I have a PHP program that uses session variables to pass data over several PHP scripts. When I test it on my normal computer it flows just fine, and the session data holds through where expected, gets maintained on page refreshes, etc.
The strange thing I'm encountering is that on a secondary computer, the session is wildly inconsistent. I'll arrive at a page and it acts as if none of the session variables had been set. What's even stranger is, if I try reloading the page, sometimes the variables will actually load (and if I refresh again, they disappear again).
From what I can tell the problem doesn't seem to be browser-specific (I've tested on Chrome, Firefox and IE on both computers), but rather computer-specific, which seems really strange to me. I asked two other people to try it out, and discovered the exact same issue -- for one person the program runs just fine, but for the other person the session variables load inconsistently.
Any thoughts? I'm not doing anything fancy with the session, I just have the session_start() calls at the beginning of the scripts, post data via forms, and access/store via $_SESSION.
Edit: Some additional details --- in firebug, on the computer that isn't affected I'm seeing 3 cookies, which I guess I should be expecting (I'm admittedly not much experienced in session management and cookies). On the computer that is affected though, I'm not seeing any cookies at all in Firebug, even when the page does randomly load properly.
Also for clarification, I do expect the session data to be distinct for each computer, I'm not expecting data from one computer's session to be available on another computer's session.
Edit 2: I checked the cookies in firebug again, and it does seem like the 3 cookies are showing up on the affected computers (maybe it wasn't loading properly earlier today). I've done a var_dump of the $_SESSION variable on the pages that aren't displaying the data correctly, and sure enough all the information is there. It's just, for some reason it only sometimes loads in the HTML section below. I'll keep digging.
After a ton of digging around and testing, I finally figured it out, and the answer was surprisingly obscure and yet under my nose at the same time. My company uses VPN to tunnel remote desktops to our work servers. Although the pages I had set up on the work servers were accessible and worked properly via the browser (which is what threw me off), the session cookies weren't passing properly to the affected computers because those computers didn't have the site's IP address mapped to the work domain in their Windows hosts files. Once I mapped the IP address to the site domain, everything worked perfectly like my primary computer. Thanks to everyone who gave the issue some thought!
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I got a really strange problem in my PHP webapp.
If I log in, everything works fine for the duration of my session.
If I come in the next day, my webapp returns me to the Login page (as I expect).
The problem is that once I log in, parts of my site work and parts don't. The parts that don't return strange error messages and then I'm logged out and need to log back in. The strange thing is that some days some parts don't work and other days other parts don't work. If I delete all cookie values I can see, that doesn't solve the problem. The problem is only solved by deleting the entire cookie itself and then logging in again.
I've turned off garbage collection (because on Ubuntu there is supposedly a cron job which does it automatically even though I can't see it) but the issue was occurring before that.
So in terms of simplicity my intention is two-fold:
- To add code to my Login page to delete the cookie entirely (assuming I can do that from PHP)
- To move session storage from my webserver to my MySQL DB (because I'm in my dev environment but preparing to build my test environment which will be a cluster of webservers, not just one)
My questions are:
- Is there any way to ensure session values die reliably and gracefully rather than lingering and wreaking havoc?
- Is it possible to delete an entire cookie from PHP code, rather than just cookie values?
Many thanks.
After being a constant problem for a while, this issue has gone away. I've actually determined the cause and so I thought I'd post a quick update. Basically I had three sites I was accessing on my domain, my own webapp, a CMS Admin page and another admin tool. I've determined that the session cookies between my webapp and CMS admin were interfering with each other. If I use different browsers to access the different sites, the problem doesn't reoccur. It was driving me up the wall. Thanks to those who posted suggestions/responses. I appreciate it. I'll mark this as closed.
Somehow, when calling another script (all other scripts than index.php), all my CMS authorisation data gets deleted. The login boolean and username consists. This only appears using Chrome/Chromium.
The chrome developer tools don't show any errors, only 200 OK and 304 Not modified.
This is really annoying since I've changed to Chromium for Firefox being to ressource-heavy.
Any solutions?
Its going to be really hard to debug without any code or anything. When you say session data I assume you are referring to your php session. This has nothing to do with the browser. Are you making sure you aren't changing the domain/subdomain while browsing at all (which will cause you to lose your session). You can check your php.ini session settings but that shouldn't matter if it is working on other browser.
I'm guessing this is occuring because your session isn't getting started properly OR the session data is getting cleared somehow in your code.
Now it appears in Fx too. The problem: The hoster updated to PHP5 and there register_globals was set to On again.
