"Oh, I totally forgot to mention one iteration we did before coming to P2P solution. We had access to Amazon SimpleDB while it was still in beta. We did a "use a SimpleDB table as a shared memory" concept. That didn't work well. The problem with SimpleDB for this kind of situation is that read after write will not necessary return what you have just written. And delays were way to long for it to work, we were getting network partitioning all the time, so we were back to the drawing table. However we do use SimpleDB for some other parts of our system. Maybe we'll describe that in one of the future posts." - Andraž Tori