I learned something new, recently. Sessions in PHP are blocking. At Amuzi, I try to keep the user from have to go to another URI, this way the music won’t stop. So I end up using a lot of Ajax. Some of this are concurrent. For instance, when a user click to add a music, one request is fired to fulfill that request and another one to search for similar music. The problem is that, on server side, the two requests won’t run simultaneously if they use sessions.
But PHP is relatively smart. Sessions usually are cookie based. So the requests are blocking just intra-user, not inter users. Request from user A can run simultaneously with request from user B. But two requests from the same user won’t.
There is no magic. To overcome this issue, you have to keep the session open just for as long as you have to. You can control this by using the PHP functions session_start and session_write_close.
Careful, php.ini can be configured to start session automatically on each
request. So you might have to call session_write_close on start up, or disable
this behaviour.
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