feat(filer): object size distribution metric and dashboard panels (#9902)

* feat(filer): record object size distribution histogram

Add SeaweedFS_filer_object_size_bytes, a histogram sampled when an
object is first created in the filer namespace, covering every write
protocol (S3, WebDAV, FUSE mount, direct HTTP). Buckets follow the
1KB/100KB/1MB/100MB/1GB ranges operators use to size collections.
Directories, overwrites, and metadata-only updates are not sampled, so
the bucket counts track the size distribution of distinct objects.

* feat(metrics): add filer object size distribution dashboard panels

Add a write-rate-by-size-range graph and a size-distribution bar gauge,
driven by SeaweedFS_filer_object_size_bytes, to the standalone and Helm
Grafana dashboards. Per-range subtractions are clamped at zero so
transient negative rate() samples do not render below the axis.

k8s/charts/seaweedfs/dashboards/seaweedfs-grafana-dashboard.json

@@ -3666,6 +3666,291 @@
       ],
       "title": "S3 Bucket Object Count",
       "type": "timeseries"
+    },
+    {
+      "collapsed": false,
+      "datasource": {
+        "type": "prometheus",
+        "uid": "${DS_PROMETHEUS}"
+      },
+      "gridPos": {
+        "h": 1,
+        "w": 24,
+        "x": 0,
+        "y": 130
+      },
+      "id": 92,
+      "panels": [],
+      "title": "Filer Object Size Distribution",
+      "type": "row"
+    },
+    {
+      "datasource": {
+        "type": "prometheus",
+        "uid": "${DS_PROMETHEUS}"
+      },
+      "description": "Rate of new objects created, split by size range.",
+      "fieldConfig": {
+        "defaults": {
+          "color": {
+            "mode": "palette-classic"
+          },
+          "custom": {
+            "axisBorderShow": false,
+            "axisCenteredZero": false,
+            "axisColorMode": "text",
+            "axisLabel": "objects/s",
+            "axisPlacement": "auto",
+            "barAlignment": 0,
+            "drawStyle": "line",
+            "fillOpacity": 25,
+            "gradientMode": "none",
+            "hideFrom": {
+              "legend": false,
+              "tooltip": false,
+              "viz": false
+            },
+            "insertNulls": false,
+            "lineInterpolation": "linear",
+            "lineWidth": 1,
+            "pointSize": 4,
+            "scaleDistribution": {
+              "type": "linear"
+            },
+            "showPoints": "auto",
+            "spanNulls": false,
+            "stacking": {
+              "group": "A",
+              "mode": "normal"
+            },
+            "thresholdsStyle": {
+              "mode": "off"
+            }
+          },
+          "mappings": [],
+          "thresholds": {
+            "mode": "absolute",
+            "steps": [
+              {
+                "color": "green",
+                "value": null
+              }
+            ]
+          },
+          "unit": "short",
+          "unitScale": true
+        },
+        "overrides": []
+      },
+      "gridPos": {
+        "h": 8,
+        "w": 12,
+        "x": 0,
+        "y": 131
+      },
+      "id": 93,
+      "links": [],
+      "options": {
+        "legend": {
+          "calcs": [],
+          "displayMode": "list",
+          "placement": "bottom",
+          "showLegend": true
+        },
+        "tooltip": {
+          "mode": "single",
+          "sort": "none"
+        }
+      },
+      "pluginVersion": "8.1.2",
+      "targets": [
+        {
+          "exemplar": true,
+          "expr": "sum(rate(SeaweedFS_filer_object_size_bytes_bucket{le=\"1024\",namespace=\"$NAMESPACE\"}[$__rate_interval]))",
