My current setting is 30 seconds. A client would like me to change this to 900 seconds. Does anyone see a problem with this?

Inactive sessions could be kept open way too long and bog down your server.

You can change it on a per-site basis, and not have it affect your entire server's php configuration.

900 seconds? You'd have to wonder what they were doing for that. Its a bit unusual.

I suggest you audit his scripts before allowing it. 900 seconds if it is a busy site, with lots of hits, and an inefficient script can kill your server.

That's 15 minutes, why do you need so long to run something? Read through the script, ensure it is not buggy as sprintserve stated.

That surely is going to overload your server ..

Well, anyways cant be done from php script itself??

ini_set( "max_execution_time", 900 );