Re: SRS implemenation in sendmail

Tom Lahti wrote:

>> When perl 5.8.0 was released, it leaked memory like crazy,
>> especially using ithreads. It is better in 5.8.4, but remains an
>> issue. There are, as far as I can tell, no identifiable, obvious
>> places in spf-milter where memory is not freed where it should have
>> been. All private per-connection data gets destroyed at
>> close_callback: $ctx -> setpriv (undef); it may very well be that
>> Sendmail::Milter itself leaks the memory.
>
> I was thinking possibly a package that you used in the code, i.e.
> Sendmail::Milter or Mail::SPF::Query, but I suppose its more likely
> perl itself.

I am pretty sure Mail::SPF::Query is not the culprit. With Sendmail::Milter
it is really hard to tell whether it leaks the memory itself, or whether
Perl running ithreads causes it.

Perhaps I should start looking into Sendmail::Pmilter. It is a
Sendmail::Milter API emulation without requiring that threads be used.  It
offers fork-on-request ("postfork") and child-pool ("prefork") means of
dispatching requests to the protocol engine. The author emailed me about it,
relatively recently; yet I have not gotten around to checking it out. The
longer I think about it, the more I like it, though. :) A nice pre-forked
PMilter model would be much better than having to use the leaky ithreads
(plus, that if anything were to go wrong, in terms of internal errors, only
the child would die).

>>> The second thing is it dies periodically.
>>
>> This has not yet happened to me; you are the first to report this.
>> So I cannot comment on why this would occur.
>
> What kind of volume do you process?

Less than you. Around 40,000 emails a day; 21,000 of which comes from
dynamic IP space (or RBL early-out); another 13,000 is marked as spam by SA;
and around 1,200 are fake DSN messages.

> I suppose it might be that I'm
> currently running this on Fedora Core 1, which has funky Redhat gcc
> stuff (which was used to compile sendmail and milter libs).  I have
> been thinking of switching the mail server to Debian.  What do you
> run it on?

I run it on FreeBSD 4.9R, gcc version 2.95.4. That is a known, stable
platform (no gcc issues). Apart from slowly leaking memory, spf-milter has
never died on me yet.

- Mark

        System Administrator Asarian-host.org

---
"If you were supposed to understand it,
we wouldn't call it code." - FedEx