+          "format": "time_series",
+          "hide": false,
+          "instant": false,
+          "interval": "",
+          "intervalFactor": 2,
+          "legendFormat": "< 1KB",
+          "refId": "A",
+          "step": 60
+        },
+        {
+          "exemplar": true,
+          "expr": "clamp_min(sum(rate(SeaweedFS_filer_object_size_bytes_bucket{le=\"102400\",namespace=\"$NAMESPACE\"}[$__rate_interval])) - sum(rate(SeaweedFS_filer_object_size_bytes_bucket{le=\"1024\",namespace=\"$NAMESPACE\"}[$__rate_interval])), 0)",
+          "format": "time_series",
+          "hide": false,
+          "instant": false,
+          "interval": "",
+          "intervalFactor": 2,
+          "legendFormat": "1KB - 100KB",
+          "refId": "B",
+          "step": 60
+        },
+        {
+          "exemplar": true,
+          "expr": "clamp_min(sum(rate(SeaweedFS_filer_object_size_bytes_bucket{le=\"1.048576e+06\",namespace=\"$NAMESPACE\"}[$__rate_interval])) - sum(rate(SeaweedFS_filer_object_size_bytes_bucket{le=\"102400\",namespace=\"$NAMESPACE\"}[$__rate_interval])), 0)",
+          "format": "time_series",
+          "hide": false,
+          "instant": false,
+          "interval": "",
+          "intervalFactor": 2,
+          "legendFormat": "100KB - 1MB",
+          "refId": "C",
+          "step": 60
+        },
+        {
+          "exemplar": true,
+          "expr": "clamp_min(sum(rate(SeaweedFS_filer_object_size_bytes_bucket{le=\"1.048576e+08\",namespace=\"$NAMESPACE\"}[$__rate_interval])) - sum(rate(SeaweedFS_filer_object_size_bytes_bucket{le=\"1.048576e+06\",namespace=\"$NAMESPACE\"}[$__rate_interval])), 0)",
+          "format": "time_series",
+          "hide": false,
+          "instant": false,
+          "interval": "",
+          "intervalFactor": 2,
+          "legendFormat": "1MB - 100MB",
+          "refId": "D",
+          "step": 60
+        },
+        {
+          "exemplar": true,
+          "expr": "clamp_min(sum(rate(SeaweedFS_filer_object_size_bytes_bucket{le=\"1.073741824e+09\",namespace=\"$NAMESPACE\"}[$__rate_interval])) - sum(rate(SeaweedFS_filer_object_size_bytes_bucket{le=\"1.048576e+08\",namespace=\"$NAMESPACE\"}[$__rate_interval])), 0)",
+          "format": "time_series",
+          "hide": false,
+          "instant": false,
+          "interval": "",
+          "intervalFactor": 2,
+          "legendFormat": "100MB - 1GB",
+          "refId": "E",
+          "step": 60
+        },
+        {
+          "exemplar": true,
+          "expr": "clamp_min(sum(rate(SeaweedFS_filer_object_size_bytes_count{namespace=\"$NAMESPACE\"}[$__rate_interval])) - sum(rate(SeaweedFS_filer_object_size_bytes_bucket{le=\"1.073741824e+09\",namespace=\"$NAMESPACE\"}[$__rate_interval])), 0)",
+          "format": "time_series",
+          "hide": false,
+          "instant": false,
+          "interval": "",
+          "intervalFactor": 2,
+          "legendFormat": "> 1GB",
+          "refId": "F",
+          "step": 60
+        }
+      ],
+      "title": "Filer Object Write Rate by Size Range",
+      "type": "timeseries"
+    },
+    {
+      "datasource": {
+        "type": "prometheus",
+        "uid": "${DS_PROMETHEUS}"
+      },
+      "description": "Objects created per size range over the selected time window.",
+      "fieldConfig": {
+        "defaults": {
+          "color": {
+            "mode": "thresholds"
+          },
+          "mappings": [],
+          "min": 0,
+          "thresholds": {
+            "mode": "absolute",
+            "steps": [
+              {
