There may be delay between what the servers do but they are eventually consistent.

Given
- 2 servers A and B
- 3 clients 1, 2 and 3, all listening to the same presence resource and initially online.
- user1 client1 connected to serverA
- user2 client2 connected to serverA
- user3 client3 connected to serverB

Scenario:
1) client1 looses connection (soft offline)
2) serverA publishes client1.client_offline to redis
3) redis distributes client1.client_offline to serverA then serverB
4) serverA starts soft client1.user_offline countdown
5) a little bit later, serverB starts soft user1.user_offline countdown
6) after 14.xx seconds, client1 sends client1.client_online
7) redis dispatches that to server A then server B
8) serverA receives client1.client_online before the timeout. Cancels the client1.user_offline timeout, dispatches client1.client_online to client2
9) **bad luck** serverB considers client1 fully offline, dispatches client1.user_offline to client3.
10) catching up, serverB receives the redis notification client1.client_online. Realises user1 does is unknown and dispatches noth client1.client_online and client1.user_online to client3.

What did the different users see ?
- user1 had tough connection problems and got disconnected almost 15 seconds.
- user2 saw that user1 lost connection for a while
- user3 saw that user3 lost connection then completely went offline. A *very* short time later, he saw user1 coming back online.