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@HenryR | |||||
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This paper that improves clock synchronization accuracy to tens of nanoseconds is amazing work.
What changes with that level of accuracy? Like the paper says, Spanner commit times get a lot shorter. But is it now safe to take action without coordination?
usenix.org/system/files/c…
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Henry Robinson
@HenryR
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23. sij |
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One of the classic examples is leader failover: when is it safe for a replica to start serving? We only have to wait to be sure the original leader had realised it’s stopped getting heartbeats. So theoretically a tighter clock sync makes that wait time shorter. But...
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Henry Robinson
@HenryR
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23. sij |
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my guess is that other factors, like scheduling delays, dominate in this case and contribute to potentially significant variance before a leader realizes what’s up. Putting the clock check on the critical path mitigates this at the expense of lots of clock checks.
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☭🐇
@palvaro
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23. sij |
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henry is this a rhetorical question or...? do I need to read the paper right now?
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Henry Robinson
@HenryR
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23. sij |
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I mean Heidi thinks she might be out of a job, so calibrate your threat level accordingly: twitter.com/heidiann360/st…
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Carlos Baquero
@xmal
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23. sij |
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It’s a very nice paper that advances the tightness that can be achieved with clock synchronization. Don’t think by itself it makes agreement and durability obsolete.
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Henry Robinson
@HenryR
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23. sij |
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I agree in the strict sense, but I wonder how close we are to practically being able to appeal to probabilistic arguments about the chances of A and B having observed the same instant.
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Bill de hÓra
@dehora
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23. sij |
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unroll plz @threadreaderapp
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Thread Reader App
@threadreaderapp
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23. sij |
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Bonjour, the unroll you asked for: Thread by @HenryR: This paper that improves clock synchronization accuracy to tens of nanoseconds is amazing work. What… threadreaderapp.com/thread/1220166…. Talk to you soon. 🤖
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