When an iD user saves data, the current graph and its history are cleared. A download of the same area immediately follows to load data from the API back in to the freshly-cleaned graph.

This all happens within a second or two of a successful diff upload, not giving much time for any replication that might happen to complete. Since the OSM API is looking to scale horizontally, replication delay will start to play a factor soon.

iD should consume the response from the server and apply it to the graph.

See also:

• @pnorman's dev@ thread
• my bug/pull request [WIP] Tiled OSM data #1396 that is my work on trying to cache OSM data and won't work because of this