OK, so I\'ve got this totally rare an unique scenario of a load balanced PHP website. The bummer is - it didn\'t used to be load balanced. Now we\'re starting to get issues.
The easiest thing to do is configure your load balancer to always send the same session to the same server.
If you still want to use session_set_save_handler then maybe take a look at auto_prepend.
session_set_save_handler