Re: IMAP/LMTP delays (was Re: IMAPD Mail Delays)

From: Mike Eggleston (no email)
Date: Wed Sep 05 2007 - 19:43:37 EDT

  • Next message: Bron Gondwana: "Re: ...and a question (SHA1 UUIDs)"

    On Wed, 05 Sep 2007, Michael D. Sofka might have said:

    > On Tuesday 04 September 2007 03:42:05 pm Corey Bobb wrote:
    > > The current problem I am having is that I am receiving mail from my outside
    > > email relay (postfix) which From what I gather forwards it over the cyrus
    > > mail sever however, I can see the postfix server getting the mail . ..but
    > > it will take another 30 minutes before the message can actually be viewed
    > > in a mail client.
    >
    > I've been seeing this as well. In our case, it's cyrus 2.2.12 with
    > sendmail 8.13.1 using MAILER(cyrus2). Cyrus is run in a murder cluster with a
    > master, two front-end and three back-end servers (one not in use---old, being
    > retired, running account creation scripts which need to be moved).
    >
    > Sendmail reports: "Deferred: Connection timed out with mail.rpi.edu."
    > And, occasionally it reports: "Deferred: Broken pipe." (mail.rpi.edu is a
    > vip. Port 25 connections are sent to one of four smtp machines via a Cisco
    > CSS director.)
    >
    > The 60 minute delay (in our case) was due to the MinQueueAge parameter in
    > sendmail. Once email was deferred to one of the smtp servers, that server
    > continued to queue email for 15 minutes (when the .hoststat is rechecked).
    >
    > The queue runners would skip the queued email for 1 hour. To patch this, I
    > put the local email in a separate queue group, and run sendmail out of cron
    > with MinQueueAge value of 10 minutes. (Putting a runner on the queue group
    > didn't work, since MinQueueAge takes precedence.)
    >
    > But, the base problem remains: For some reason lmtp is returning a 400-level
    > dsn.
    >
    > Perhaps related, or not, I have also noticed occasional delays connecting to
    > IMAP. They tend to cluster around 15 minutes before the hour. It got
    > particularly bad when students returned last week.
    >
    > Google turned up a mention of an error in mupdate which caused it to double
    > free threads when the maximum connections is reached. Indeed, there were
    > numerous "could not start a new worker thread" errors in the cyrus.log file on
    > the murder master. I doubled mupdate_connections_max to 2048 and the
    > problem is reduced. The delays are still there, but they do not last as long.
    > There are still a few 'could not start worker thread' errors. The process
    > involved restarting services on the master, which killed about 800 mupdate
    > connections. Currently there are about 26 mupdate connections.

    My /var/log/cyrus.log is empty. How do I raise the log level to see if I'm
    also having the same errors?

    Mike

    ----
    Cyrus Home Page: http://cyrusimap.web.cmu.edu/
    Cyrus Wiki/FAQ: http://cyrusimap.web.cmu.edu/twiki
    List Archives/Info: http://asg.web.cmu.edu/cyrus/mailing-list.html
    

  • Next message: Bron Gondwana: "Re: ...and a question (SHA1 UUIDs)"





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