ADR-005: Raft Consensus for Clustering
Status
Accepted
Context
Need consistent state across cluster with <100ms failover.
Decision
Use Raft consensus algorithm via openraft crate.
Consequences
Positive
- Well-understood algorithm
- Strong consistency
- Production-ready implementation
Negative
- Requires odd number of nodes
- Network partition limitations
Alternatives Considered
- Paxos: More complex
- PBFT: Byzantine fault tolerance unnecessary
- Custom protocol: Too risky
Implementation
The Raft implementation provides leader election, log replication, and membership changes. See the cluster subsystem documentation for integration details.