Stan Hoeppner wrote:
Eero Volotinen put forth on 11/30/2009 2:14 AM:
Quoting Ali Majdzadeh <ali.majdza...@gmail.com>:
Stan,
Hi
Thanks for your detailed response. Actually, the main reason which
drove us
toward performing virus scanning as an offline process was
performance. As
we deal with large amounts of e-mails, we found the way amavisd-new or
other
filtering management tools performing filtering too slow. We intended to
somehow decrease the amount of load which amavisd-new or similar tools
impose on the architecture.
There are many filtering Postfix AV solutions that are far more
efficient than Amavisd and many AV scanners that are considerably more
scalable than clamav such. A few years ago we did some detailed testing
between ClamAV and commercial av scanners and the difference was huge in
terms of load reduction and throughput. In our tests we have found that
the biggest performance limitation in Postfix for AV/AS scanning,
assuming you have removed bottlenecks that amavisd and clamav introduce,
is from having to copy messages out of the queue to scan. Some
commercial email platforms allow for scanning in memory rather than
requiring copying files and these platforms , in our test, far outscale
Postfix for filtering over a 100 messages/second.
Mike Katz
http://mailspect.com
You can set up easily smtp cluster for email filtering and scanning.
Agreed. But, due to the fact that the OP is sending from a Gmail
account, it's not possible for me to investigate his current MX setup in
DNS. Being able to do so would allow me to give more concise
information relating to his particular needs. That said...
Assuming he doesn't already have an MX cluster, scaling out with a DNS
based round robin MX cluster should do the trick. This will distribute
the entire inbound mail load (including virus scanning running on each
host) across X machines. Depending on the OP's mail stream, he may or
may not get (perfectly) even distribution across the MX hosts, but at
the least he will keep one host from being clobbered all the time. If
need be, increase X until a generally acceptable load across the hosts
in the MX cluster is found. If the OP is currently running a single MX
host, merely adding one more 'identical' host and doing the DNS
balancing act will likely solve the OP's load problem.
Short tutorial on DNS load balancing of MX hosts:
http://www.zytrax.com/books/dns/ch9/rr.html
Keep in mind that this requires identical Postfix configurations so all
the MX cluster hosts process all mail in exactly the same way--nexthop,
user lookup, filter rules, virus scanning, etc, must all be identical.
The only real differences will be the local host name and IP address.
Hope this points the OP in the right direction.
--
Stan
