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<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB style='font-size:
10.0pt;font-family:Arial'>Hi,<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB style='font-size:
10.0pt;font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB style='font-size:
10.0pt;font-family:Arial'>Over the past few months we have noticed a steady
increase in the load on our 2 mail scanner servers and in the last few days
messages have been substantially delayed between being collected from the
inbound mailqueue to the outbound mailqueue. We are running mailscanner
version mailscanner-4.53.8-1 on centos running linux kernel 2.6.9-55 and
using sendmail 8.13 as the MTA and clamav as the anti-virus software and
spamassassin as the anti spam software.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB style='font-size:
10.0pt;font-family:Arial'>We receive approximately 30,000 messages each day
which are handled by a cluster of 2 servers via DNS round robin, the load on
both machines is steadily at about 5,5,5 with clamscan processes constantly
being at the top of the process list in terms of cpu usage. We are also seeing
log entries similar to this constantly appearing in the maillog.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB style='font-size:
10.0pt;font-family:Arial'>MailScanner[31171]: Commercial scanner clamav timed
out!<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB style='font-size:
10.0pt;font-family:Arial'>MailScanner[31171]: Virus Scanning: Denial Of Service
attack is in message l5Q7bntD008994<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB style='font-size:
10.0pt;font-family:Arial'>Both servers are high powered machines only running
the mailscanner software (xeon 2.8 cpu and 2gb ram in each machine)<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB style='font-size:
10.0pt;font-family:Arial'>Is there a reason that the load would be so high as
there’s not a huge quantity of email going through the servers for what I
would expect them to handle, or if there are any configuration tuning that can
be done in mailscanner to resolve this (we’ve fine tuned the time out
settings in sendmail to minimise message delays but this hasn’t lowered
the load or message delivery time)<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB style='font-size:
10.0pt;font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB style='font-size:
10.0pt;font-family:Arial'>Thanks for any help<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB style='font-size:
10.0pt;font-family:Arial'>Al<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
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