Scaling Raft

ScyllaDB is a distributed, eventually consistent database compatible with Cassandra. Starting with Scylla 5.0 it began adopting Raft: a strongly consistent, quorum based protocol, for many of its features.

Scylla uses Raft to manage cluster-wide information as well as individual data partitions. Large scylla clusters can have thousands of shards and hundreds of thousands of independent data partitions, each served by its own set of replicas. In this talk, Konstantin will discuss the challenges of supporting hundreds of instances of the Raft protocol on a single node and how we were able to significantly reduce the static burden on the network and disk each Raft group creates by sharing the work of failure detection and persistence between multiple groups.