Message durability and quality of service across a large-scale distributed system

Ably is a distributed pub/sub edge messaging platform that ensures fault tolerance and superior messaging quality-of-service through four pillars of dependability. It provides regional and global fault tolerance, ensuring message availability and survivability even during network outages. The platform uses redundancy built into server clusters and design to ensure message ordering and exactly-once delivery. Ably also enables publishers and subscribers to recover gracefully following network disconnection.