Respond when a data contract breaks

At a glance

Learning objectives

• Classify a breach by clause — schema, semantics, or SLA
• Bound the consumer impact set from lineage before assigning the fix
• Choose between a producer revert and a consumer adaptation

What you need

• The failing consumer's error and the producer's recent deploys
• Lineage for the broken asset
• The contract document with its SLA and breaking-change policy

Steps

1. Identify which contract clause broke — schema, semantics, or SLA. (from runbook-data-contract-broken )
2. Establish the impact set from lineage before anything else. (from runbook-data-contract-broken )
3. Determine if the fix is on the producer (revert) or consumer (adapt). (from runbook-data-contract-broken )
4. Schema breach → producer reverts or adds a compatibility shim. (from runbook-data-contract-broken )
5. SLA breach → negotiate a temporary relaxation and a root-cause fix. (from runbook-data-contract-broken )
6. Add consumer-driven contract tests in the producer's pipeline. (from runbook-data-contract-broken )

Check yourself

• The impact-set query returns every downstream consumer of the broken asset before anyone assigns the fix.
• A consumer that broke right after a producer deploy traces to a rename that changed semantics, and is treated as a breach.

Worked example

# impact set from lineage
SELECT * FROM lineage WHERE upstream = 'prod.orders' AND direction = 'downstream';

- Identify which contract clause broke (schema, semantics, or SLA).
- Establish the impact set from lineage before anything else.
- Determine if the fix is on the producer (revert) or consumer (adapt).

- Schema breach → producer reverts or adds a compatibility shim.
- SLA breach → negotiate a temporary relaxation and a root-cause fix.

Sourced from

• Data contract broken

Security scan

Last sweep 2026-10-24: 0 finding(s), 0 marked as examples.

Common gotchas

• A rename that changed semantics is still a breach, even when it looks safe.
• SLA misses can come from unrelated outages — root-cause before pointing at the producer.
• Whatever the fix, the consumer impact set comes first, from lineage.

Production considerations

• Contracts get CI enforcement and a dated deprecation path.
• Run consumer-driven contract tests in the producer's pipeline.

Diagram

contract broken
   |
   |- which clause broke? --> schema / semantics / SLA
   |
   |- impact set from lineage --> consumers listed first
   |
   |- schema breach --> producer reverts or adds a compatibility shim
   |
   |- SLA breach --> temporary relaxation --> root-cause fix

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