My current setup:
1 Http Load Balancer
3 Apache Frontend Server
1 Mysql Load Balancer (Balancing reads across all three, writes go to master only)
3 Mysql Database Server (1 master, 2 slave)
All is good, but I have sudden scheduled bursts of traffic and need to scale up during these peaks. I'm thinking of moving to a simpler routine.
1 Http Load Balancer
n* Apache + Mysql Servers combined (1 of which contains the Mysql master)
Each apache server will read from it's local database but write to the master. This means to scale up all I will need to do is start another server and add it to the LB. Generally I need the same amount of Apache servers as Mysql.
Do you see any problems with this setup? I haven't seen anybody using this setup before so I am wondering what are the disadvantages.