High mysqld load

[Bjorn Swift]

Dear listmembers.

I am running IMP RELENG_3 and Horde Framework RELENG_2 on a FreeBSD 4.5-RC
box. My webserver is Apache/1.3.22 (Unix) PHP/4.1.1 and the mysqld is
3.23.39 - installed from ports.

A few times now I have noticed that mysqld tends to hang at 100% cpu.
Mysql's 'show processlist' returns something like this.

+-----+----------+-----------+-------+---------+------+-------+-------------
-----+
| Id  | User     | Host      | db    | Command | Time | State | Info
|
+-----+----------+-----------+-------+---------+------+-------+-------------
-----+
| 420 | hordemgr | localhost | horde | Sleep   | 1348 |       | NULL
|
| 547 | hordemgr | localhost | horde | Sleep   | 1845 |       | NULL
|
| 548 | hordemgr | localhost | horde | Sleep   | 1328 |       | NULL
|
| 567 | hordemgr | localhost | horde | Sleep   | 2164 |       | NULL
|
| 612 | hordemgr | localhost | horde | Sleep   | 506  |       | NULL
|
| 616 | hordemgr | localhost | horde | Sleep   | 1342 |       | NULL
|
....
....

Mysql's error log includes lines like these:

020211 16:46:52  Aborted connection 322 to db: 'horde' user: 'hordemgr'
host: `localhost' (Got timeout reading communication packets)
020211 16:46:52  Aborted connection 458 to db: 'horde' user: 'hordemgr'
host: `localhost' (Got timeout reading communication packets)
020211 16:46:52  Aborted connection 316 to db: 'horde' user: 'hordemgr'
host: `localhost' (Got timeout reading communication packets)

The only way out of this "loop" is to stop/start the mysqld.

Has anyone seen behaviour like this? The mysqld is hardly doing anything
else than serving Horde (two small databases) so this is my guess so far. Am
I perhaps looking in the wrong place?

As of now I am compiling mysqld 3.23.48 with the debugging option to try to
track the problem.

Thanks for your time,
Björn Swift