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Re: Dozens of qmail-smtpd processes eating 100% of CPU

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Subject: Re: Dozens of qmail-smtpd processes eating 100% of CPU
From: Kyle Wheeler <kyle-qmail@memoryhole.net>
Date: Fri, 18 May 2007 14:05:42 -0600
Comment: DomainKeys? See http://antispam.yahoo.com/domainkeys
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User-agent: Mutt/1.5.15cvs (2007-05-02)
On Friday, May 18 at 03:09 PM, quoth Alex Kirk:
while (and a lot of CPU). Create those files and update them regularly (per the documentation that comes with the SSL patch), and it'll be *much* faster.

Here's my question: I have /var/qmail/control/clientcert.pem and /var/qmail/control/servercert.pem, but not dk512.pem and dh1024.pem. In fact, I'd never seen those two file names previous to today. Are you absolutely certain that I need files with those names, or would the ones I have work?

From the patch's documentation:

    when a 512 bit RSA key is provided in /var/qmail/control/rsa512.pem,
    this key will be used instead of (slow) on-the-fly generation by
    qmail-smtpd. Idem for 512 and 1024 DH params in control/dh512.pem
    and control/dh1024.pem. `make tmprsadh` does this.
    Periodical replacement can be done by crontab:
    01 01 * * * /var/qmail/bin/update_tmprsadh > /dev/null 2>&1

He says it's "slow", but what he meant to say is "glacially 'eat-your-CPU-alive' slow" (I've had this problem before on one of my servers).

and I am authenticating to my relay server. To be honest, I forget exactly which patch I used for that...I got it working very late at night after several hours of poking at it and trying different patches, and I was so confused by the time I finished I just threw my hands up and said "thank goodness it works!" Looks like I have a "qmail-remote-auth.patch" in my Qmail source directory, so that's probably it.

Mmm... yich. Well, if it works for you, cool. (It liked breaking on me.) It's probably got a few dozen little bugs in there, and possibly a security flaw or two---so if you have the time, I highly recommend looking into fixing it.

::Sigh:: I'll put it on my list. I'd love to fix it -- it's a horribly buggy patch -- but it may be a while before I find the time. Of course, if anyone reading this wants to pay me to fix it (the work would still be GPL/BSD/whatever open license it currently is), I'll prioritize it. ;-)

HEH. :D Yup, I a similar experience. I found a few bugs and submitted them back to Dr. Hoffmann (who is currently maintaining it), but after a while I gave up and found another way of getting my mail to relay (I didn't have a ton of free time to debug it).

Technically, if it works for you, then it's probably fine, as long as you trust the server you're relaying through.

No such luck. I've already had the mail client I'm using now configured to use TLS, so I turned on top and sent a message to the misbehaving server. No rogue processes at all -- I didn't even see a new qmail-smtpd before the message was delivered. So I'm pretty sure it's not just a STARTTLS thing.

Hmmm.... well, before I say things are conclusive, do that openssl check I gave you.

~Kyle
--
Of course it's the same old story. Truth usually is the same old story.
                                                  -- Margaret Thatcher

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