The servers of decentralized exchanges are normally spread out. This is different from centralized exchanges that normally have their servers more concentrated.This spread out of servers leads to a lower risk of server downtime and also means that decentralized exchanges are virtually immune to attacks. This is because if you take out one of the servers, it makes little to no difference for the network of servers in its entirety.However, if you manage to get into a server at a centralized exchange, you can do a lot more harm.