mod_authn_dbd - internal server error after certain idle time

[Danie Qian]

I am using mod_authn_dbd and mod_dbd to do authentication again a mysql 
database. Basically it works but after sometime I will get a internal server 
error. I checked the log this happens at apr_dbd_pvselect() line in 
mod_authn_dbd.c. So this looks like to me that apr_dbd_pvselect() is trying 
to re-use a connection that is closed by the mysql server side whose 
wait-timeout is set to 1200 seconds. my mod_dbd setting is this
DBDMin  1
DBDKeep 2
DBDMax  50
DBDExptime 60
My question is why the keepalive setting for 60sec doesnt work for me? How 
do I fix this without changing the timeout setting on the mysql server?


Thanks,
Daniel