# Total-Order Broadcast

> A mechanism that delivers every message to every node in the same order, agreed by consensus.

Record: `architecture:total-order-broadcast`
Kind: mechanism
Layer: [Causality Core](https://banes-lab.com/records/layer/causality-core.md)
Severity: contextual
Scope: event, distributed state, ordering
Canonical: https://banes-lab.com/ontology#architecture-total-order-broadcast

Listed in [Architecture principles](https://banes-lab.com/api/records/architecture.md), after [CRDTs](https://banes-lab.com/records/architecture/crdts.md) and before [CAP Theorem](https://banes-lab.com/records/architecture/cap-theorem.md).

## Repair

- Refactored by: Introduce Total-Order Broadcast
- Detected by: state divergence across nodes given same events
- Violated by: replicas applying events in divergent orders
- Measured by: cross-node order divergence rate
- Enforced by: distributed-systems review

## Requires

- [Consensus](https://banes-lab.com/records/architecture/consensus.md)

## Reinforces

- [Event Ordering](https://banes-lab.com/records/architecture/event-ordering.md)
- [Consistency](https://banes-lab.com/records/architecture/consistency.md)

## Enables

- [Identical Delivery Order Across Nodes](https://banes-lab.com/records/lexicon/identical-delivery-order-across-nodes.md)

## Conflicts with

- [Per-Node Independent Ordering](https://banes-lab.com/records/lexicon/per-node-independent-ordering.md)

## In tension with

- [Latency](https://banes-lab.com/records/architecture/latency.md)

## Tensions

- [Total-Order Broadcast / Latency](https://banes-lab.com/records/tension/latency-total-order-broadcast.md)

## Severity

- [contextual](https://banes-lab.com/records/vocabulary/severity-contextual.md)

## Category

- [Causality / Ordering / Distributed Time](https://banes-lab.com/records/architecture-category/causality-ordering-distributed-time.md)

## Linked from

- [Causality / Ordering / Distributed Time](https://banes-lab.com/ontology/principles/architecture-category-causality-ordering-distributed-time.md)
- [Control / Coordination / Centralization](https://banes-lab.com/ontology/principles/architecture-category-control-coordination-centralization.md)
- [Scalability / Performance / Optimization](https://banes-lab.com/ontology/principles/architecture-category-scalability-performance-optimization.md)
- [Transactions / State / Concurrency](https://banes-lab.com/ontology/principles/architecture-category-transactions-state-concurrency.md)
- [Causality / Ordering / Distributed Time](https://banes-lab.com/ontology/lexicon/lexicon-category-causality-ordering-distributed-time.md)
- [Severity levels](https://banes-lab.com/ontology/schema/the-vocabulary-severity.md)
- [The resolutions](https://banes-lab.com/ontology/schema/the-resolutions.md)