[mjb]

The classic "Leases: an efficient fault-tolerant mechanism for distributed file cache consistency" (http://portal.acm.org/citation.cfm?id=74870) dating back to 1989 is a good read about these kinds of systems. It makes some interesting observations about the approach, and introduces the need for bounded drift.

I think antirez is saying "skew" here when "drift" would be more appropriate. The safety property appears to refer to the different in rates between clocks, rather than the difference in absolute values. That's a much more reasonable assumption, and is likely to be true even with very bad clock hardware over short periods of time.

Obviously the bounded drift assumption,

[antirez]

> The safety property appears to refer to the different in rates between clocks, rather than the difference in absolute values.

Exactly that, thanks for the correction, indeed the word I used is wrong, even if probably from the context it was understandable I was referring to drift I'm going to replace the term.