Type:      counterMetric,
	}
}

func getMinioProcessIOReadBytesMD() MetricDescription {
	return MetricDescription{
		Namespace: nodeMetricNamespace,
		Subsystem: ioSubsystem,
		Name:      readBytes,
		Help:      "Total bytes read by the process from the underlying storage system, /proc/[pid]/io read_bytes",
		Type:      counterMetric,

| `io_read_bytes`               | `counter` | Total bytes read by the process from the underlying storage system, /proc/[pid]/io read_bytes                  | `server` |
| `io_wchar_bytes`              | `counter` | Total bytes written by the process to the underlying storage system including page cache, /proc/[pid]/io wchar | `server` |

| `minio_node_io_read_bytes`                 | Total bytes read by the process from the underlying storage system, /proc/[pid]/io read_bytes.                  |
| `minio_node_io_wchar_bytes`                | Total bytes written by the process to the underlying storage system including page cache, /proc/[pid]/io wchar. |

	var xlMeta xlMetaV2
	var legacyPreserved bool
	var legacyEntries []string
	if len(dstBuf) > 0 {
		if isXL2V1Format(dstBuf) {
			if err = xlMeta.Load(dstBuf); err != nil {
				// Data appears corrupt. Drop data.
				xlMeta = xlMetaV2{}
			}
		} else {
			// This code-path is to preserve the legacy data.
			xlMetaLegacy := &xlMetaV1Object{}
			json := jsoniter.ConfigCompatibleWithStandardLibrary

		// hence not included in the collector path.
		pathComponents = pathComponents[:bucketIdx]
	}

	innerHandler := h.handle(pathComponents, isListingRequest, buckets)

	// Add tracing to the prom. handler
	tracedHandler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		tc, ok := r.Context().Value(mcontext.ContextTraceKey).(*mcontext.TraceCtxt)
		if ok {
			tc.FuncName = "handler.MetricsV3"

		meta[xhttp.ContentType] = oi.ContentType
	}

	meta[xhttp.AmzObjectTagging] = oi.UserTags
	meta[xhttp.AmzTagDirective] = "REPLACE"

	if sc == "" {
		sc = oi.StorageClass
	}
	// drop non standard storage classes for tiering from replication
	if sc != "" && (sc == storageclass.RRS || sc == storageclass.STANDARD) {
		meta[xhttp.AmzStorageClass] = sc
	}

	meta[xhttp.MinIOSourceETag] = oi.ETag

	processIOReadBytesMD              = NewCounterMD(processIOReadBytes, "Total bytes read by the process from the underlying storage system, /proc/[pid]/io read_bytes")
	processIOWCharBytesMD             = NewCounterMD(processIOWCharBytes, "Total bytes written by the process to the underlying storage system including page cache, /proc/[pid]/io wchar")

		}
	case madmin.ProfilerThreads:
		prof.record("threadcreate", 0, "before")
		prof.stopFn = func() ([]byte, error) {
			var buf bytes.Buffer
			err := pprof.Lookup("threadcreate").WriteTo(&buf, 0)
			return buf.Bytes(), err
		}
	case madmin.ProfilerGoroutines:
		prof.ext = "txt"
		prof.record("goroutine", 1, "before")
		prof.record("goroutine", 2, "before,debug=2")
		prof.stopFn = func() ([]byte, error) {

		// Start profiling locally as well.
		prof, err := startProfiler(profiler)
		if err != nil {
			hostErrs = append(hostErrs, NotificationPeerErr{
				Host: *thisAddr,
				Err:  err,
			})
		} else {
			globalProfiler[profiler] = prof
			hostErrs = append(hostErrs, NotificationPeerErr{
				Host: *thisAddr,
			})
		}
	}

	// drive timeout by default is 2 minutes, we do not need to wait longer.
	return save(name, time.Minute)
}

// dataUsageCacheVer indicates the cache version.
// Bumping the cache version will drop data from previous versions
// and write new data with the new version.
const (
	dataUsageCacheVerCurrent = 8
	dataUsageCacheVerV7      = 7
	dataUsageCacheVerV6      = 6
	dataUsageCacheVerV5      = 5