Re:You Can't Sacrifice Partition Tolerance
by Deestan on Friday October 08, 2010 @05:37AM
(#1771102)
I take this to mean that if the nodes are disconnected from each other, Synctus disallows all access to certain files on node A; i.e. the files that node B currently owns.
Do I understand correctly?
Yes, that's right. Although currently it provides read-only access if a replica (not necessarily known to be the latest) is available, so I suppose that's not quite fully C in the read-only case. In the future, this might be a configurable option.
Although it is pretty much the only choice for general purpose file sync, it's still not a good choice. It is difficult to train non-technical staff to deal with inconsistencies on resync, and they don't want to have to deal with it. I've had success with Synctus precisely because it guarantees consistency (it is CP, and any one node keeps the A for a given file). Of course, this only works for mostly-on systems.