Which Clock: Monotonic for Spans, Wall for Stamps, Never Wall for Order

Which Clock: Monotonic for Spans, Wall for Stamps, Never Wall for Order A workflow diagram generated by Archify. 01 / Application need 02 / Clock choice EX / Misuse hazard Ask Apply What Do You Need? · span, stamp, or order? · Application need › Ask What Do You Need? span, stamp, or order? Measure Duration? · how long did X take? · Application need › Ask Measure Duration? how long did X take? Absolute Stamp? · hour for humans? · Application need › Ask Absolute Stamp? hour for humans? Cross-Host Order? · who wrote last? · Application need › Ask Cross-Host Order? who wrote last? Measuring Skew? · how do you sample? · Application need › Ask Measuring Skew? how do you sample? The Rule · spans mono, order never wall · Application need › Apply The Rule spans mono, order never wall Monotonic Clock · spans, timeouts, TTL · Clock choice › Ask Monotonic Clock spans, timeouts, TTL Wall Clock · display plus record only · Clock choice › Ask Wall Clock display plus record only Logical or Interval · Lamport, TrueTime wait · Clock choice › Ask Logical or Interval Lamport, TrueTime wait Hosts or Mock · independent, else MOCK · Clock choice › Ask Hosts or Mock independent, else MOCK Cross-Host Mono · meaningless compare · Misuse hazard › Ask Cross-Host Mono meaningless compare NTP Step Back · spans go negative · Misuse hazard › Ask NTP Step Back spans go negative Wall-LWW Burial · future stamp wins wrongly · Misuse hazard › Ask Wall-LWW Burial future stamp wins wrongly no yes: stamp only no yes: a span wall instead? burial hosts or mock rule it different zeroes steps it back no order needed yes: causal, TrueTime Legend Agent logic Policy Tool action Context / trace Cloud service External system