Memory issues

[vivin1]

Hi there -

We have a PHP - Postgresql based ERP application. It runs on red hat 8 linux and uses Apache as the web server. I have some system memory related issues.

Every now and then when multiple users access different huge data access oriented features within the application, the system memory goes low and low till the time no memory is left at which point the applications hangs and I have to reboot the system. I keep checking the system memory using 'top' command. With every new user accessing different features within the application - I can clearly see that the memory goes low.

I am trying to follow 'good programming practices' like unsetting all the variables and other huge two-dimensioanl arrays at end of every script. But it seems to make no difference.

I am using persistent postgresql connections to the database - is that creating a problem ????

What is it ??? can anybody help me out ??

How do i release the memory back to the system ? Do i need to make any changes within httpd.cong, php.ini or postgresql.conf (config files) ?? Or is it that I have to follow some good programming priniciples ???

Your help would be greatly appreciated

Thank you
Viv

[dave420]

Don't use persistent connections, as each request to your server causes a new one to be created, which persists past the end of your script. So, after 5 requests, 5 connections are still open. That's rule #1. See how that works out, and get back to us if there's still weirdness.

Definitely using unset()s when possible helps things a lot, especially if you're tossing round huge amounts of data. Also, look into passing variables by reference, as that makes PHP pass a handle, instead of duplicating the variable (which, obviously, can have a huge impact on memory usage)