Spanner is Google's scalable, multi-version, globally-distributed, and synchronously-replicated database. It is the first system to distribute data at global scale and support externally-consistent distributed transactions. This paper describes how Spanner is structured, its feature set, the rationale underlying various design decisions, and a novel time API that exposes clock uncertainty. This API and its implementation are critical to supporting external consistency and a variety of powerful features: non-blocking reads in the past, lock-free read-only transactions, and atomic schema changes, across all of Spanner.
Exclusive: Inside Google Spanner, the Largest Single Database on Earth Wired BY CADE METZ11.26.126:30 AM [wired.com...]
Much like the engineering team that created it, Spanner is something that stretches across the globe while behaving as if itís all in one place. Unveiled this fall after years of hints and rumors, itís the first worldwide database worthy of the name ó a database designed to seamlessly operate across hundreds of data centers and millions of machines and trillions of rows of information.
Spanner is a creation so large, some have trouble wrapping their heads around it. But the end result is easily explained: With Spanner, Google can offer a web service to a worldwide audience, but still ensure that something happening on the service in one part of the world doesnít contradict whatís happening in another.