The performance of such a system really depends on what you can expect from it. If your system is distributed without full replication (and no overlap between

The performance of such a system really depends on what you can expect from it. If your system is distributed without full replication (and no overlap between nodes), then having offline nodes is easy - you just access to your local data, and the rest of the network can't access it. If you want to support full replication, or even partial, you'll want to detect (and maybe resolve) conflicts, and depending on how long you think a node can be offline, you'll need different mechanisms. If you expect nodes to be offline for really long periods of time, then you'll need to keep a lot of state around to be able to detect conflicts later - therefore making it perform worse (bigger latency while replicating data).