Definition
Schema compatibility describes whether one schema version can read data written with another. Backward compatibility lets a new reader consume older data; forward compatibility lets an older reader consume newer data. Full compatibility covers both directions. Exact permitted changes depend on the serialization format and configured policy.
Why It Matters
- An order feed may serve fulfillment, analytics, and support systems that deploy at different times.
- A Commerce Intelligence OS needs readable event history as well as current events to connect decisions to their original evidence.
- A merchant integration owner needs to know which consumer must be upgraded before a producer changes its payload.
How It Works
- Inventory producers, consumers, event versions, and replay requirements. Choose whether checks cover the immediately previous schema or all retained versions.
- Test proposed changes against the real serialization format. Adding or removing a field is not universally compatible; defaults and required-field rules matter.
- Validate sample old and new payloads with actual consumers before deployment. Plan rollout order and retain a rollback path.
- Add a separate business-meaning review. A numeric field that changes from units to cases can remain structurally readable while changing the decision it supports.
Ecommerce Example
Context: Illustrative example: a retailer wants to add a warehouse reference to order events while one analytics consumer still uses the older schema.
Recommended move: The integration owner checks both reader directions and replays retained examples before approving the release. The chosen format determines whether a default or another migration step is required.
Why it matters: A separate owner verifies what the warehouse reference means for split orders. This is a proposed design example, not a claim about deployed iKawn infrastructure.
iKawn Framework
Describe
The iKawn ontology framework names event entities, fields, and business meanings.
Check
Test the schema versions used by each consuming workflow.
Release
Coordinate the sequence of producer and consumer changes.
Observe
Trace parsing failures and business mismatches after rollout.
Concise Summary
Schema compatibility protects event readability across versions. Commerce reliability also requires consumer tests and a separate check that field meanings remain correct.