https://mikelle.github.io/tags/consensus/Recent content in Consensus on Mikhail WallHugo -- gohugo.ioen-usWed, 04 Mar 2026 00:00:00 +0000https://mikelle.github.io/blog/cometbft-geth-consensus/Wed, 04 Mar 2026 00:00:00 +0000https://mikelle.github.io/blog/cometbft-geth-consensus/Part 4 of the Custom Geth Consensus Series The Redis-based system from Part 3 tolerates crashes: if the leader dies, a standby takes over. But it can’t handle a malicious leader that proposes invalid blocks. This article replaces the entire custom stack with CometBFT (formerly Tendermint), giving us Byzantine fault tolerance, multi-validator voting, and instant finality. Full source code is on GitHub. What We’re Building Each validator runs a CometBFT node paired with a Geth instance.https://mikelle.github.io/blog/redis-distributed-consensus/Mon, 09 Feb 2026 00:00:00 +0000https://mikelle.github.io/blog/redis-distributed-consensus/Part 3 of the Custom Geth Consensus Series A single-node consensus layer (Part 2) works until the node dies. This article adds Redis-based leader election for failover, PostgreSQL for durable payload storage, and member nodes that sync blocks from the leader and execute them on their own Geth instance, making each member a full execution replica. Full source code is on GitHub. What We’re Building ┌─────────────────────────────────────────────────────────────┐ │ Leader Node │ │ ┌──────────────┐ ┌────────────┐ ┌───────────────────┐ │ │ │ BlockBuilder │ │ PostgreSQL │ │ HTTP API (:8090) │ │ │ │ + Geth │-->│ payloads │<--│ /blocks?https://mikelle.github.io/blog/single-node-consensus/Sun, 08 Feb 2026 00:00:00 +0000https://mikelle.github.io/blog/single-node-consensus/Part 2 of the Custom Geth Consensus Series Part 1 left us with raw Engine API calls that build and finalize a single block. This part wraps those calls into a production-ready application with retry logic, health checks, and graceful shutdown. Full source code is on GitHub. What We’re Building A single-node consensus layer that: Produces blocks continuously Handles transient failures with exponential backoff Exposes health checks for orchestration Supports graceful shutdown Provides Prometheus metrics Application Structure The application has four main components:https://mikelle.github.io/blog/custom-geth-consensus/Sat, 07 Feb 2026 00:00:00 +0000https://mikelle.github.io/blog/custom-geth-consensus/Part 1 of the Custom Geth Consensus Series When Ethereum transitioned to Proof of Stake, Geth introduced the Engine API - a clean interface between execution and consensus layers. While designed for beacon chain integration, it also enables building custom consensus mechanisms. This series builds a complete custom consensus layer from scratch. We’ll start with fundamentals and progress to a production-ready distributed system. Full source code is on GitHub. Why Build Custom Consensus?