Hey,
Honestly, I do not know how the servers work, but I'm coming with an idea.
The idea is to split haven and the tiers from eachother placing both on a seperate server group. If a massive group of people decide to log on haven it means that the total feedback of what joins on haven does not work on those who already are in the dungeon. In other words, Haven functions as a sort of buffer to keep the people who are playing in clockworks itself more or less lagfree.
Not sure if it works, it's just an idea that might need some shaping.
One problem.... the game is hosted in Amazon's EC2 cloud. You have to think of it like a self storage warehouse. You rent X space (virtual servers) in a giant steel building (server farm). Inside your rooms you have boxes (instances). All of your instances has to fit inside the available rooms you rented. Optimally you want to use up all of the space you have to fit as many boxes as possible (players). So if you rent 2 rooms, but only keep christmas boxes (haven) in one room, and old tax papers (clock works) in the other, which fills up half a locker each, your wasting a lot of money.
But thats not your only problem. The storage place is constantly busy with people moving around, so you have to share walkways (network paths). On top of that, your building is all the way at the back of the storage lot, and theres no parking (Seattle). So you had to park on the street half a block down from the lot, then walk 2 blocks through the lot to get to the building with your storage locker (Level3). But now that your inside, you have to wait an hour because your sister gave your dead beat cousin Johny (Steam players) the combination to the lock, and hes now trying to put an old sofa in with your christmas stuff. BUT IT WON'T FIT.
So you say screw it, take some of your christmas stuff and put in the other locker so its 3/4 full. A week later, Johny's band start putting the rest of their crap (Steam helmet achivement/Star spangled bomber) in with the Sofa and now its completely full. So you have to put the new boxes you brought into the last locker and now its completely full too. So now you need to move your ATV out of the garage because they are repaving it for a week (new players). Johny and his pals have no money (people who can't pay for CE), your sister doesn't think its her responsibility (people who refuse to buy CE), and now you have your ATV complaining about how cold it is strapped to the back of your truck, and thinks that cutting the couch in half and turning it sideways will make the server not lag anymore.....
I don't know where I just went.... but I'm scared.