This preview shows page 1. Sign up to view the full content.
Unformatted text preview: g writes on A and B – what should be returned by a later read by C? Can a different value be returned to C and D? In the simple (single copy) model, we only know that the read or write was done somewhere in the window, but not where in the window. The result of two overlapping writes is indeterminate – but we know that if the system is linearizable/serializable, it should be consistent with some serial order. system can’t finish a write operation until all copies have been updated. Once the operation has finished: everyone must see the result of the write. Difference between serializability and linearizability serializability means every operation appears in the order that each processor issued it, and every operation appears on every processor in the same order, but the order may differ from the order they were done in real time. Specifically, this allows potentially conflicting operations to be done in parallel, provided we make sure that every node sees the same result. Operations appear as if they happened in some single sequential order. Serializability/sequential consisten...
View Full Document
- Spring '14