look at this question Minecraft server load balance? it suddenly occurred to me:
2016 Minecraft, can only be placed on one server;
so for World of Warcraft in 2006,
1. When many players are huddled in one area at the same time, how do you load balance and let all players see each other?

2. How to avoid the collective request timeout of players in the same area due to the large number of single-point visits?

3. Is there a downgrade plan?

4. How was the back-end architecture designed at that time? If you designed it in 2018, how would you design it

add:
what is the Angela door? It is probably that many players are huddled together like the picture in the picture (the picture is found on the Internet)