Hi. I'm needing some help on how I can improve my app's availability.
I'm a total noob when it comes down to networks, so If you could give me a few simple tips on how I can solve this I would appreciate.

To put it simple:
I have 3 machines (all with Ubuntu Server installed).
1 of them has HAProxy installed which receives all the users requests then load balances them by using round-robin algorithm, spreading the requests to my other 2 machines that have installed common ubuntu webservers.

Something like this:


My problem is that if my HAProxy goes down or fails, for whatever reason, my app will become immediately unavailable because all requests go through HAProxy first before reaching the webservers.
I'm not looking for a super fancy complex solution that guarantees me 100% 24/7 uptime..
Just something that allows my app to keep running if my HAProxy fails.

Using a virtual IP address seems to be the way to go. http://www.howtoforge.com/high-avail...at-debian-etch

...additionally: the IP address should be advertised using anycast, add a second HAProxy and duplicate your setup in one or more (globally dispersed?) data centres.