Method cachedBackendHealth

internal/server/server.go:276–303

cachedBackendHealth probes adapter.Health per backend with TTL cache (shared by routing and /status).

(ctx context.Context)

// cachedBackendHealth probes adapter.Health per backend with TTL cache (shared by routing and /status).
func (s *Server) cachedBackendHealth(ctx context.Context) map[string]bool {
	ttl := time.Duration(s.cfg.Server.HealthCacheTTLMS) * time.Millisecond
	if ttl <= 0 {
		ttl = 2 * time.Second
	}
	perCheck := time.Duration(s.cfg.Server.HealthCheckPerMS) * time.Millisecond
	if perCheck <= 0 {
		perCheck = 1500 * time.Millisecond
	}

	if snap := s.peekFreshHealthSnapshot(ttl); snap != nil {
		return snap
	}

	v, _, _ := s.healthFlight.Do("backend_health", func() (interface{}, error) {
		if snap := s.peekFreshHealthSnapshot(ttl); snap != nil {
			return snap, nil
		}
		out := s.probeBackendHealth(perCheck)
		s.healthMu.Lock()
		s.healthSnapshot = out
		s.healthAt = time.Now()
		s.healthMu.Unlock()
		return out, nil
	})
	m, _ := v.(map[string]bool)
	return cloneBoolMap(m)
}

func (s *Server) peekFreshHealthSnapshot(ttl time.Duration) map[string]bool {
	s.healthMu.Lock()