Urgent: MailScanner apparently stopped processing...

[Mariano Absatz]

El 9 May 2003 a las 21:54, Julian Field escribió:

> I agree it would stay in the queue and, due to the sorting, would always 
> appear as the first message in the batch. But why would it jam anything?
> It would get found and logged at the start of each batch, but any other 
> messages that later appeared would still be added to the batch.
> So it would cause a log warning at the start of each batch, but what harm 
> would it do otherwise?
This was my first thought and that's why I didn't tell you the first time... 
but Leo thinks something is going wrong there... I'll ask him on Monday to do 
a bunch of tests (actually, the only time he saw it happen was by actually 
feeding by hand a manually constructed queue file that contained a typo).

> I could add it to a hash of known bad messages if you like, so that it 
> ignored that message id in subsequent queue scans. But I don't see how the 
> current system actually breaks.
I'd rather quarantine the message at the end of ReadQf() (before the 
return 0)...

> 
> At 20:05 09/05/2003, you wrote:
> >Julian,
> >
> >Leo Helman (the guy who actually wrote most of ZMailer support) spotted this
> >one a few days ago and I thought it was just unelegant, but it might indeed
> >be a bug... if it is so, it affects _all_ versions (sendmail, exim, zmailer &
> >postfix)... maybe it showed up because of some problem in the postfix queue
> >file parser, but it is there anyway.
> >
> >Leo says that within MailScanner::Sendmail::CreateBatch() you have the
> >following code excerpt:
> >
> >       $batchempty = 1;
> >
> >       while(($file = shift @SortedFiles) &&
> >             $HitLimit1+$HitLimit2+$HitLimit3+$HitLimit4<1) {
> >         .... .... ....
> >         .... .... ....
> >         $newmessage = MailScanner::Message->new($id, $queuedirname);
> >         next unless $newmessage;
> >         .... .... ....
> >         .... .... ....
> >       }
> >
> >       # Wait a bit until I check the queue again
> >       sleep(MailScanner::Config::Value('queuescaninterval')) if $batchempty;
> >     } while $batchempty; # Keep trying until we get something
> >
> >now, newmessage is false when a lock fails or when there was an error parsing
> >the envelope (e.g. missing envelope from, to or origin).
> >
> >If the lock failed, that is because another MailScanner locked it and the
> >next round of the loop or so, the file will probably be not there, 'cause the
> >other MailScanner that had it locked, processed it and removed it from the
> >queue.
> >
> >But, if the envelope was corrupt, the file stays in the queue forever, and as
> >$batchempty is not modified, it never quits the loop (the $HitLimitX stay
> >always 0).
> >
> >At first I thought that the only problem would be that the queue file would
> >stay there forever (or until an operator read the log message produced within
> >MailScanner::Sendmail::ReadQf() (smtp MailScanner[xxxx]: Batch: Found invalid
> >queue file for message xxxxxx) and would manually remove it from the queue...
> >
> >In fact, I dismissed a message I was writing to you about this when I thought
> >that... now that Leo read this thread and recalls our dialog back then, I re-
> >read it and notice that, as we always sort the queue files by age, this
> >corrupt file will _always_ be the first to be processed and, hence, would
> >stuck the queue...
> >
> >I think we should differntiate the way ReadQf() fails if the queue file is
> >locked or if it is ill-formed... or change the while() condition...
> >
> >
> >
> >El 9 May 2003 a las 8:46, Julian Field escribió:
> >
> > > At 19:25 08/05/2003, you wrote:
> > > >I'm hoping someone can shed some light on this one - recently I had
> > > >MailScanner which I've implemented on RedHat 8 w/Postfix just yesterday,
> > > >abruptly stop processing mail.
> > > >
> > > >I only happened to notice as the only indication was that no mail was
> > > >passing through to my internal mail/pop servers, etc.
> > > >
> > > >When I checked the maillog I found only entries from the postfix demon
> > > >that receives incoming mail, nothing from MailScanner or the postfix demon
> > > >that then delivers what MailScanner gives it. All processes including the
> > > >MailScanner processes were running - in fact, MailScanner was using a
> > > >majority of cpu time. I tried manually starting up MailScanner and found
> > > >that this fact of "MailScanner starting" and "xxx messages found to be
> > > >scanned" did show up in the maillog, however, no other change, mail did
> > > >not start to flow.
> > > >
> > > >I finally restarted the server and then everything started to move.
> > >
> > > But was it scanning after you restarted?
> > >
> > > Have you use redhat-switchmail-nox to set which email system RedHat thinks
> > > it is trying to run?
> > >
> > > >So, based on this I have a few questions:
> > > >
> > > >1. Any ideas why this happened and how can I prevent it and also does
> > > >anyone have any scripts out there that detect this kindof thing and then
> > > >cleanly shut down mailscanner and restart it?
> > > >
> > > >2. I realized I don't even know how to cleanly shut down MailScanner
> > > >manually. This may seem a stupid question but if someone could answer it
> > > >that would be great.
> > >
> > > service MailScanner stop
> > >
> > > You can do "service MailScanner" to get a list of the command options you
> > > can give it.
> > > Does "service MailScanner start" work cleanly, or does it output any 
> > errors?
> > >
> > > >4. I have an error message repeatedly showing up in the maillog that I
> > > >have been unable to discover the cause of. It is:
> > > >smtp MailScanner[xxxx]: Batch: Found invalid queue file for message xxxxxx
> > >
> > > For some reason it thinks one of your incoming queue files is corrupt. It
> > > needs to be able to find the sender and recipient addresses, and the last
> > > hop IP address, in the file it lifts from the queue.
> > >
> > > Can you send me one of the files from /var/spool/postfix.in/deferred that
> > > exhibits this problem.
> > > Then I can improve the Postfix parser to stop it happening again.
> > > --
> > > Julian Field
> > > www.MailScanner.info
> > > MailScanner thanks transtec Computers for their support
> >
> >
> >--
> >Mariano Absatz
> >El Baby
> >----------------------------------------------------------
> >I am not afraid of death, I just don't want to
> >be there when it happens.
> >         -- Woody Allen
> 
> -- 
> Julian Field
> www.MailScanner.info
> Professional Support Services at www.MailScanner.biz
> MailScanner thanks transtec Computers for their support


--
Mariano Absatz
El Baby
----------------------------------------------------------
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