Overly persistent MySQL connections

[Rick Stevens]

We're using IMP on a load-balanced set of mail servers under Linux.
The user database is on a totally separate MySQL server:

                 |<-----> Mail server <-------->|
    Internet <-->|                              |<----> SQL server
                 |<-----> Mail server <-------->|

The mailboxes are on an NFS server and the IMAP server has been
modified to authenticate off of a custom LDAP environment.  We are
NOT using IMP or Horde's LDAP mechanism.

We have been running into a bit of a snag insofar as the MySQL
server keeps spawning threads to support IMP, but never expires
them.  As a result, IMP stops responding (try to log in and it just
sits there), while the MySQL server has, oh, like 40 threads running
(and I've almost NEVER seen more than 5 threads with anything OTHER
than IMP).

Has anyone else heard of such nasty behaviour?  Did I mess up on the
SQL configuration?  Is this a known problem? (I've noticed that
there's no SQL disconnect in the IMP or Horde code).

Any help would be IMMENSELY appreciated.  Direct email is peachy.

Thanks, gang!

----------------------------------------------------------------------
- Rick Stevens, CTO, PublicHost, Inc.        rstevens@publichost.com -
- 949-743-2010 (Voice)                     http://www.publichost.com -
-                                                                    -
-   You possess a mind not merely twisted, but actually sprained.    -
----------------------------------------------------------------------