+                "color": "green",
+                "value": null
+              }
+            ]
+          },
+          "unit": "short"
+        },
+        "overrides": []
+      },
+      "gridPos": {
+        "h": 8,
+        "w": 12,
+        "x": 12,
+        "y": 131
+      },
+      "id": 94,
+      "options": {
+        "displayMode": "gradient",
+        "orientation": "horizontal",
+        "reduceOptions": {
+          "calcs": [
+            "lastNotNull"
+          ],
+          "fields": "",
+          "values": false
+        },
+        "showUnfilled": true,
+        "valueMode": "color"
+      },
+      "pluginVersion": "8.1.2",
+      "targets": [
+        {
+          "exemplar": true,
+          "expr": "sum(increase(SeaweedFS_filer_object_size_bytes_bucket{le=\"1024\",namespace=\"$NAMESPACE\"}[$__range]))",
+          "format": "time_series",
+          "instant": true,
+          "interval": "",
+          "intervalFactor": 2,
+          "legendFormat": "< 1KB",
+          "refId": "A"
+        },
+        {
+          "exemplar": true,
+          "expr": "clamp_min(sum(increase(SeaweedFS_filer_object_size_bytes_bucket{le=\"102400\",namespace=\"$NAMESPACE\"}[$__range])) - sum(increase(SeaweedFS_filer_object_size_bytes_bucket{le=\"1024\",namespace=\"$NAMESPACE\"}[$__range])), 0)",
+          "format": "time_series",
+          "instant": true,
+          "interval": "",
+          "intervalFactor": 2,
+          "legendFormat": "1KB - 100KB",
+          "refId": "B"
+        },
+        {
+          "exemplar": true,
+          "expr": "clamp_min(sum(increase(SeaweedFS_filer_object_size_bytes_bucket{le=\"1.048576e+06\",namespace=\"$NAMESPACE\"}[$__range])) - sum(increase(SeaweedFS_filer_object_size_bytes_bucket{le=\"102400\",namespace=\"$NAMESPACE\"}[$__range])), 0)",
+          "format": "time_series",
+          "instant": true,
+          "interval": "",
+          "intervalFactor": 2,
+          "legendFormat": "100KB - 1MB",
+          "refId": "C"
+        },
+        {
+          "exemplar": true,
+          "expr": "clamp_min(sum(increase(SeaweedFS_filer_object_size_bytes_bucket{le=\"1.048576e+08\",namespace=\"$NAMESPACE\"}[$__range])) - sum(increase(SeaweedFS_filer_object_size_bytes_bucket{le=\"1.048576e+06\",namespace=\"$NAMESPACE\"}[$__range])), 0)",
+          "format": "time_series",
+          "instant": true,
+          "interval": "",
+          "intervalFactor": 2,
+          "legendFormat": "1MB - 100MB",
+          "refId": "D"
+        },
+        {
+          "exemplar": true,
+          "expr": "clamp_min(sum(increase(SeaweedFS_filer_object_size_bytes_bucket{le=\"1.073741824e+09\",namespace=\"$NAMESPACE\"}[$__range])) - sum(increase(SeaweedFS_filer_object_size_bytes_bucket{le=\"1.048576e+08\",namespace=\"$NAMESPACE\"}[$__range])), 0)",
+          "format": "time_series",
+          "instant": true,
+          "interval": "",
+          "intervalFactor": 2,
+          "legendFormat": "100MB - 1GB",
+          "refId": "E"
+        },
+        {
+          "exemplar": true,
+          "expr": "clamp_min(sum(increase(SeaweedFS_filer_object_size_bytes_count{namespace=\"$NAMESPACE\"}[$__range])) - sum(increase(SeaweedFS_filer_object_size_bytes_bucket{le=\"1.073741824e+09\",namespace=\"$NAMESPACE\"}[$__range])), 0)",
+          "format": "time_series",
+          "instant": true,
+          "interval": "",
+          "intervalFactor": 2,
+          "legendFormat": "> 1GB",
+          "refId": "F"
+        }
+      ],
+      "title": "Filer Object Size Distribution",
+      "type": "bargauge"
     }
   ],
   "refresh": "",

