I have 2 mirrored, PHP-enabled webservers connecting to the same MySQL database. These servers are load-balanced through a Cisco Local Director which maintains no data persistency. The problem is basically that, though UPDATES and INSERTS on one of the webservers are immediately registered (through a SELECT statement) on the other box, only UPDATES on the second box are immediately registered on the first; INSERTS on this second box take some time (several minutes) to show up on the first box. The assymmetry here makes this an extremely beguiling problem.

To correct it, I have tried to get rid of persistent connections (both through php.ini and through our code). I have also tried upgrading MySQL (to 3.23.43); have upgraded (and backgraded to PHP 4.0.5); and have recompiled PHP (4.0.5) with the newest MySQL development libraries (again, 3.23.43). All of this has been to no avail.

The fact that direct client connections to the MySQL server from both of the webservers immediately shows any data updates seems to suggest that this is not a problem in the MySQL server itself. It would seem, then, that the PHP client is not directly contacting the MySQL server when it echoes out the stale data. Anyway, I'm pretty well stumped on this. Please let me know if this is in fact a bug (as it seems) or if there are any other things to look into.

Thanks,
jonathan