A general thanks to aphyr for exploring all of these kinds of issues in distributed datastores at a level where someone without a lot of database knowledge can understand and reason through. If anyone hasn't read his Jepsen series and is interested in these kinds of things, it is well worth a read.<p>Of course, I wouldn't read it if you store very important data in any of the datastores he talks about, you might be scared to learn how your system actually operates =).<p>P.S. - The Spanner link is broken, you have some invisible character being added to the end, gets encoded to %E2%80%8E
A little surprising that this article does not mention HBase which uses timestamps as part of the persisted key, while using an entirely different concept of a "WriteNumber" as an internal ID to resolve conflicting updates (MVCC).<p>This presentation might provide a helpful overview: <a href="http://www.slideshare.net/cloudera/3-learning-h-base-internals-lars-hofhansl-salesforce-final" rel="nofollow">http://www.slideshare.net/cloudera/3-learning-h-base-interna...</a><p>The relevant discussion starts at Slide 16
So last time the leap second issue came up, I learned that it's an "issue" because (as this article mentions) POSIX defines one day as exactly 86400 seconds. That's clearly incorrect; why do we still want to keep that definition around?