other/metrics/grafana_seaweedfs.json

@@ -623,6 +623,237 @@
               "show": true
             }
           ]
+        },
+        {
+          "aliasColors": {},
+          "bars": false,
+          "dashLength": 10,
+          "dashes": false,
+          "datasource": "${DS_PROMETHEUS}",
+          "editable": true,
+          "error": false,
+          "fill": 5,
+          "fillGradient": 0,
+          "grid": {},
+          "gridPos": {
+            "h": 7,
+            "w": 12,
+            "x": 0,
+            "y": 31
+          },
+          "hiddenSeries": false,
+          "id": 91,
+          "legend": {
+            "alignAsTable": true,
+            "avg": true,
+            "current": true,
+            "hideEmpty": false,
+            "hideZero": false,
+            "max": true,
+            "min": false,
+            "rightSide": true,
+            "show": true,
+            "total": false,
+            "values": true
+          },
+          "lines": true,
+          "linewidth": 2,
+          "links": [],
+          "nullPointMode": "null as zero",
+          "options": {
+            "alertThreshold": true
+          },
+          "percentage": false,
+          "pluginVersion": "8.1.2",
+          "pointradius": 5,
+          "points": false,
+          "renderer": "flot",
+          "seriesOverrides": [],
+          "spaceLength": 10,
+          "stack": true,
+          "steppedLine": false,
+          "targets": [
+            {
+              "expr": "sum(rate(SeaweedFS_filer_object_size_bytes_bucket{le=\"1024\"}[1m]))",
+              "format": "time_series",
+              "intervalFactor": 2,
+              "legendFormat": "< 1KB",
+              "refId": "A"
+            },
+            {
+              "expr": "clamp_min(sum(rate(SeaweedFS_filer_object_size_bytes_bucket{le=\"102400\"}[1m])) - sum(rate(SeaweedFS_filer_object_size_bytes_bucket{le=\"1024\"}[1m])), 0)",
+              "format": "time_series",
+              "intervalFactor": 2,
+              "legendFormat": "1KB - 100KB",
+              "refId": "B"
+            },
+            {
+              "expr": "clamp_min(sum(rate(SeaweedFS_filer_object_size_bytes_bucket{le=\"1.048576e+06\"}[1m])) - sum(rate(SeaweedFS_filer_object_size_bytes_bucket{le=\"102400\"}[1m])), 0)",
+              "format": "time_series",
+              "intervalFactor": 2,
+              "legendFormat": "100KB - 1MB",
+              "refId": "C"
+            },
+            {
+              "expr": "clamp_min(sum(rate(SeaweedFS_filer_object_size_bytes_bucket{le=\"1.048576e+08\"}[1m])) - sum(rate(SeaweedFS_filer_object_size_bytes_bucket{le=\"1.048576e+06\"}[1m])), 0)",
+              "format": "time_series",
+              "intervalFactor": 2,
+              "legendFormat": "1MB - 100MB",
+              "refId": "D"
+            },
+            {
+              "expr": "clamp_min(sum(rate(SeaweedFS_filer_object_size_bytes_bucket{le=\"1.073741824e+09\"}[1m])) - sum(rate(SeaweedFS_filer_object_size_bytes_bucket{le=\"1.048576e+08\"}[1m])), 0)",
+              "format": "time_series",
+              "intervalFactor": 2,
+              "legendFormat": "100MB - 1GB",
+              "refId": "E"
+            },
+            {
+              "expr": "clamp_min(sum(rate(SeaweedFS_filer_object_size_bytes_count[1m])) - sum(rate(SeaweedFS_filer_object_size_bytes_bucket{le=\"1.073741824e+09\"}[1m])), 0)",
+              "format": "time_series",
+              "intervalFactor": 2,
+              "legendFormat": "> 1GB",
+              "refId": "F"
+            }
+          ],
+          "thresholds": [],
+          "timeFrom": null,
+          "timeRegions": [],
+          "timeShift": null,
+          "title": "Filer Object Write Rate by Size Range",
+          "tooltip": {
+            "msResolution": false,
+            "shared": true,
+            "sort": 0,
+            "value_type": "individual"
+          },
+          "type": "graph",
+          "xaxis": {
+            "buckets": null,
+            "mode": "time",
+            "name": null,
+            "show": true,
+            "values": []
+          },
+          "yaxes": [
+            {
+              "format": "short",
+              "label": "objects/s",
