PHP long polling, without excessive database access

Question

I\'ve always enjoyed the idea of long polling; on my development server I\'ve played with various notification / new post systems, each using javascript to hold a connection

Answer 1

If your specific problem is that you're trying to avoid notifying events through a database, you should probably be looking at using shared memory or semaphores.

Instead of continuously polling the database, you would instead monitor the shared memory. When something writes to the db (I'm assuming some sort of message queue), you can flag the event via the shared memory. The listening code would detected this, and only then establish a db connection to retrieve the message. Alternatively, you could use shared memory to entirely replace the use of the database.

The reference for the php semaphore and shared memory functions is here - http://uk.php.net/manual/en/ref.sem.php