YugaByte DB is a transactional database management system that can scale up and down across multiple regions for planet-scale and geo-distributed applications. Offering both SQL and NoSQL in one platform, it supports distributed ACID transactions, auto-sharding, and auto-balancing. It provides compatible APIs extended from Redis API and Apache Cassandra Query Language (CQL), and SQL API which is compatible with PostgreSQL. Built on a customized version of RocksDB, YugaByte DB's storage engine, DocDB, is a log-structured merge-tree (LSM) based "key to object/document" store.
YugaByte DB's first public beta release came out in November 2017. It was developed by the former team that built and ran Facebook's NoSQL platform that supported a number of real-time applications. They left Facebook and found their own company, YugaByte Inc, aiming to build a database management system to unify the data layer for mission-critical applications. Companies like Amazon, Netflix, and Uber have lots of experts, so they manage to offer complex DBaaS platforms which benefit their app developers. However, for traditional enterprises and small startups, the data layer is still an unsolved problem. This is where YugaByte DB comes to rescue.
Multi-version Concurrency Control (MVCC) Optimistic Concurrency Control (OCC)
YugaByte DB uses MVCC for concurrency control. Although not clearly stated, it uses a variant of OCC to ensure atomicity. Under a distributed environment, it uses Two-Phase Commit with Early Acknowledgement. When a transaction wants to modify a number of rows, it will first write "provisional" records of each modified row to the target tablet storing the row. These records will not be seen by the client unless the transaction commits. If conflicts occur when writing these records, the transaction will restart and abort. In this case, the client will see a certain number of retries (restarts are transparent to clients). If no conflicts occur, the transaction will commit and notify success to client. After that, the "provisional" records are applied and cleaned asynchronously.
YugaByte DB offers the following three query APIs:
https://github.com/yugabyte/yugabyte-db
YugaByte, Inc.
2016
C, C#, C++, Go, Java, JavaScript, Python