var getRemoteInstanceClient = func(r *http.Request, host string) (*miniogo.Core, error) {
	cred := getReqAccessCred(r, globalSite.Region)
	// In a federated deployment, all the instances share config files
	// and hence expected to have same credentials.
	core, err := miniogo.NewCore(host, &miniogo.Options{
		Creds:     credentials.NewStaticV4(cred.AccessKey, cred.SecretKey, ""),
		Secure:    globalIsTLS,

	mrfReplicaCh    chan ReplicationWorkerOperation
	mrfSaveCh       chan MRFReplicateEntry
	mrfStopCh       chan struct{}
	mrfWorkerSize   int
}

// ReplicationWorkerOperation is a shared interface of replication operations.
type ReplicationWorkerOperation interface {
	ToMRFEntry() MRFReplicateEntry
}

const (
	// WorkerMaxLimit max number of workers per node for "fast" mode