Transactions Across Datacenters (and Other Weekend Projects) - master/slave replication -- usually asynch -- weak/eventual consistency: granularity matters -- datastore: current -- this is how app engine “multi-home"s the datastore - multi-master replication -- one of the most fascinating areas of computer science -- eventual consistency is the best we can do -- need serialization protocol --- a global timestamp - 2 phase commit -- semi-distributed protocol: there is always a master coordinator -- ah! got an emergency call - gotta go - but this was the best talk ever…… :(