type replicationResyncer struct {
	// map of bucket to their resync status
	statusMap      map[string]BucketReplicationResyncStatus
	workerSize     int
	resyncCancelCh chan struct{}
	workerCh       chan struct{}
	sync.RWMutex
}

const (
	replicationDir      = ".replication"
	resyncFileName      = "resync.bin"
	resyncMetaFormat    = 1
	resyncMetaVersionV1 = 1