Since you feel that you should never have more than 15 simultaneous
connections at a given time, I don't think modifying max_connections
will help. I would first verify that the PHP code is closing the
connection. If it isn't, then the connection will stay open until it
times out. If you do, however, decide to modify some of the
configurable mysqld parameters, then take a look at chapter 12 of the
manual, the optimization one. It mentions some sample configurations
for various levels of machines.
I'd recommended scheduling a script to run every x minutes/hours that
would capture what connections are established. A `mysqladmin
processlist` should give you information about all open connections.
Example output:
1000 $ mysqladmin processlist
+------+---------+--------------------+------------+---------+-------+-------+------------------+
| Id | User | Host | db | Command | Time |
State | Info |
+------+---------+--------------------+------------+---------+-------+-------+------------------+
....
Good luck,
Erik
