Ensuring Atomicity: A Tale of Dragonfly Transactions

Dragonfly is a multi-threaded data store that uses shared-nothing architecture to manage I/O operations and execute data operations in parallel. It addresses the problem of thread synchronization by dividing the dataset into smaller sections called shards, each managed exclusively by one dedicated thread known as a shard-thread. Dragonfly's transactional framework is based on the very lightweight locking (VLL) algorithm, which ensures atomicity and serializability for complex multi-key operations. The system uses intent locks to declare future intentions of acquiring control over resources, allowing transactions to execute out-of-order and reducing unnecessary congestion. This sophisticated yet accessible transactional framework makes Dragonfly an outstanding choice as the backend store for background job processing systems like BullMQ and Sidekiq.