[ mailman-Bugs-1168999 ] OutgoingRunner gets in expensive recursive loop

[SourceForge.net]

Bugs item #1168999, was opened at 2005-03-23 18:30
Message generated for change (Tracker Item Submitted) made by Item Submitter
You can respond by visiting: 
https://sourceforge.net/tracker/?func=detail&atid=100103&aid=1168999&group_id=103

Category: mail delivery
Group: 2.1 beta
Status: Open
Resolution: None
Priority: 5
Submitted By: Kim Davies (kjd)
Assigned to: Nobody/Anonymous (nobody)
Summary: OutgoingRunner gets in expensive recursive loop

Initial Comment:
I have had a problem spring up the past few weeks where
the OutgoingRunner gets in a loop which effectively
brings down the machine by spiking the CPU to 99%.
Running "strace" on the process I see it constantly
deleting and reimplanting the same queue file in
qfiles/out/ over and over, many times per second.

The initial problem inurred with a 2.1.2 install, but
installing 2.1.6b4 shows the same.

Unfortunately the problem is somewhat ephemeral when
trying to diagnose it - if I manage to kill the
OutgoingRunner between a read and write, the queue file
gets lost the the problem disappears for a while. 

I don't know if it is useful, but attached is the
strace output of a
complete read/write cycle. I haven't had the
opportunity to further debug it (by stepping through
the python) as currently I am not in this state. I am
not sure how long it will be until it is triggered
again, but it has happened about 4 times in the past
two weeks. It has never occured before this over 3 years.

I consider this issue fairly problematic - the machine
becomes unusable when it reaches this state due to CPU
exhaustion.

Any tips of helping isolate the problem are welcome. I
have modified mailmanctl to run all queuerunners with a
verbose flag, so next time maybe there will be useful
information logged.

----------------------------------------------------------------------

You can respond by visiting: 
https://sourceforge.net/tracker/?func=detail&atid=100103&aid=1168999&group_id=103