Spanner is a globally-distributed data management system that backs hundreds of mission-critical services at Google. Spanner is built on ideas from both the systems and database communities. The first Spanner paper published at OSDI'12 focused on the systems aspects such as scalability, automatic sharding, fault tolerance, consistent replication, external consistency, and wide-area distribution. This paper highlights the database DNA of Spanner. We describe distributed query execution in the presence of resharding, query restarts upon transient failures, range extraction that drives query routing and index seeks, and the improved blockwise-columnar storage format. We touch upon migrating Spanner to the common SQL dialect shared with other systems at Google.

Spanner is Google’s scalable, multiversion, globally distributed, and synchronously replicated database. It is the first system to distribute data at global scale and support externally-consistent distributed transactions. This article 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: nonblocking reads in the past, lock-free snapshot transactions, and atomic schema changes, across all of Spanner.

Two techniques for functional detection of local area incoming war dial are described. One technique employs a dedicated workstation looking for evidence of incoming war dial. We describe our experimental implementation of this technique, including alarm generation to a Cisco NetRanger(R) intrusion detection system. The second technique involves simple parsing of private branch exchange (PBX) call records for characteristic patterns of war dial. Baseline heuristics driving our algorithms are discussed. The non-terminated call detection limitations of this parsing technique for our Lucent Definity G3 PBX are discussed.