mysql user connections problem

[محروم.كوم]

Hello,

I have problem with max user connections. Yesterday my site was down for 15-20min and I got 2000 emails about error. I had that problem before and I was increasing connections but problem is still there. Yesterday I put that number to 300 and I think it is to much even I have strong server ( i7 - 12 GB RAM ).
I have contacted my host and they said:

You may want to look into the code side of things to determine why this user needs so many database connections. Usually, it's because the application is not closing it's connections once it's received data from the database, so they are just sitting open wasting them. Also, sometimes a poorly written query can lock a table and other queries will pile up behind it waiting for access to the locked tables.



Where should I search to locate this problem?

Thanks __DEFINE_LIKE_SHARE__