Hello all,
I'm running into a intermittent and very annoying problem with all of
my servers. I'm currently running FreeBSD 4.11, exim-4.51-0, and
mySQL 4.1.13. My exim config is setup to have exim do a mySQL lookup
in order to determine whether a given user's e-mail is hosted by our
e-mail servers.
Periodically, Exim throws the following error into its panic log:
Feb 9 13:24:51 mx_server_1 exim[69953]: 2006-02-09 13:24:51 failed to
expand "${lookup mysql {select distinct domain from email_table where
domain='$domain'}{$value}}" while checking a list: lookup of "select
distinct domain from email_table where domain='bob.com'" gave DEFER:
MYSQL connection failed: Can't connect to MySQL server on
'127.0.0.1' (61)
(where bob.com is one of our customer's domains that we host.)
This has been happening for months, and I'm trying to get rid of
these errors. The come in bursts - in a single second, I could get as
many as 30 to 40 of these messages.
Now, I've taken a few different steps to track this down, but the
problem is very elusive and hard to replicate. The mySQL error logs
are unhelpful. I'm sure that my mySQL server isn't running out of
connections, because if it was, I would receive a "too many
connection" error message. (I deliberately lowered the max number of
mySQL connections to test this.)
I'm wondering if there's a system level limit that I'm running into
that would be independant of exim or mySQL's configuration. I'm a
little hazy in this area, but I would be talking about some sysctl
variable, a ulimit on open sockets, or something to that effect.
I'm rather stumped on this issue, so if anyone has any suggestions or
hints on what might be causing this error or where I might start
looking to find the root cause of the problem, I would be very grateful.
Thanks,
Michael Jeung
