How many physical machines required for load balancing?

Hi,

I currently have two web servers - one as a master server, and one in a totally different physical location that I backup data to, and is on standby should server1 go down.

So, my question is - is this enough for a MySQL (http://www.howtoforge.com/loadbalanced_mysql_cluster_debian) and Apache (http://www.howtoforge.com/high_availability_loadbalanced_apache_cluster) clustering solution? From the tutorials, it looks like you need 4 machines, whereas I only have 2.

Any help appreciated.

Thanks,

Leon

 

Have a look here: http://www.howtoforge.com/forums/showthread.php?t=4990&highlight=ultramonkey