On 5/4/2011 12:43 AM, Simon Horman wrote:
Sorry, I've been a bit slow.
I got the email and I'll try and get to it soon.
Well I believe I have finally tracked down the problem. I took the
thoeries you gave me along with the suggestions the Panda Imap developer
gave me and tried to setup some testing. It took awhile but last week I
finally caught the problem and found a clue in the messages file. It
logged a failure in xinetd. If you recall I mentioned I was working on
RHEL5. It was actually a migration project from RHEL4 to RHEL5 and it
turns out there is a change in the way xinetd functions that impacts our
environment in particular. In the version of xinetd provided in RHEL5 it
includes some new (as compared to the RHEL4 version) keywords. One of
them is per_source and is limited to 10 connections per source ip a
second. For an imap service that gets all it's connections from a proxy
like perdition this just won't work. Of course you won't notice until
you load it up with at least half a dozen very active users but when you
do it will just terminate any additional connections. So I set
per_source = unlimited to get the previous behavior. After a week of
additional testing with double the number of users all seems well again.
Thanks for the insights, they did help me when more clues finally did
emerge.
thanks,
David
--
David Severance
Central Computing Services
Office of Information Technology
(949) 824-7552
sev(a)uci.edu