I have a website, I want to host on two diffident very far deployments. I have a rather good connection between them. But the users have a good connection only to what's near them.
My Idea is to duplicate the database servers, but I need complete consistency between them, I.E. a transaction should be considered complete only after committed on both machines.
How can I achieve this? any ideas will be appreciated, clustering, replication, etc.
Your idea already makes no sense to start with, unless ou have TWO websites, not one (i.e. two domains). DNS will not care about where your sites are, so users will get distributed randomly. And with your setup you do NOT have the possibility to rediret them (which would require an AS and then the use of an Anycast architecture).
As a result, half the users go to the wrong server. End of game.
But the users have a good connection only to what's near them.
How do you know. This is internet. Often major countries are easier to be reached than the small one in the neighborhood.
If you HAVE to do it, forget clustering. Go with replication. Painfull to develop, but your only choice. I see this more an excercise in wasting time, though, as you dont have the means to even make sure users go to the correct server.
