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From: Christian Purnomo (cpurncpurn.net)
Date: Sun Jun 27 2010 - 17:50:32 CDT
Subject: Re: performance tuning - relay
Date: Fri, Jun 25, 2010 at 06:21:01PM -0500
Quoting Stan Hoeppner (stanhardwarefreak.com):
: Can you provide some more specs on server2? IIRC you said you had a multidisk
: RAID array on serv2. What RAID level and how many disks? What filesystem?
: Are you running Courier with maildrop or the standalone maildrop with another
: IMAP server? What filtering, if any, are you doing with maildrop? Using mbox
: or maildir storage? IIRC you previously said you're BCC'ing _everything_ into
: a single mailbox (single address) on server2. Is this correct?
: And, lastly, was server2 in production for any amount of time before these
: problems occurred, prompting your post, or is this a new server that you just
: brought online?
All valid questions...
The real issue AFAIK was Server1 not feeding enough emails to Server2
and hence thousands of emails were queued on Server1 waiting to be
delivered to Server 2 via transport-relay. This was the major issue I
was trying to solve.
From your questions above, I could see where you're coming from that if
Server2 has performance problem then it would make sense to see the
queue built up at Server1. I can confirm server2 is very underload at
any time, the server is overspec'ed for what it is intended to do. I
can also confirm while those thousands of emails queued up at Server1,
Server2 was running smooth with 0.1-0.3 load average.
We have had server2 for about 4 years now and we have been having this
issues in the last 1 year where one of our new server happens to be a
mailling list which sends out thousands of emails to subscribers.
Anyway, Server2 spec is HP DL385G4, 4G RAM, 6 SCSI disks RAID 5 and
The delivery method on Server2 is maildrop - we use some mailfilter rule
to drop certain emails to certain folders. I can understand this is
adding some overhead for the local delivery on Server2 but this is the
cost I'm happy to take on. The queue can build up on Server2 and clear
up overtime without impacting our primary MX (Server1).