Multi GTM environments
Hi, could someone give me a very quick overview of how to design GTM in a multiple data centre environment? For example - say we have 10 DC's and put a GTM in each of them, how does GTM function at this level? Does each GTM need a route to the other GTMs management interfaces? How is traffic load balanced at the global level - is it just a case of users automatically connect to their nearest GTM? How does GTM deal with DNS in this way? Does each GTM require it's own DNS IP address? Perhaps each GTM has site based DNS (i.e GTM.NYC, GTM.JAP etc).
Finally - what's the purpose of the GTM's having visibility of each other? If a DC is offline for any reason, surely traffic would be automatically redirected to an alternate IP, regardless of the state of GTM? Perhaps this is for site-wide failover or something, are GTM's put in duplicate (or N+1) on each site?
I appreciate these are basic questions, but I'm quite new to the design aspect and need a basic overview of where to start (I'm sure I can cope with the configuration points).