histogram: prometheus.NewHistogramVec(prometheus.HistogramOpts{
		Name:    "tier_ttlb_seconds",
		Help:    "Time taken by requests served by warm tier",
		Buckets: []float64{0.01, 0.1, 1, 2, 5, 10, 60, 5 * 60, 15 * 60, 30 * 60},
	}, []string{"tier"}),
}

func (t *tierMetrics) Observe(tier string, dur time.Duration) {
	t.histogram.With(prometheus.Labels{"tier": tier}).Observe(dur.Seconds())
}

	os.TransitionTier = info.Tier
	os.TransitionStatus = info.Status
	os.RemoteObject = info.Name
	os.TransitionVersionID = info.VersionID
}

// shouldRemoveRemoteObject determines if a transitioned object should be
// removed from remote tier. If remote object is to be deleted, returns the
// corresponding tier deletion journal entry and true. Otherwise returns empty
// jentry value and false.

			wg.Wait()

			// Reset for the next interval
			timer.Reset(globalAPIConfig.getDeleteCleanupInterval())
		}
	}
}

func (s *erasureSets) cleanupStaleUploads(ctx context.Context) {
	timer := time.NewTimer(globalAPIConfig.getStaleUploadsCleanupInterval())
	defer timer.Stop()

	for {
		select {
		case <-ctx.Done():
			return
		case <-timer.C:
			var wg sync.WaitGroup
			for _, set := range s.sets {

### Timer changes

Go 1.23 makes two significant changes to the implementation of
[time.Timer] and [time.Ticker].

First, `Timer`s and `Ticker`s that are no longer referred to by the program
become eligible for garbage collection immediately, even if their
`Stop` methods have not been called.
Earlier versions of Go did not collect unstopped `Timer`s until after
they had fired and never collected unstopped `Ticker`s.

	case madmin.Azure:
		d, err = newWarmBackendAzure(*tier.Azure, tier.Name)
	case madmin.GCS:
		d, err = newWarmBackendGCS(*tier.GCS, tier.Name)
	case madmin.MinIO:
		d, err = newWarmBackendMinIO(*tier.MinIO, tier.Name)
	default:
		return nil, errTierTypeUnsupported
	}
	if err != nil {
		return nil, errTierTypeUnsupported
	}

	if probe {
		if err = checkWarmBackend(ctx, d); err != nil {
			return nil, err

			return
		}

		op := auditTierOp{
			Tier:        tier,
			OutputBytes: bytes,
		}

		if err == nil {
			since := time.Since(startTime)
			op.TimeToResponseNS = since.Nanoseconds()
			globalTierMetrics.Observe(tier, since)
			globalTierMetrics.logSuccess(tier)
		} else {
			op.Error = err.Error()
			globalTierMetrics.logFailure(tier)
		}

}

func TestTransitionInfoEquals(t *testing.T) {
	inputs := []struct {
		tier            string
		remoteObjName   string
		remoteVersionID string
		status          string
	}{
		{
			tier:            "S3TIER-1",
			remoteObjName:   mustGetUUID(),
			remoteVersionID: mustGetUUID(),
			status:          "complete",
		},
		{
			tier:            "S3TIER-2",
			remoteObjName:   mustGetUUID(),

		Secure:    u.Scheme == "https",
		Transport: globalRemoteTargetTransport,
	}
	client, err := minio.New(u.Host, opts)
	if err != nil {
		return nil, err
	}
	client.SetAppInfo(fmt.Sprintf("s3-tier-%s", tier), ReleaseTag)

	core := &minio.Core{Client: client}
	return &warmBackendS3{
		client:       client,
		core:         core,
		Bucket:       conf.Bucket,

policy_count=$(./mc admin policy list myminio/ | wc -l)

## create a warm tier instance
(minio server /tmp/xltier/{1...4}/disk{0...1} --address :9002 2>&1 >/dev/null) &
sleep 30

export MC_HOST_mytier="http://minioadmin:minioadmin@localhost:9002/"

./mc mb -l myminio/bucket2
./mc mb -l mytier/tiered

## create a tier and set up ilm policy to tier immediately

	client, err := storage.NewClient(context.Background(),
		option.WithCredentialsJSON(credsJSON),
		option.WithScopes(storage.ScopeReadWrite),
		option.WithHTTPClient(clnt),
		option.WithUserAgent(fmt.Sprintf("gcs-tier-%s", tier)+SlashSeparator+ReleaseTag),
	)
	if err != nil {
		return nil, err
	}
	return &warmBackendGCS{client, conf.Bucket, conf.Prefix, conf.StorageClass}, nil
}