Module cdc Future

CDC Module - Future Enhancements

Scope

• hardening and refinement of CDC capture/delivery/replay runtime paths
• expansion of deterministic reliability for transport, DLQ, and outbox behavior
• stricter benchmark-backed guardrails for CDC hot paths

Design Constraints

• CDC contracts remain backward compatible within major release line.
• capture/replay behavior remains deterministic under supported configurations.
• transport degradation paths remain bounded and observable.
• delivery semantics remain auditable through explicit state transitions.

Required Interfaces

Interface	Requirement
capture/replay interfaces	stable event record/replay semantics
delivery interfaces	explicit ack/redelivery and timeout behavior
transport interfaces	clear capability and failure classification
admin/ops interfaces	reliable control and diagnostics visibility

Implementation Notes

• tighten consistency of consumer-group and delivery-tracker failure semantics.
• standardize diagnostics across lag, replay, and redelivery classes.
• expand transport degradation resilience and failover behavior.
• continue replacing proxy-like mappings with dedicated CDC benchmarks.

Short-term Delivery Plan (Q3-Q4 2026)

• transport/replay hardening:
  • define deterministic degradation matrix for partial transport outages, reconnect churn, and backend timeout combinations.
  • enforce ordered replay + idempotent ack behavior across failover transitions.
• regression expansion:
  • expand focused replay/ack/timeout permutations with explicit DLQ/outbox transition assertions.
  • cover malformed-event and stale-offset paths with fail-closed classification checks.
• operator diagnostics:
  • normalize lag/redelivery/stream-integrity diagnostics into actionable, class-stable outputs.
  • require stream-id and consumer-group context in failure telemetry assertions.

Mid-term Delivery Plan (Q1 2027)

• benchmark re-baselining:
  • establish CDC-specific release baselines for p95/p99 latency and throughput under release profiles.
  • require stable multi-run variance before baseline promotion.
• dedicated microbench coverage:
  • replace proxy-like mappings with direct microbenchmarks for capture/list/replay/delivery hot paths.
  • close benchmark-manifest missing-case gaps for CDC critical functions.
• sustained consistency hardening:
  • validate multi-tenant and multi-transport determinism under long-running mixed workload and degraded-network conditions.
  • enforce bounded backlog/memory behavior with reproducible replay outcomes.

Test Strategy

• unit and integration suites across capture, replay, delivery, and admin flows.
• regression scenarios for DLQ/outbox, timeout, and redelivery behavior.
• degraded transport/backend deterministic fault-path tests.
• release-profile benchmark runs for mapped CDC targets.

Performance Targets

• event record/list/replay hot paths remain within release regression budgets.
• replication lag and WAN lag benchmark paths remain stable at p95/p99.
• benchmark manifests for mapped CDC targets reach no-missing-case status.
• baseline updates require documented variance stability across repeated release-profile runs.

Security / Reliability

• maintain strict delivery-state and replay contract integrity.
• preserve auditable CDC admin and failure decision paths.
• enforce bounded resource behavior in buffering and transport surfaces.
• keep diagnostics actionable for production CDC incidents.

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