Mysql – load balancing MySql servers

1. For web load balancing, there are multiple solutions, opensource and paid, I personally have used cisco load balancers(CSM and ACE) and F5 and like them(but those solutions can get expensive). There are multiple for opensource, one that comes to mind is http://www.linuxvirtualserver.org/

2. For mysql load balancing, you can look at master to master replication for msyql. Look at: http://www.howtoforge.com/mysql_master_master_replication. What I have done in past for a project, I had 3 web servers serverfarm behind big IP(F5) and they all talked to one mysql server. And I had exact same setup in a different site, and both mysql servers had master to master replication. So users would use all the webservers and db servers and if one of the DB server, went down, web farm on that site would go down and users would only use the other site. (DNS failover and monitoring for multiple site monitoring and failover). You can use global load balancer if you have the budget to get more granular.

Remove the check port 9200s then your backup option should work. You seem to be mixing different examples, the mysql-check works on the standard port wheares there is another common example that uses an http check where they setup a xinetd process answering on port 9200 which runs a seperate check script.