15 January 2007
Lampson: Lazy and Speculative Execution
16
Lazy: Eventual
Consistency
nWeaken
the spec for updates to a store
oGive up sequential consistency / serializability
oInstead, can see any subset of the updates
▬Requires
updates to commute
osync operation to make all updates
visible
nMotivation
oMulti-master replication, as in DNS
oBetter performance for multiple caches
▬“Relaxed
memory models”
nThe
bet: Don’t need sync
oA big win in latency
nRep:
State = set of updates, not sequence