+              "logBase": 1,
+              "max": null,
+              "min": 0,
+              "show": true
+            },
+            {
+              "format": "short",
+              "label": null,
+              "logBase": 1,
+              "max": null,
+              "min": null,
+              "show": true
+            }
+          ],
+          "yaxis": {
+            "align": false,
+            "alignLevel": null
+          }
+        },
+        {
+          "datasource": "${DS_PROMETHEUS}",
+          "description": "Objects created per size range over the selected time window.",
+          "fieldConfig": {
+            "defaults": {
+              "color": {
+                "mode": "thresholds"
+              },
+              "mappings": [],
+              "min": 0,
+              "thresholds": {
+                "mode": "absolute",
+                "steps": [
+                  {
+                    "color": "green",
+                    "value": null
+                  }
+                ]
+              },
+              "unit": "short"
+            },
+            "overrides": []
+          },
+          "gridPos": {
+            "h": 7,
+            "w": 12,
+            "x": 12,
+            "y": 31
+          },
+          "id": 92,
+          "options": {
+            "displayMode": "gradient",
+            "orientation": "horizontal",
+            "reduceOptions": {
+              "calcs": [
+                "lastNotNull"
+              ],
+              "fields": "",
+              "values": false
+            },
+            "showUnfilled": true,
+            "valueMode": "color"
+          },
+          "pluginVersion": "8.1.2",
+          "targets": [
+            {
+              "expr": "sum(increase(SeaweedFS_filer_object_size_bytes_bucket{le=\"1024\"}[$__range]))",
+              "format": "time_series",
+              "intervalFactor": 2,
+              "legendFormat": "< 1KB",
+              "refId": "A",
+              "instant": true
+            },
+            {
+              "expr": "clamp_min(sum(increase(SeaweedFS_filer_object_size_bytes_bucket{le=\"102400\"}[$__range])) - sum(increase(SeaweedFS_filer_object_size_bytes_bucket{le=\"1024\"}[$__range])), 0)",
+              "format": "time_series",
+              "intervalFactor": 2,
+              "legendFormat": "1KB - 100KB",
+              "refId": "B",
+              "instant": true
+            },
+            {
+              "expr": "clamp_min(sum(increase(SeaweedFS_filer_object_size_bytes_bucket{le=\"1.048576e+06\"}[$__range])) - sum(increase(SeaweedFS_filer_object_size_bytes_bucket{le=\"102400\"}[$__range])), 0)",
+              "format": "time_series",
+              "intervalFactor": 2,
+              "legendFormat": "100KB - 1MB",
+              "refId": "C",
+              "instant": true
+            },
+            {
+              "expr": "clamp_min(sum(increase(SeaweedFS_filer_object_size_bytes_bucket{le=\"1.048576e+08\"}[$__range])) - sum(increase(SeaweedFS_filer_object_size_bytes_bucket{le=\"1.048576e+06\"}[$__range])), 0)",
+              "format": "time_series",
+              "intervalFactor": 2,
+              "legendFormat": "1MB - 100MB",
+              "refId": "D",
+              "instant": true
+            },
+            {
+              "expr": "clamp_min(sum(increase(SeaweedFS_filer_object_size_bytes_bucket{le=\"1.073741824e+09\"}[$__range])) - sum(increase(SeaweedFS_filer_object_size_bytes_bucket{le=\"1.048576e+08\"}[$__range])), 0)",
+              "format": "time_series",
+              "intervalFactor": 2,
+              "legendFormat": "100MB - 1GB",
+              "refId": "E",
+              "instant": true
+            },
+            {
+              "expr": "clamp_min(sum(increase(SeaweedFS_filer_object_size_bytes_count[$__range])) - sum(increase(SeaweedFS_filer_object_size_bytes_bucket{le=\"1.073741824e+09\"}[$__range])), 0)",
+              "format": "time_series",
+              "intervalFactor": 2,
+              "legendFormat": "> 1GB",
+              "refId": "F",
+              "instant": true
+            }
+          ],
+          "title": "Filer Object Size Distribution",
+          "type": "bargauge"
         }
       ],
       "repeat": null,

