session_start seems to be very slow (but only sometimes)

Question

For some odd reason, just today our server decided to be very slow during the starting of sessions. For every session_start, the server either times out after 30 seconds, or

Answer 1

Have you tried session_write_close(); ? This will disable write-ability in session variables but you can still read data from them. And later when you need to write a session variable, reopen it.

I have also suffered from this problem but this thing worked like a charm. This is what i do:

session_start(); //starts the session
$_SESSION['user']="Me";
session_write_close();   // close write capability
echo $_SESSION['user']; // you can still access it

Answer 2

Please check if you have correct memcache settings e.g. in /etc/php.d/memcached.ini

Answer 3

Each session is stored by apache as a text file.

When session start is use to resume an existing session (via cookie identifier for example) maybe a big session file (a Session with a lot of content inside) can be slow to be started?

If this is the case probably you application is putting to much data into sessions.

Answer 4

I ran into this problem too. It was answered here:

Problem with function session_start() (works slowly)

Sessions are locked by PHP while one script is executing, so if scripts are stacked under the same session, they can cause these surprisingly long delays.

Answer 5

I know this is an old question but I've just fixed this issue on my server. All I did was turn on the bypass cache for the domains in the cache manager in the cpanel.

My sessions were taking ages to start and close now they are instant.

Answer 6

I had the same problem: suddenly the server took 30 seconds to execute a request. I noticed it was because of session_start(). The first request was fast, but each next request took some 30 sec to be executed. I found that the session file in c:\wamp\tmp was locked by the first request for some 30 sec. During this time the second request was waiting for the file to be unlocked. I found out it had something to do with rewrite_mod and .htaccess. I disabled rewrite_mod and commented out every line in .htaccess and it works again like a charm. I don't know why this happend because I don't remember change any settings or conf on wamp.