No Database Selected Error

whobutsb

Hi all,

I built a web application for our IT department to handle PC Cases. I used PHP/MySQL for the application. Everything for the most part works fine except every once and a while when you are navigating the pages I get a blank white page with the error "No Database Selected" in the top left hand corner. It seems like the database is timing out or something, or maybe its getting too many queries, I'm just not sure.

Just seeing if anyone has had the same issue and would have a solution. Is there a PHP script I could use that would keep querying the server even if it gets this error?

Thanks!

etully

Intermittent problems are the hardest to solve. Especially over a bulletin board where we can't see the system itself.

On the other hand, "too many connections" is a good guess and a good place to start because you can test that fairly easily.

Get some info on monitoring the health of MySQL. Check the number of connections when that problem happens.

We found that there were some conditions on our server that caused the machine to run out of RAM and when this happened, Apache slowed to a crawl, and when that happened, it was easy for 100 MySQL connections to open up so the error was very misleading. It was a RAM problem caused by a defective Perl script that made the whole thing look like a MySQL problem.

Truthfully, you're probably going to need a good sysadmin who is skilled at sniffing these things out.

whobutsb

I have access to our websites CPanel and PHPMyAdmin pages, where should I start looking for trouble and RAM usage? Or would I need to contact our host and see if its something on their end?

etully

That's outside of my scope of expertise, sorry. What I've learned is this: If you know a little programming, you can get by. If you know a little sysadminning, you know nothing. My rule is, leave sysadminning to the experts.