On Fri, 26 Jun 2009, Sebastian Hagedorn wrote:
On 6/18/09 7:11 PM, Bryan Harrison at br...@bryanharrison.com wrote:
If I allow launchd to start it
S<caron>I get an endless succession ofS<caron>
Jun 18 16:50:26 org.list.mailmanctl[1697]: Starting Mailman's master
qrunner.
Jun 18 16:50:26 com.apple.launchd[1] (org.list.mailmanctl[1697]):
Stray process with PGID equal to this dead job: PID 1698 PPID 1 Python
Jun 18 16:50:26 com.apple.launchd[1] (org.list.mailmanctl): Throttling
respawn: Will start in 9 seconds
I just caught that Bryan notes that he receives an "endless succession" of
those messages where as I see one and that's it.
Comparing our launchd .plist files, I see a few differences:
Bryan:
<key>OnDemand</key>
<false/>
Me:
<key>OnDemand</key>
<true/>
<key>RunAtLoad</key>
<true/>
Bryan does not have RunAtLoad but the default is false. I think this is
why he sees the "endless succession" and I don't. Wiht RunAtLoad but
OnDemand set true, my system tries once at startup and that's it. Bryan,
due to OnDemand being false (meaning keep it running continuously), keeps
trying.
Another difference (but I think making no difference is:
Bryan:
<key>Program</key>
<string>/usr/share/mailman/bin/mailmanctl</string>
<key>ProgramArguments</key>
<array>
<string>mailmanctl</string>
<string>-s</string>
<string>start</string>
</array>
Me:
<key>ProgramArguments</key>
<array>
<string>/Applications/Mailman/bin/mailmanctl</string>
<string>-s</string>
<string>start</string>
</array>
I don't have a Program key. I don't think this is relevant as I specify
the full path in ProgramArguments which Bryan does not need to do since he
specified the path in Program.
The reason this happens is that launchd expects the processes it
launches to stick around. They must not daemonize. But mailmanctl
terminates after it has started the runners. I assume that Apple
modified their own distribution of Mailman so that mailmanctl behaves
differently. I'd suggest comparing the two.
I'm not so sure. It worked fine for me under Tiger (client). Drew reports
the same thing with OS X Server - worked fine under Tiger (10.4.x) and
then the same problems as the rest of us with Leopard.
Also, I can't say I agree that launchd expects the program to stick
around. With it the way I have it set (RunAtLoad true and OnDemand true),
it makes one attempt at startup and does not care after that whether it
started or not. I'll note that I also have Clam-AV's daemon (clamd)
starting the same way and it seems to work OK but some of the technical
issues of launching daemon with launchd are beyond me. However, the
launchd.plist(5) man page says:
EXPECTATIONS
Daemons or agents managed by launchd are expected to behave certain ways.
A daemon or agent launched by launchd MUST NOT do the following in the
process directly launched by launchd:
o fork(2) and have the parent process exit(3) or _exit(2).
o Call daemon(3)
A daemon or agent launched by launchd SHOULD NOT do the following as a
part of their startup initialization:
Setup the user ID or group ID.
o Setup the working directory.
o chroot(2)
o setsid(2)
o Close "stray" file descriptors.
o Change stdio(3) to /dev/null.
o Setup resource limits with setrusage(2).
o Setup priority with setpriority(2).
o Ignore the SIGTERM signal.
A daemon or agent launched by launchd SHOULD:
o Launch on demand given criteria specified in the XML property
list. More information can be found in launch(3).
o Catch the SIGTERM signal.
I'll leave it to those better into the technical end of things to
interpret that relative to what mailmanctl does.
-- Larry Stone
lston...@stonejongleux.com
------------------------------------------------------
Mailman-Users mailing list
Mailman-Users@python.org
http://mail.python.org/mailman/listinfo/mailman-users
Mailman FAQ: http://wiki.list.org/x/AgA3
Searchable Archives: http://www.mail-archive.com/mailman-users%40python.org/
Unsubscribe:
http://mail.python.org/mailman/options/mailman-users/archive%40jab.org
Security Policy: http://wiki.list.org/x/QIA9