I have a website (www.mysite.com) with a private backend (www.mysite.com/admin)
When I'm adding content to the site in the admin area and switch back and forth between tabs in the same browser window to see the content I'm editing, my session is getting expired/ended/terminated and I'm redirected to the login page again.
I have used the same code many-many times before on many web sites (this is a CMS I've made by myself) without a problem. The only thing I can think of is that this particular website is hosted on a different web server and maybe it's a matter of a php.ini setting or server configuration. Any ideas?
Have you checked your browser cookies? (the actual client-side ones?) or tried your luck with another browser? It may sound a bit strange, but I had a similar problem and in my case it had to do with these cookies. It may be worth figuring out because of your odd problem. As you might know the phpsession value is stored in that cookie and so is the domain.
Good luck!
This could be a result of several things, but my first instinct is to check and see if the session cookies are expiring very quickly. Sometimes server headers may change expiry values. You may also want to check the cache headers being sent by the server. If you are using asynchronous functionality on the admin area, it is possible that somehow the server is changing the expiry of cached files which could affect this.
I am eager to see the solution to this.
A few things to check:
session.cookie_lifetime setting - Possibly too short; 0 is the default and keeps the cookie until the browser closes
session.cookie_path setting - You'll want this to be '/'
Session storage - Make sure the session data is being written.
Explicitly call session_close() if your sessions are stored in a database. That will ensure they are written before your objects and database resources are destroyed.
If serving through any sort of proxy, check for any changed header information.
If caching, check your dynamic pages (requiring sessions) are being served by your web app and not the cache.
If testing with your local /etc/hosts, first clear your cookies so the new server's cookies are fresh and don't conflict.
Confirm in your browser that the cookie is in fact being stored. Maybe it's not actually coming back in the header.
I had a problem like this before. I was just uploaded a site from my localhost to a remote host, and I haven't change the nameservers yet. The hosting company provided me with a temporary url to be able to see my website. The problem was that this url was like this https://server_name.grserver.gr:8443/sitepreview/http/my_site.gr/, the result was that any browser didn't accepted the session cookie because I didn't had an SSL sertificate so the sessions didn't worked at all. I browsed a little the plesk panel and I found an other temporary url that was using http protocol, with this everything was ok. So if you are using https try to check if you have a problem with your ssl sertificate (for expample if it has expired). You said the problem occurs when you login in the admin page, do you switch then to https?
There could be several reasons. As there is no code or no details about the site provided , I am assuming that the problem might be if you are using htpasswd. If u are using htaccess authentication, then your session gets destroyed.
From experience, I can tell you a few things.
First, sessions need to be started with
session_start();
At the top of every page you want to use sessions.
Next, to save session data, you need to call another function to tell php that you are saving stored data. That function is
Session_write_close();
That function is needed on the bottom of the page when you are finished writing data to a session and want it saved for later use.
With those two combined, that should allow you to properly write to a session, save the data you entered into it, and access it later on your site.
Good luck.
The problem has been found after reading this topic.
I had a custom php.ini in the root dir and apparently it was interfering with the $_SESSION. I don't know why but after deleting it everything works fine.
At first it seemed as if the problem was opening pages located in different sub-folders in several browser tabs however it narrows down to a sub-folders issue and the fact that the $_SESSION wasn't accessible across them.
I'd like to thank everyone that put some time into trying to help me figure this out.
I've been trying to track down some annoying session issues since my webhost upgrade to PHP 5.3.3 awhile back. I've determined that if there is an active session, calling session_start() from a subdirectory kills the existing session. As an example, I start a session and a user logs in to domain.com/index.php then the user navigates to domain.com/members/ which fires start_session() ... the user's session is lost.
I've dug around for this and can't find anything similar. Is there a PHP configuration that would account for this behavior?
Calling session_start() multiple times with that version of PHP shouldn't cause any problems, however there are other possible causes.
One possible explanation is that the client's browser isn't sending the session id back to the server. You can test this out by comparing the session id that both pages produce. Assuming that you have a controlled environment where you can test this properly, you can use session_id() to get the session.
It might also be that the user is hitting a different webserver. Since (by default) PHP stores sessions to disk, there is no way for multiple servers to share the session information. If this is a shared host, it's probably quite unlikely this is the cause. You can test this out however by using phpinfo(). It should give you enough information to determine if it's the same server or not. For multi-server systems, I'd look at storing sessions in memcache or mysql.
if your sessions works all right within the same directory (it is unclear from your question), there is the only possible reason for such a behavior, a pretty obvious one: "directory" cookie parameter.
