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Unformatted text preview: see if their timestamp has exceeded yours. <Problem? If someone has already left for lunch, then no one else gets to go to lunch!> Another implementation: vector clocks. Vector clock: what is latest event I have seen from each process? VC[i] is the latest event at process i Pass vector clock in each message, and update local clock on message receipt (same as before, only element by element max). For all i, VC[i] = max (VC[i], msg-‐VC[i] + 1) VC defines a partial order for events, but can be used to enforce constraint that you don’t process an event until you’ve seen all prior events from each process. This helps with constructing consistent snapshots, a topic I’ll discuss next time. Snapshot is consistent if taken at the frontier of VC[i] – no events that depend on any that are missing....
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This document was uploaded on 04/04/2014.
- Spring '14