weed/filer/filer.go

@@ -22,6 +22,7 @@ import (
 
 	"github.com/seaweedfs/seaweedfs/weed/glog"
 	"github.com/seaweedfs/seaweedfs/weed/pb/filer_pb"
+	"github.com/seaweedfs/seaweedfs/weed/stats"
 	"github.com/seaweedfs/seaweedfs/weed/util"
 	"github.com/seaweedfs/seaweedfs/weed/util/log_buffer"
 	"github.com/seaweedfs/seaweedfs/weed/wdclient"
@@ -256,6 +257,9 @@ func (f *Filer) CreateEntry(ctx context.Context, entry *Entry, existing *Entry,
 			glog.ErrorfCtx(ctx, "insert entry %s: %v", entry.FullPath, err)
 			return fmt.Errorf("insert entry %s: %v", entry.FullPath, err)
 		}
+		if !entry.IsDirectory() {
+			stats.FilerObjectSizeBytesHistogram.Observe(float64(entry.Size()))
+		}
 	} else {
 		if o_excl {
 			glog.V(3).InfofCtx(ctx, "EEXIST: entry %s already exists", entry.FullPath)

weed/filer/leveldb/object_size_metric_test.go

@@ -0,0 +1,75 @@
+package leveldb
+
+import (
+	"context"
+	"os"
+	"testing"
+
+	dto "github.com/prometheus/client_model/go"
+
+	"github.com/seaweedfs/seaweedfs/weed/filer"
+	"github.com/seaweedfs/seaweedfs/weed/pb"
+	"github.com/seaweedfs/seaweedfs/weed/stats"
+	"github.com/seaweedfs/seaweedfs/weed/util"
+)
+
+func histogramState(t *testing.T) (count uint64, perBucket map[float64]uint64) {
+	t.Helper()
+	m := &dto.Metric{}
+	if err := stats.FilerObjectSizeBytesHistogram.Write(m); err != nil {
+		t.Fatalf("write histogram: %v", err)
+	}
+	perBucket = make(map[float64]uint64)
+	for _, b := range m.GetHistogram().GetBucket() {
+		perBucket[b.GetUpperBound()] = b.GetCumulativeCount()
+	}
+	return m.GetHistogram().GetSampleCount(), perBucket
+}
+
+func TestCreateEntryRecordsObjectSize(t *testing.T) {
+	testFiler := filer.NewFiler(pb.ServerDiscovery{}, nil, "", "", "", "", "", 255, nil)
+	store := &LevelDBStore{}
+	if err := store.initialize(t.TempDir()); err != nil {
+		t.Fatalf("init store: %v", err)
+	}
+	testFiler.SetStore(store)
+	defer testFiler.Shutdown()
+	ctx := context.Background()
+
+	file := func(path string, size uint64) *filer.Entry {
+		return &filer.Entry{
+			FullPath: util.FullPath(path),
+			Attr:     filer.Attr{Mode: 0640, FileSize: size},
+		}
+	}
+
+	before, _ := histogramState(t)
+
+	if err := testFiler.CreateEntry(ctx, file("/data/small.txt", 500), nil, false, false, nil, false, 255); err != nil {
+		t.Fatalf("create small: %v", err)
+	}
+	if err := testFiler.CreateEntry(ctx, file("/data/big.bin", 5*1024*1024), nil, false, false, nil, false, 255); err != nil {
+		t.Fatalf("create big: %v", err)
+	}
+	dir := &filer.Entry{FullPath: util.FullPath("/data/sub"), Attr: filer.Attr{Mode: os.ModeDir | 0755}}
+	if err := testFiler.CreateEntry(ctx, dir, nil, false, false, nil, false, 255); err != nil {
+		t.Fatalf("create dir: %v", err)
+	}
+	// overwrite is an update, not a new object
+	if err := testFiler.CreateEntry(ctx, file("/data/small.txt", 800), nil, false, false, nil, false, 255); err != nil {
+		t.Fatalf("overwrite small: %v", err)
+	}
+
+	after, buckets := histogramState(t)
+
+	// only the two new files are sampled, into their respective ranges
+	if got := after - before; got != 2 {
+		t.Fatalf("expected 2 sampled objects, got %d", got)
+	}
+	if buckets[1024] < 1 {
+		t.Errorf("expected the 500-byte object in the <=1024 bucket, buckets=%v", buckets)
+	}
+	if buckets[104857600]-buckets[1048576] < 1 {
+		t.Errorf("expected the 5MB object in the (1MB,100MB] range, buckets=%v", buckets)
+	}
+}

weed/stats/metrics.go

@@ -199,6 +199,16 @@ var (
 			Help:      "The last send timestamp of the filer subscription.",
 		}, []string{"sourceFiler", "clientName", "path"})
 
+	// Sampled only on first creation, so counts track distinct objects.
+	FilerObjectSizeBytesHistogram = prometheus.NewHistogram(
+		prometheus.HistogramOpts{
+			Namespace: Namespace,
+			Subsystem: "filer",
+			Name:      "object_size_bytes",
+			Help:      "Distribution of object sizes in bytes, sampled when an object is first created.",
+			Buckets:   []float64{1024, 102400, 1048576, 104857600, 1073741824},
+		})
+
 	FilerStoreCounter = prometheus.NewCounterVec(
 		prometheus.CounterOpts{
 			Namespace: Namespace,
@@ -751,6 +761,7 @@ func init() {
 	Gather.MustRegister(FilerStoreHistogram)
 	Gather.MustRegister(FilerSyncOffsetGauge)
 	Gather.MustRegister(FilerServerLastSendTsOfSubscribeGauge)
+	Gather.MustRegister(FilerObjectSizeBytesHistogram)
 	Gather.MustRegister(collectors.NewGoCollector())
 	Gather.MustRegister(collectors.NewProcessCollector(collectors.ProcessCollectorOpts{}))