root  6503  5026   0        - ?           0:00 <defunct>
>

The problem is fully reproduceable:

- switch off a network printer
- create a printjob for it
- the process socket is hanging
- stop cupsd
- error log shows thousands of started printing pipelines like:

# fgrep Started /usr/local/sisis-pap/cups/var/log/cups/error_log.O  | wc -l
     789
# fgrep Started /usr/local/sisis-pap/cups/var/log/cups/error_log.O

I [20/Sep/2011:16:20:11 -0100] [Job 2] Started filter /usr/local/sisis-pap/cups/lib/cups/filter/pstops (PID 3379)
I [20/Sep/2011:16:20:11 -0100] [Job 2] Started backend /usr/local/sisis-pap/cups/lib/cups/backend/socket (PID 3381)
I [20/Sep/2011:16:20:11 -0100] [Job 2] Started filter /usr/local/sisis-pap/cups/lib/cups/filter/bannertops (PID 3383)
I [20/Sep/2011:16:20:11 -0100] [Job 2] Started filter /usr/local/sisis-pap/cups/lib/cups/filter/pstops (PID 3384)
I [20/Sep/2011:16:20:11 -0100] [Job 2] Started backend /usr/local/sisis-pap/cups/lib/cups/backend/socket (PID 3387)
I [20/Sep/2011:16:20:11 -0100] [Job 2] Started filter /usr/local/sisis-pap/cups/lib/cups/filter/bannertops (PID 3388)
I [20/Sep/2011:16:20:11 -0100] [Job 2] Started filter /usr/local/sisis-pap/cups/lib/cups/filter/pstops (PID 3389)
I [20/Sep/2011:16:20:11 -0100] [Job 2] Started backend /usr/local/sisis-pap/cups/lib/cups/backend/socket (PID 3391)
I [20/Sep/2011:16:20:11 -0100] [Job 2] Started filter /usr/local/sisis-pap/cups/lib/cups/filter/bannertops (PID 3397)
I [20/Sep/2011:16:20:11 -0100] [Job 2] Started filter /usr/local/sisis-pap/cups/lib/cups/filter/pstops (PID 3398)
I [20/Sep/2011:16:20:11 -0100] [Job 2] Started backend /usr/local/sisis-pap/cups/lib/cups/backend/socket (PID 3402)
I [20/Sep/2011:16:20:11 -0100] [Job 2] Started filter /usr/local/sisis-pap/cups/lib/cups/filter/bannertops (PID 3405)
I [20/Sep/2011:16:20:11 -0100] [Job 2] Started filter /usr/local/sisis-pap/cups/lib/cups/filter/pstops (PID 3407)
I [20/Sep/2011:16:20:11 -0100] [Job 2] Started backend /usr/local/sisis-pap/cups/lib/cups/backend/socket (PID 3412)
I [20/Sep/2011:16:20:11 -0100] [Job 2] Started filter /usr/local/sisis-pap/cups/lib/cups/filter/bannertops (PID 3415)
I [20/Sep/2011:16:20:11 -0100] [Job 2] Started filter /usr/local/sisis-pap/cups/lib/cups/filter/pstops (PID 3416)
I [20/Sep/2011:16:20:11 -0100] [Job 2] Started backend /usr/local/sisis-pap/cups/lib/cups/backend/socket (PID 3418)
I [20/Sep/2011:16:20:11 -0100] [Job 2] Started filter /usr/local/sisis-pap/cups/lib/cups/filter/bannertops (PID 3419)
I [20/Sep/2011:16:20:11 -0100] [Job 2] Started filter /usr/local/sisis-pap/cups/lib/cups/filter/pstops (PID 3420)
I [20/Sep/2011:16:20:11 -0100] [Job 2] Started backend /usr/local/sisis-pap/cups/lib/cups/backend/socket (PID 3421)
...

    matthias