Did you read the first page? BigTable has no trnsanctions, and scales, but is a pain for apps that need consistency. Spanner adds transactions for apps that need it, at scale, charging a tax in the form of latency.
Using two different clock technogies per node (GPS and atomic!) and light speed networking helps make this manageable.
We read about this at work at google a few months ago in a reading group. (perks of the job) And we spent almost the entire time talking about the timestamps. It is perhaps the most important piece of this paper. Fault tolerant time is right.
Yeah, I've been doing research in distributed systems and the timestamp part of this paper is incredibly interesting to me. It's awesome that I might actually get to cite something more recent than Lamport.
