feat: Implement CHORUS scaling improvements for robust autoscaling
Address WHOOSH issue #7 with comprehensive scaling optimizations to prevent
license server, bootstrap peer, and control plane collapse during fast scale-out.
HIGH-RISK FIXES (Must-Do):
✅ License gate already implemented with cache + circuit breaker + grace window
✅ mDNS disabled in container environments (CHORUS_MDNS_ENABLED=false)
✅ Connection rate limiting (5 dials/sec, 16 concurrent DHT queries)
✅ Connection manager with watermarks (32 low, 128 high)
✅ AutoNAT enabled for container networking
MEDIUM-RISK FIXES (Next Priority):
✅ Assignment merge layer with HTTP/file config + SIGHUP reload
✅ Runtime configuration system with WHOOSH assignment API support
✅ Election stability windows to prevent churn:
- CHORUS_ELECTION_MIN_TERM=30s (minimum time between elections)
- CHORUS_LEADER_MIN_TERM=45s (minimum time before challenging healthy leader)
✅ Bootstrap pool JSON support with priority sorting and join stagger
NEW FEATURES:
- Runtime config system with assignment overrides from WHOOSH
- SIGHUP reload handler for live configuration updates
- JSON bootstrap configuration with peer metadata (region, roles, priority)
- Configurable election stability windows with environment variables
- Multi-format bootstrap support: Assignment → JSON → CSV
FILES MODIFIED:
- pkg/config/assignment.go (NEW): Runtime assignment merge system
- docker/bootstrap.json (NEW): Example JSON bootstrap configuration
- pkg/election/election.go: Added stability windows and churn prevention
- internal/runtime/shared.go: Integrated assignment loading and conditional mDNS
- p2p/node.go: Added connection management and rate limiting
- pkg/config/hybrid_config.go: Added rate limiting configuration fields
- docker/docker-compose.yml: Updated environment variables and configs
- README.md: Updated status table with scaling milestone
This implementation enables wave-based autoscaling without system collapse,
addressing all scaling concerns from WHOOSH issue #7.
🤖 Generated with [Claude Code](https://claude.ai/code)
Co-Authored-By: Claude <noreply@anthropic.com>
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