// successfully synced.
	SyncProxyRulesLastTimestamp = metrics.NewGauge(
		&metrics.GaugeOpts{
			Subsystem:      kubeProxySubsystem,
			Name:           "sync_proxy_rules_last_timestamp_seconds",
			Help:           "The last time proxy rules were successfully synced",
			StabilityLevel: metrics.ALPHA,
		},
	)