bottlenecking?

[Tim Tyler]

Mailscanner,
  This has been my exact observation as well.  I think I may play it safe
and stop and start the process every 20 minutes because its killing the
dependablility of quick and reliable email for my clients.
mailscanner_check just doesn't handle it.
 Tim

>>
>I certainly wouldn't say that it is a common problem or that it happens
>at all frequently. I only see it happen at infrequent intervals. I don't
>know if the problem is load related or message related, but when it
>happens all processing of messages from mqueue.in stops and mail starts
>backing up. By the time I'd notice the problem (usually 15 minutes to a
>hour later) I might have 10-15K messages in the input queue. At that
>point the name of the game is to get the queue cleared and make the
>phone stop ringing, so investigative work mostly has to be done in retro
>spec. I have looked for core files and not found any. So far, simply
>killing the MS process and restarting it causes message processing to
>resume.
>
>For a while I thought that the problem only occurred on my large volume
>servers and was leaning towards a load related cause. But I have
>observed it (even less frequently) on low volume servers (less that 15k
>messages/day). So far I haven't been able to duplicate that failure when
>I save off the contents of the mqueue.in dir and run that though my test
>jig. That might imply that there's some critical set of conditions that
>has to occur to cause MailScanner to go walk-about. One other thing that
>I've observed is that MailScanner always has a batch of messages in
>process at the time of the failure. The same message ID's exist both in
>the work directory and in the input queue. I guess I don't know exactly
>what MS was doing at the time it ran off into the weeds, only that it
>appeared to have been processing messages.
>
>> >The V4 implementation brings new challenges. Not only do you have the
>> >mater process, but you also have a number of child processes to deal
>> >with. I'd like to see a pid file for each of the children, perhaps with
>> >a name of the form mailscanner1.pid, mailscanner2.pid, etc. And it would
>> >be awfully nice is killing the master process would cause it to reap its
>> >children.
>>
>> I happened to write that for you last night. There are pid files for all of
>> the children, and the master creates and destroys these as the children
>> start and stop. I've written an init.d script for it (for RedHat) that has
>> start, stop, restart, status and reload commands. It does the "reload"
>> operation by doing a "kill -HUP" on all the MailScanner processes.
>>
>Very nice.
>--
>The instructions said to use Windows 98 or better, so I installed
>RedHat.
>


--
Tim Tyler
Network Manager - Beloit College
tyler at beloit.edu