Re: Advice Required - for avoiding conflict betwen qmail-smtpd, rblsmtpd loaded as shared objects in tcpserver

Erwin Hoffmann <[email protected]> Sun, 2 Apr 2017 00:02:23 +0200

Newsgroups	gmane.mail.qmail.general
Message-ID	<[email protected]>

Hi Manvendra (and all other readers),

> Am 31.03.2017 um 19:05 schrieb Manvendra Bhangui <[email protected]>:
> 
> In recent past I worked on an idea that I had
> to eliminate the frequent fork() / exec()
> calls made by tcpserver for incoming emails
> 
> Summary
> -------------
> 1. the entire smtpd code was written as a function smtp_init()
>    and compiled as /usr/lib/indimail/plugins/qmail_smtpd.so
> 2. the entire rblsmtpd code was written as a function rblsmtpd()
>   and compiled as /usr/lib/indimail/plugins/rblsmtpd.so
> 3. wrote a function load_shared() for tcpserver which is just
>    a 40 line function using dlopen(). To avoid messing up
>   this email link to this function is here
>   https://sourceforge.net/p/indimail/code/ci/master/tree/ucspi-tcp-0.88/load_shared.c
> 

actually, Charles spoke out what is common believe: Fork/Exec is an operation to lightweight to invest a lot of efforts to improve it. In particular considering the benefits of an uncompromised and clean environment (unlike a thread). HW multithreading (lots of CPUs) will again be in favor of this decision.

I'm also not so positive regarding shared modules in qmail. Clearly, an entire new architecture paradigm should be substantiated with numbers and profiling is certainly necessary. However, I don't see (though without numbers by myself) a great need to change qmail's internal working structure; in particular regarding portability.

Currently, Kai Peter (eqmai) and me (s/qmail) are going to bundle our activities to focus on an 'alternative' qmail to feed the need for a concurrent and stable replacement for qmail. We've had this discussion months ago, and I rather invite you to participate again (let's do that off-line).

Regards.
--eh.

Dr. Erwin Hoffmann | FEHCom | http://www.fehcom.de | PGP Key-Id: EE00CF65

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