[Mailman-Developers] (no subject)

[Brad Knowles]

At 3:18 AM -0700 2004/04/15, Somuchfun wrote:

>  2. Using a dual xeon 1.8 server with 2GB of ram I still have the problem
>  that the web interface is not responding when sending out a message. Looking
>  at the cpu and memory stats it seems mailman grabs all resources and leaves
>  the web interface unusable. This has gotten so bad that people complained
>  that they cannot unsubscribe after receiving the message.

	This is a known performance issue with some large lists.  I don't 
know what kind of disk subsystem you have, but if you can use a RAID 
0+1 array with high-speed disks on an intelligent hardware controller 
with battery-backed write-back cache, and you enable certain 
filesystem features (depending on your OS), this may help 
significantly improve your performance.

	In my experience, most performance problems with large mailing 
lists and large mail systems come down to inadequate disk I/O 
capacity (operations per second, not read or write throughput), and 
doing this kind of thing is the best/most reliable way to get the 
kind of performance you're likely to need.  You don't need CPU for 
this.  Once you get a certain amount of RAM, adding more isn't likely 
to help you very much.  What you really need is a robust and 
killer-fast disk I/O subsystem.


	See the archives for more information on this subject, and also 
Mailman FAQ entries 
<http://www.python.org/cgi-bin/faqw-mm.py?req=show&file=faq04.011.htp>, 
<http://www.python.org/cgi-bin/faqw-mm.py?req=show&file=faq04.012.htp>, 
<http://www.python.org/cgi-bin/faqw-mm.py?req=show&file=faq02.002.htp>, 
<http://www.python.org/cgi-bin/faqw-mm.py?req=show&file=faq06.006.htp>, 
and 
<http://www.python.org/cgi-bin/faqw-mm.py?req=show&file=faq06.008.htp>.

	Then, depending on whether you use Exim, Sendmail, Postfix, or 
Qmail, see 
<http://www.python.org/cgi-bin/faqw-mm.py?req=show&file=faq06.002.htp>, 
<http://www.python.org/cgi-bin/faqw-mm.py?req=show&file=faq06.003.htp>, 
<http://www.python.org/cgi-bin/faqw-mm.py?req=show&file=faq06.004.htp>, 
or 
<http://www.python.org/cgi-bin/faqw-mm.py?req=show&file=faq06.005.htp>, 
respectively.

	There's lots of good extra stuff mentioned at the top of 
<http://www.python.org/cgi-bin/faqw-mm.py?req=show&file=faq06.003.htp>, 
so even if you use an MTA other than Sendmail, I recommend that you 
check out this entry.

-- 
Brad Knowles, <brad.knowles at skynet.be>

"They that can give up essential liberty to obtain a little temporary
safety deserve neither liberty nor safety."
     -Benjamin Franklin, Historical Review of Pennsylvania.

   SAGE member since 1995.  See <http://www.sage.org/> for more info.