Session help

Anon

I'm using php sessions fine on windows 2000 server / iis5. My problem is that the session files aren't being deleted automatically. I have just had to delete 54,000 session files from my session directory. and it only took a week for these files to build up.
Previous to this, I didn't realise the files weren't being deleted and it caused my whole webserver to corrupt, requiring a complete reinstall of windows.
What is causing this - is it when a user does not log out? Or because of the file permissions I have on the session folder - I currently have the anonymous internet user account with modify permissions but not full control.
Can anyone please help?

[deleted]

"requiring a complete reinstall of windows"

just more proof that windows is not a production platform. A 'real' OS would just slow down or refuse to write more files in that dir. 🙂

read the PHP manual about the session.gc_probability and session.gc_maxlifetime settings in php.ini. THey define how long a session may survive, and how likely it is that starting a session will cause old session files to be deleted.

If the probability is set to zero, no files are ever deleted.

Anon

The probability is set to one, which is the default.

[deleted]

Set it waaaay higher. 75-90.

Right now there's only a 1% chance that the old session files are cleaned.
And make sure your session lifetime is reasonable, a few hours is more than enough.

Anon

That seems like a really bad idea. If the site has 10,000 hits a day, the session folder would be checked for old sessions about 9,000 times - which would be pretty much constantly - a big drain on resources I think.

[deleted]

"a big drain on resources I think."

Not really. All the file stats are in the filesystem's cache, so it's a matter of microseconds to run the GC.

Besides that I don't think you have much of an option: 'waste' some time running the GC, or re-install windows every week.

The rest of the world is not complaining about performance loss through running the GC, so why should you? 🙂

Anon

Well we\'ve managed to kill two birds with one stone. We use two identical webservers that are load balanced. We were having problems with a user logining on and their session only being created on one machine - if the next page they went to was on the other page they found themselves not logged on.
What we have done now is put in a custom session handler so that all the user sessions are stored in the mysql database that resides on just one of the machines.
- so there you go. Filesahring problem solved. Too many session files problem solved.

[deleted]

Nice one.

Ofcourse now you have to remember to clean the database out every now and then, or at 54k rows/week you'll soon get a very large table (and large + MySQL = trouble)

Anon

No problem. Old session are cleared out in exactly the same way as php does when it\'s using files - theres a 1% chance the garbage collection will be started with every new session (and of course it actually works!)