Hi Steve, To achieve mirroring, MySQL can be run in a master/slave replication ring with two servers (look up replication in the manual). That way you can split reads and writes over both servers and get better read performance, and also more resilience. The way to achieve transparent failover is to have a load-balancer such as LVS (http://www.linuxvirtualserver.org). You can have two (again for failover) 1U rackmounts running LVS - the hardware can be something as low as 486 class. The LVS takes connections and redirects them to each of the MySQL servers in round-robin fashion. If one of the MySQL servers dies, it will be taken out of the pool until it is back up again. The way replication works in MySQL, if one of the servers dies, the other server will keep a binary log which is used to catch the downed server up when it comes back online. The only drawback with dual-master configuration is that unique IDs cannot be guaranteed if generated from the database - for instance, if an INSERT is processed at the same time by both masters. Therefore, unique IDs must be generated in the client with the use of mutexes. Regards, Jason Saunders -- Choose a Free Mobile or Free Line Rental, and get Free Connection with Free Calls, Free Smartbox, International Roaming, No Minimum Contract! For information and to order click over to http://www.iwantafreemobile.co.uk --------------------------------------------------------------------- Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail <[EMAIL PROTECTED]> To unsubscribe, e-mail <[EMAIL PROTECTED]> Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
