You can only request server change (via ticket etc.). IB staff will process it over weekends only. You can't switch server when the server is down.
Its not one server adx. There is a server farm with sophisticated coms gear to direct your logon, data queries, orders etc to the appropriate point (so when u request HK homed data you'll see that your query is actually answered from HK not the US). Unfortunately such sophistication occasionally faults and when it does the problems can be very hard to find and fix (personal experience from a previous lives). I suspect that's what IB has been facing this week and their suppliers havent been able to resolve the issues quickly.
There is near zero redundancy here. I have several accounts... And it's always one "pink" and down... with the others running normally. IB could double their systems staff for $10-20 million/year... And their profits would go from $500,000,000 to $480,000,000... That that would be UNTHINKABLE. It's much better to just lie to people... And tell them to roll back their Java version.