ISS-Based BFT #53 Milestone 4: Automatic Pruning & Operational Maturity

Milestone 4: Automatic Pruning & Operational Maturity

| Estimated Delivery | Month 5 (August 2026 if approved in March) | | :---- | :---- | | Focus | Automatic distributed pruning, operational tooling, documentation |

Deliverables:

• Automatic distributed trustful pruning: ordering nodes periodically exchange highest consecutively completed block and epoch information; eligible blocks are pruned automatically once all nodes acknowledge delivery.
• Pruning safety enforcement: unexpired batches are retained regardless of acknowledgment status; pruning operates at epoch granularity; partial metadata retention for deduplication of unexpired proofs.
• Updated operator manuals covering BFT domain bootstrap, sequencer onboarding, governance examples, trust model and assumptions, and pruning configuration.
• Metrics and logging for all BFT ordering modules: mempool depth, availability dissemination latency, consensus progress per segment, timestamp drift, and pruning status.
• Code complete: All code merged into the open-source Canton repository with appropriate unit and integration test coverage, including fault injection tests for Byzantine scenarios.

Acceptance Criteria:

• Demonstrable fault tolerance: Demonstrate that performance doesn't drop when an ordering node drops out of the quorum.

_Originally posted by @hythloda in https://github.com/canton-foundation/canton-dev-fund/issues/53#issuecomment-4254775393_