[volunteers] Lists machine's stability: improved

Rick Moen rick at linuxmafia.com
Tue Jan 26 17:00:38 PST 2010

1.  Marc Merlin created and enabled a 2 GB swap file to supplement the
existing 512 MB swap partition.

2.  I upgraded SpamAssassin to the final package available in Debian 3.1
"sarge".  This latter operation was carried out by very carefully 
experimenting with /etc/apt/sources.list entries to find the highest 
upgrade point that could be reached without scary messages from apt
about needing to authorise its removal of the sysvinit package, replace
libc, etc.

These two changes seem to have warded off the system's bouts of
instability:  It's been up for two weeks without problems, since the
SpamAssassin upgrade.

Notably, before, there were always two or three spamd (SpamAssassin
daemon) instances that always ran with >150MB of RSS (resident set size
RAM usage), which I suspected of being the ones that eventually ran away
with _all_ system RAM, setting loose the kernel OOM killer, etc.  With
change #2, this appears to no longer be the case, and none of the spamd 
instances run much higher than the usual (if bloated) 25 MB size.

I also reduced the number of IP addresses from which Exim4 will refuse
mail from 2771 IP addresses to 3.  This probably doesn't help
performance a lot (because Exim4 rulesets are much, much faster and less
RAM-grabbing than SpamAssassin's), but couldn't hurt.  For one thing,
the notion of permanently banning individual IP addresses because
they've once spammed you is a losing game, and most of them are
dynamically assigned broadband/dial-up IPs anyway, so the spam-source
machine that has them today will have a different one tomorrow.

Last, I verified that the box is not affected by SpamAssassin's 2010
bug (http://lwn.net/Articles/368396/), because it has no
FH_DATE_PAST_20XX rule in /usr/share/spamassassin/* .  (Even with the
SpamAssassin upgrade mentioned in point #2, spamd is too old to have
that problem. ;->  )

rmoen at borgia:~$ ssh rick at lists.svlug.org
rick at lists.svlug.org's password: 
Last login: Tue Jan 19 19:54:26 2010 from uncle-enzo.linuxmafia.com
Linux svlug.svlug.org 2.4.26-grsec2.0-marc1 #1 SMP Sun Apr 25 10:04:32 PDT 2004
i686 unknown unknown GNU/Linux

The Web pages are in /home/httpd/html/ .

Edit with:
co -l about.php
vim about.php
ci -u about.php

But what you really want is "evim about.php", which does the above and more.

rick at svlug:~$ sudo bash
root at svlug:~# uptime
 16:38:56 up 13 days,  5:04,  1 user,  load average: 0.00, 0.01, 0.00
root at svlug:~# free
             total       used       free     shared    buffers     cached
Mem:        513336     508356       4980          0      51720      55560
-/+ buffers/cache:     401076     112260
Swap:      2578128      70276    2507852
root at svlug:~# ps -eo pid,user,command,rss | grep spamd | sort -rn -k 5
 9483 nobody   spamd child      27008
 8991 nobody   spamd child      26844
 9176 nobody   spamd child      26012
 9129 nobody   spamd child      25888
 8939 nobody   spamd child      24212
 9544 nobody   spamd child      24132
 9538 nobody   spamd child      24132
 9495 nobody   spamd child      24100
 9036 nobody   spamd child      24080
 9591 nobody   spamd child      24056
 9218 nobody   spamd child      24028
 9114 nobody   spamd child      24028
 9708 nobody   spamd child      24016
 9806 nobody   spamd child      23988
 9331 nobody   spamd child      23976
 9777 nobody   spamd child      23928
 9776 nobody   spamd child      23920
 9312 nobody   spamd child      23860
 9701 nobody   spamd child      23752
 9489 nobody   spamd child      23752
 9678 nobody   spamd child      23716
 9365 nobody   spamd child      23684
 9534 nobody   spamd child      23680
 9526 nobody   spamd child      23632
21193 root     grep spamd        916
 5669 nobody   /usr/sbin/spamd  8964
root at svlug:~# swapon -s
Filename                        Type            Size    Used    Priority
/dev/ide/host0/bus0/target0/lun0/part3 partition        530136  65880   -1
/var/tmp/swap                   file            2047992 4396    -2
root at svlug:~# cat /etc/debian_version 
root at svlug:~# dpkg -l | grep spamassassin
ii  spamassassin   3.0.3-2sarge1  Perl-based spam filter using text analysis
root at svlug:~# 

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