}

var (
	// compactorsMu guards access to compactors map
	compactorsMu sync.Mutex
	compactors   = map[string]*runningCompactor{}
	// dbMetricsMonitorsMu guards access to dbMetricsMonitors map
	dbMetricsMonitorsMu sync.Mutex
	dbMetricsMonitors   map[string]struct{}
)

// startCompactorOnce start one compactor per transport. If the interval get smaller on repeated calls, the