SEATTLE—In its continued efforts to make Azure a platform that appeals to the widest range of developers possible, Microsoft announced a range of new features at Build, its annual developer conference.
Many of the features shown today had a data theme to them. The most novel feature was the release of Cosmos DB, a replacement for, or upgrade to, Microsoft’s Document DB NoSQL database. Cosmos DB is designed for “planet-scale” applications, giving developers fine control over the replication policies and reliability. Replicated, distributed systems offer trade-offs between latency and consistency; systems with strong consistency wait until data is fully replicated before a write is deemed to be complete, which offers consistency at the expense of latency. Systems with eventual consistency mark operations as complete before data is fully replicated, promising only that the full replication will occur eventually. This improves latency but risks delivering stale data to applications.
Document DB offered four different options for the replication behavior; Cosmos DB ups that to five. The database scales to span multiple regions, with Microsoft offering service level agreements (SLAs) for uptime, performance, latency, and consistency. There are financial penalties if Microsoft misses the SLA requirements. The company describes Cosmos DB as “schema agnostic,” performing automatic indexing of data regardless of how it’s structured and scaling to hundreds of trillions of transactions per day. Cosmos DB is already being used by customers such as online retailer Jet.com.