It seems it is set to somewhat unusual value, other than default "/" for the session cookie parameter.
You have to check it out.
Anyway, it is almost useless to try ANY session/cookie related problem without an HTTP interchange log.
You have to use some HTTP sniffer, like LiveHTTPHeaders Firefox addon to see what cookie header was sent by the server and which one was returned by client.
Otherwise it's all going to be shooting in the dark.
Okay, as it seems from your yonder comment, the session id remains the same, so, no HTTP issue can be a reason. The issue become a kinda tricky to spot.
Could you please post your test script here?
I've spent quite a long time searching, trying, testing for what looked like the same problem. As google kept sending me here, I think sharing the solution might help others (though I feel strange posting on a 2011 question):
Session variables set in /bar.php were not set in /foo/foobar.php.
It realised that the issue had nothing to do with folder/subfolder when I finally found out that the link in http://www.example.com/bar.php was pointing to http://example.com/foo/foobar.php (missing www).
Correcting the URL in the html link solved the problem. Having no time to dig deeper, what I can figure out is that (in my config) Apache makes no difference and serves pages indifferently with and without www, whereas PHP doesn't share the session between what it considers being two different domains, example.com and www.example.com.
Is there a PHP configuration that would account for this behavior?
Yes, if the storage for the session data differs between those calls, the $_SESSION content will differ as well. The storage can be configured, see http://php.net/manual/en/session.configuration.php for all configuration options you have with sessions.
Next to that if PHP is unable to read the session store, you will get an empty array as well.
I can't tell you if this is the issue with your problem, but probably it's helpful.
BTW, calling session_start() and than having an empty $_SESSION is commonly a sign that a new session has been created. You can verify this if you use cookies for your sessions and you output headers_listDocs:
echo '<pre>', var_dump(headers_list());
If it contains a new cookie for the session, the session has been created with this request.
Lots of good suggestions here. Thanks everyone. I spent a good chunk of the weekend digging into this and wasn't able to directly resolve it. I ended up demonstrating to my webhost that this problem happens on two of his hosted sites and doesn't happen in a default install of PHP. To work around the problem, I ended up moving all of my login and session logic into a single class.
Wanted to share another answer, found in this SO: Session variables not accessible in subdirectory answered by clayRay.
My answer was that I had a custom "php.ini" file saved in the root directory, and moving those directives into ini_set() calls solved it. You could also shove those over to .htaccess if your host allows.
I'm not exactly sure the question I should be asking. Sorry!
I'm working on re-doing my web site so as to be using PHP5. The server lives in a buddy's basement and I just ssh in to do my coding and view the pages just like any other page out there.
I keep track of login details in $_SESSION.
When I'm sitting at my home machine I can log into the site and everything is as I expect it in terms of the SESSION being available on all pages. When I log in on my work machine, I get a successful log in and can see the SESSION variables, but as soon as I go to another page the SESSION is gone as evidenced in session_id().
My previous web site built in PHP4 (and tweaked to keep PHP5 happy) does not exhibit this behavior allowing me to log in as expected at either location before and after the change to PHP5.
I guess I'm just looking for a clue as to what to explore next... Of all the puzzles I've encountered while teaching my self to code this one appears on the face, just crazy.
I think Jake is on to something about the cookies. Make sure your browser at work is set to accept cookies from that domain. Make sure there isn't any antivirus/antimal-ware that has disabled this. I'd use fiddler to watch the traffic and headers on your work machine, and your home machine. you should be able to quickly spot the difference since it sounds like a client issue.
It could be that the computer at work isn't supporting session cookies. It's been a while since I last read about PHP Sessions, but from what I remember...
session_start() is called.
php checks to see if the browser has sent a cookie to the server (a unique identifier needs to be supplied.
if so, it then checks checks on the server for a file with the name of the session id
if successful, it parses the file and sets the variables into the $_SESSION array
Notice that step one of this process is to actually start the session with session_start() this needs to be called before any output at all.
Have you got session_start() before output?
Do you make use of session_start() in your various php files ?
One way to get around this problem could be to store your sessions in a database.
This DevShed article by Rich Smith is a good place to start:
Storing PHP Sessions in a Database
The session is no longer saved as a file on the server, but rather an entry in the DB, and should solve any cookie issues.
Are the settings in php.ini for session.auto_start the same in both ini's?
See http://de3.php.net/manual/en/session.configuration.php#ini.session.auto-start