PHP4 session problem

Anon

Hi all,
I am running Linux/PHP 4.0.3/Apache but can't get sessions to work consistently.

Sessions works ok most times but frustratingly sessions sometimes stop working and the only way I've been able to get sessions to work again is to by rebooting the server.

I've tried tracing the trigger for the problem but there appears to be no consistency.

Has anyone experienced a similar problem or can offer a clue as what the problem is?

Is anyone currently using sessions with success on a production site.

Thanks in advance

George

Anon

We need a little more info than "it's not working"

What happens when your sessions top working?
Are you unable to do a session_start()? does it give any errors?
Is all the session_data empty?

and above all, can you give us an example of the code you use to work with sessions? (not all your code, just the bits that work with the sessions)

Anon

Apologies for the brevity.
The code is straightforward. All web pages are generated on the fly via a main.php which contains session_start() and session_registers about 20 variables before any headers are sent.

All works fine until something happens and sessions ceases to work. To test sessions I use a simple counter program which increments on each click. This shows that PHPSESSID is set and stays the same (no new sessions appear to be generated) but the counter does not increment.

Sessions is configured without cookies and I do not use the SID facility.

The session_start is currently on the main.php page which then includes a session.php which registers all the variables on each refresh. I've tested the program without the include (ie everything on the same page) but this makes no difference.

Once the sessions fail, the only way I can get sessions to start working again is to reboot the server.

Thanks for your reply and let me know if you need more info.

George

Anon

So you do not pass the sessionid from page to page in any way?

Anon

sessionid is passed either by a hidden field in a form or as part of the url

Anon

Does the session data show up in the tempfiles?

Anon

Good question. How do I look up the session data in the temp files? I can get to the tmp directory but all I can see is the session id number. I know there is a way to actually see the data but I've forgotten the actual command.

Anon

I guess you are on a unix system; use something like:

cat sessfile

more sessfile

Anon

Ok I can see the variables with this command. But at the moment sessions is working fine. I'll have to wait for the next seizure to see what is happening.

Any thoughts on what I could expect that might lead to the solution.

Are PHP4 sessions stable enough to run on a production site?

Many thanks for your help.

Anon

I take that back. Interestingly some of the old session info has not been garbaged and I've managed to find some of the sessions which crashed. The session data shows that some of the variables were updated but some were not.

Does this trigger any thoughts.

George

Anon

I'd try a slightly older version of PHP to see if it too fails doing this. Everything since the release candidates is moderately stable, and suitable for most internal use sites. (I've just retired my old 4.0RC1 server for a 4.0.2 server, so I'm interested in finding out if this is version dependent too:⁾

A few questions. When sessions stop working can you kill the web server along, and restart just that to get it back up?

'apachectl restart' may be enough to get it back on it's feet.

Anon

I haven't tried restarting apache but the reboot resolves everything.

I was hoping to avoid the overhead of storing variables in a database but from what I understand the difference in overhead may be marginal (given that sessions actually hard stores the variables (I think))

Any thoughts would be appreciated.

Anon

If you wanna use a database to store vars, then use mysql or gdbm files. gdbm files are super fast little hash tables you can use the dbm abstraction layer for.

Even if you data is in a database, you'll still need to have transparent sids propagation to keep track of your session ids. I wasn't sure if you said you had that turned on or not, but assumed you did, since no cookies usually means transparent sid propagation via get url syntax (?id=1234325).

Anon

I am currently using mysql for this site, how do gbdm files compare in terms of overhead?

In terms of sid propagation, at the moment it is turned on but in view of the problems I am experiencing I am thinking of turning sessions off totally and manually propagating the sids.