Byzantine Fault Tolerant State Machine Replication in Any Programming Language

Abstract

State machine replication is a fundamental primitive in fault tolerant distributed computing, but few production tools exist to support the replication of arbitrary state machines. The tools that do exist, like Apache Zookeeper, CoreOS's etcd, and Hashicrop's Consul, include an implementation of a consensus algorithm (eg. ZAB or Raft) for replication, and a service-discovery oriented key-value store as the state machine. While these tools can tolerate crash failures, they cannot tolerate malicious or adversarial ("Byzantine") faults. We present Tendermint, a production-grade Byzantine Fault Tolerant State Machine Replication engine written in Go. Tendermint supports replication for state machines written in any language by using a socket protocol to communicate between the state machine and the replication engine. Tendermint is being used on the public internet today to secure upwards of 1 Billion USD in value, with deployments supporting hundreds of consensus nodes. In this workshop, we provide an overview of the Tendermint system and demonstrate how to build Byzantine Fault Tolerant applications in Go and Javascript. We will also introduce the Cosmos Hub, an advanced Proof-of-Stake cryptocurrency system built on Tendermint.