After remote cache (23 Oct), this post covers schema registries: compatibility modes, subject naming, produce/consume validation, PII tags, CI gates, expand/contract evolution and register ACLs.

योजनाकोषधर्मः: A Metrical Codification of Schema Registries (with English glosses)

What this post is about

A schema registry is the system of record for event (and sometimes API) payload schemas and their compatibility rules.

Topics covered

1. Unversioned event breakage
2. BACKWARD/FORWARD/FULL modes
3. Subject naming
4. Producer validation
5. Consumer version bounds
6. PII field metadata
7. CI compatibility gates
8. Expand/contract field evolution
9. Who may register
10. Links to streams CDC versioning

Sanskrit title

योजनाकोषधर्मः = yojanā-koṣa-dharmaḥ “dharma of the schema treasury/registry”.

English

Minimizable; Sanskrit-first.

ग्राह्यम् / Keep

१. per-subject compat: explicit mode
२. stable subject names: no accidental forks
३. validate on produce: block poison
४. CI compat check: before merge
५. PII annotations: downstream filters
६. register ACL: not world-writable
७. optional-add first: remove after drain

त्याज्यम् / Avoid

• register any schema from any prod task role
• always use HARD break mode casually
• consumers on latest only with no test

पदच्छेदः
घटना रूपं यदि स्वैरं भिद्यते तदा ग्राहकाः नश्यन्ति । योजनाकोषधर्मस्तस्माद् रूपसत्यम् ॥१॥

Word-for-word

Gloss table

English sense
A schema registry stores and validates event/API payload schemas so producers and consumers share one evolving contract.

Context / topic
Topic: why schema registry. Pairs with CDC and streams.

वृत्तमिति: ८-८-८-८।

पदच्छेदः
compatibility BACKWARD FORWARD FULL । नीतिः विषयैः भिद्यताम् ॥२॥

Word-for-word

Gloss table

English sense
Pick compatibility mode per subject. Backward lets new consumers read old data; choose consciously.

Context / topic
Topic: compatibility modes. Links to API versioning spirit.

वृत्तमिति: ८-८-८-८।

पदच्छेदः
subject naming strategy stable । topic-record चौर्यं मा ॥३॥

Word-for-word

Gloss table

English sense
Stable subject names prevent accidental forks of the same stream into two schemas.

Context / topic
Topic: naming.

वृत्तमिति: ८-८-८-८।

पदच्छेदः
produce validate before send । poison schema pipeline हन्ति ॥४॥

Word-for-word

Gloss table

English sense
Producers should validate against the registry before publish. A bad schema poisons every consumer.

Context / topic
Topic: produce-time validation.

वृत्तमिति: ८-८-८-८।

पदच्छेदः
consume with specific version or compat range । latest blindly भङ्गाय ॥५॥

Word-for-word

Gloss table

English sense
Consumers should pin or bound schema versions they understand not silently take every latest breaking registration.

Context / topic
Topic: consume-time discipline.

वृत्तमिति: एकादशाक्षराः पादाः।

पदच्छेदः
PII fields in schema tagged । गोप्यता मार्गः स्पष्टः ॥६॥

Word-for-word

Gloss table

English sense
Mark sensitive fields in schema metadata so CDC filters and lakes can enforce privacy automatically.

Context / topic
Topic: privacy metadata. Links to CDC privacy.

वृत्तमिति: ८-८-८-८।

पदच्छेदः
CI gate: compat check on PR । runtime only fort late ॥७॥

Word-for-word

Gloss table

English sense
Run compatibility checks in CI quality gates before merge. Runtime registry denial is a last line not the first.

Context / topic
Topic: CI. Links to quality gates (22 Aug).

वृत्तमिति: ८-८-८-८।

पदच्छेदः
default values + optional fields expand । remove field only after sunsets ॥८॥

Word-for-word

Gloss table

English sense
Evolve like expand/contract migrations: add optional first, remove only after consumers drained.

Context / topic
Topic: evolution. Links to migrations + API versioning.

वृत्तमिति: ८-८-८-८।

पदच्छेदः
authz who can register subjects । open register विपत्तिः ॥९॥

Word-for-word

Gloss table

English sense
Lock who may upload schemas. An open registry is an open foot-gun on the bus.

Context / topic
Topic: registry authz.

वृत्तमिति: ८-८-८-८।

पदच्छेदः
घटनाप्रवाहः वाहनम् CDC जन्म । योजनाकोषः रूपं शास्ति ॥१०॥

Word-for-word

Gloss table

English sense
Streams carry bytes; CDC births change facts; the registry governs whether those bytes still mean what consumers think.

Context / topic
Topic: series triangle.

सन्धिः: प्रवाहः वहति; कोषः शासयति।

वृत्तमिति: एकादशाक्षराः पादाः।

पदच्छेदः
compat naming validate CI authz पञ्चकम् । एभिर्योजनाकोषो रूपसत्यसमन्वितः ॥११॥

Word-for-word

Gloss table

English sense
Five limbs: compatibility policy, stable subjects, produce/consume validation, CI gates and register ACLs.

Context / topic
Topic: checklist.

वृत्तमिति: ८-८-८-८।

पदच्छेदः
इति योजनाकोषधर्मसारो रूपसत्यसमन्वितः । मितं रूपं क्रियायोग्यं तन्त्रधर्मः स उच्यते ॥१२॥

Word-for-word

Gloss table

English sense
Closing: let payloads evolve in public with rules not in private with hope.

Context / topic
Topic: close.

उपसंहारन्यायः: रूपं कोषे बध्नाहि; सङ्गत्या वर्धय; CI पूर्वं वारय।

वृत्तमिति: ८-८-८-८।

१. Why registry
२. Compat modes
३. Naming
४. Produce validate
५. Consume pin
६. PII tags
७. CI gates
८. Evolve fields
९. Register ACL
१०. Stream/CDC link
११. Five limbs
१२. Close

1. Prior: streams 2026-07-30; CDC 2026-10-13; API versioning 2026-09-27; quality gates 2026-08-22.
2. Domain: event schema registries.
3. English minimizable; Sanskrit-first.
4. Style: no em dash; no Oxford comma in English clauses.