v1.0.0-beta.1: High-Availability Controller Leader Election (ADR-023)

Kuben v1.0.0-beta.1 — High-Availability Controller Leader Election (ADR-023)

Kuben v1.0.0-beta.1 advances high availability with the integration of ADR-023, establishing Kubernetes Lease-based Leader Election for multi-replica control plane deployments.

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High-Availability Architecture (ADR-023)

• Kubernetes Lease-Based Leader Election:
  • Coordinates controller execution across multiple replicas using standard coordination.k8s.io/Lease objects.
  • Active-passive controller failover: only the replica holding the Lease runs state reconciliation loops, eliminating split-brain race conditions.
• Continuous API & UI Availability:
  • Standby replicas continue serving API endpoints, web dashboards, and SSE telemetry without interruption.
  • Automatic Lease renewal and sub-second failover when a leader replica terminates gracefully or encounters a network partition.
• Observability & Diagnostics:
  • Health check endpoint (/healthz/details) surfaces subsystem operational status (leader, standby, or degraded).
  • Graceful release of the Lease during pod shutdown signals instant handover to waiting standby replicas.