followup: stuck lmtpd processes

[John C. Amodeo]

...until your system runs out of available open files...

Then the real fun begins... :-)

-John

Andrew Morgan wrote:

> On Wed, 24 Sep 2003, John Wade wrote:
>
> > The patch I wrote still might help you since it would prevent an
> > individual user's problem from taking down the mail system.   The user's
> > mailbox would remain inaccessible, but the lmtpd processes attempting
> > delivery would exit with errors and mail delivery as a whole would
> > proceed.     I still belive that a system with that uses locking with no
> > timeout mechanism is inherently fragile.  A single programming error can
> > lead to a cascade failure that takes down the entire mail system as more
> > and more processes hang up trying to get the lock.
>
> In this case, the problem only affected a single user.  Anything that
> tried to get a lock on that user's quota file hung.  I had a lot of lmtpd
> processes hung waiting for the lock, but that didn't really impact the
> system.  The other users of the system were unaffected.
>
> I'm not saying it is acceptable, but the impact was minor.
>
>         Andy

--
_____________________________________________________________
John C. Amodeo - Associate Director of Information Technology
Faculty of Arts and Sciences -- Computer & Network Operations
Rutgers, The State University of New Jersey
732.932.9455-voice 732.932.0013-fax