db: initialize more LevelMetrics fields on recovery

We weren't initializing all `LevelMetrics` fields when reading a
manifest. This isn't a big deal in practice because on the first
version change, we will reinitialize these fields.

This change reuses the code that normally sets these fields when
updating the version.

Author: RaduBerinde

metrics.go

@@ -978,19 +978,6 @@ func makeCompressionInfo(algorithm string, table, blob CompressionStatsForSettin
 // See testdata/metrics for an example.
 func (m *Metrics) String() string {
 	wb := ascii.Make(128 /* width */, 80 /* height */)
-	var total LevelMetrics
-	for l := range numLevels {
-		total.Add(&m.Levels[l])
-	}
-	// Compute total bytes-in as the bytes written to the WAL + bytes ingested.
-	total.TableBytesIn = m.WAL.BytesWritten + total.TableBytesIngested
-	// Add the total bytes-in to the total bytes-flushed. This is to account for
-	// the bytes written to the log and bytes written externally and then
-	// ingested.
-	total.TableBytesFlushed += total.TableBytesIn
-	total.Score = math.NaN()
-	total.FillFactor = math.NaN()
-	total.CompensatedFillFactor = math.NaN()
 
 	// LSM level metrics.
 	cur := wb.At(0, 0)
@@ -1165,6 +1152,18 @@ func (m *Metrics) String() string {
 	return wb.String()
 }
 
+func (m *Metrics) LevelMetricsString() string {
+	wb := ascii.Make(128 /* width */, 80 /* height */)
+
+	// LSM level metrics.
+	cur := wb.At(0, 0)
+	cur = cur.WriteString(levelMetricsTableTopHeader).NewlineReturn()
+	levelMetricsTable.Render(cur, table.RenderOptions{
+		HorizontalDividers: table.MakeHorizontalDividers(0, -1),
+	}, slices.Collect(m.LevelMetricsIter())...)
+	return wb.String()
+}
+
 func ifNonZero[T constraints.Integer](v T, s string) string {
 	if v > 0 {
 		return s

recovery.go

@@ -300,13 +300,7 @@ func recoverVersion(
 		MinimumAge:  opts.Experimental.ValueSeparationPolicy().RewriteMinimumAge,
 	})
 	vs.version = newVersion
-
-	for i := range vs.metrics.Levels {
-		l := &vs.metrics.Levels[i]
-		l.TablesCount = int64(newVersion.Levels[i].Len())
-		files := newVersion.Levels[i].Slice()
-		l.TablesSize = int64(files.TableSizeSum())
-	}
+	setBasicLevelMetrics(&vs.metrics, newVersion)
 	for _, l := range newVersion.Levels {
 		for f := range l.All() {
 			if !f.Virtual {

testdata/version_set

@@ -423,6 +423,16 @@ obsolete tables: 000102
 no zombie blob files
 no obsolete blob files
 
+metrics
+----
+LSM                             |    vtables   |   value sep   |        |   ingested   |    amp
+level       size | tables  size |  count  size |  refsz valblk |     in | tables  size |   r     w
+-----------------+--------------+--------------+---------------+--------+--------------+----------
+   L2       100B |      1  100B |      0     0 |     0B     0B |     0B |      0    0B |   1     0
+   L3       23KB |      3 2.9KB |      0     0 |   20KB     0B |     0B |      0    0B |   1     0
+-----------------+--------------+--------------+---------------+--------+--------------+----------
+total       23KB |      4   3KB |      0     0 |   20KB     0B |     0B |      0    0B |   2     0
+
 reopen
 ----
 current version:
@@ -440,6 +450,16 @@ no obsolete tables
 no zombie blob files
 no obsolete blob files
 
+metrics
+----
+LSM                             |    vtables   |   value sep   |        |   ingested   |    amp
+level       size | tables  size |  count  size |  refsz valblk |     in | tables  size |   r     w
+-----------------+--------------+--------------+---------------+--------+--------------+----------
+   L2       100B |      1  100B |      0     0 |     0B     0B |     0B |      0    0B |   1     0
+   L3       23KB |      3 2.9KB |      0     0 |   20KB     0B |     0B |      0    0B |   1     0
+-----------------+--------------+--------------+---------------+--------+--------------+----------
+total       23KB |      4   3KB |      0     0 |   20KB     0B |     0B |      0    0B |   2     0
+
 # Delete the referencing table and the blob file. There is no reference to the
 # previous Version, so the files should all be immediately obsolete.
 

tool/testdata/db_lsm

@@ -14,9 +14,9 @@ db lsm
 LSM                             |    vtables   |   value sep   |        |   ingested   |    amp
 level       size | tables  size |  count  size |  refsz valblk |     in | tables  size |   r     w
 -----------------+--------------+--------------+---------------+--------+--------------+----------
-   L0       709B |      1  709B |      0     0 |     0B     0B |     0B |      0    0B |   0     0
+   L0       709B |      1  709B |      0     0 |     0B     0B |     0B |      0    0B |   1     0
 -----------------+--------------+--------------+---------------+--------+--------------+----------
-total       709B |      1  709B |      0     0 |     0B     0B |     0B |      0    0B |   0     0
+total       709B |      1  709B |      0     0 |     0B     0B |     0B |      0    0B |   1     0
 
 COMPACTIONS               |     moved    |     multilevel    |     read     |       written
 level | score    ff   cff | tables  size |   top    in  read | tables  blob | tables  sstsz blobsz
@@ -80,9 +80,9 @@ db lsm --url
 LSM                             |    vtables   |   value sep   |        |   ingested   |    amp
 level       size | tables  size |  count  size |  refsz valblk |     in | tables  size |   r     w
 -----------------+--------------+--------------+---------------+--------+--------------+----------
-   L0       709B |      1  709B |      0     0 |     0B     0B |     0B |      0    0B |   0     0
+   L0       709B |      1  709B |      0     0 |     0B     0B |     0B |      0    0B |   1     0
 -----------------+--------------+--------------+---------------+--------+--------------+----------
-total       709B |      1  709B |      0     0 |     0B     0B |     0B |      0    0B |   0     0
+total       709B |      1  709B |      0     0 |     0B     0B |     0B |      0    0B |   1     0
 
 COMPACTIONS               |     moved    |     multilevel    |     read     |       written
 level | score    ff   cff | tables  size |   top    in  read | tables  blob | tables  sstsz blobsz

version_set.go

@@ -604,45 +604,7 @@ func (vs *versionSet) UpdateVersionLocked(
 	}
 
 	vs.metrics.updateLevelMetrics(vu.Metrics)
-	for i := range vs.metrics.Levels {
-		l := &vs.metrics.Levels[i]
-		l.TablesCount = int64(newVersion.Levels[i].Len())
-		l.VirtualTablesCount = newVersion.Levels[i].NumVirtual
-		l.VirtualTablesSize = newVersion.Levels[i].VirtualTableSize
-		l.TablesSize = int64(newVersion.Levels[i].TableSize())
-		l.EstimatedReferencesSize = newVersion.Levels[i].EstimatedReferenceSize()
-		l.Sublevels = 0
-		if l.TablesCount > 0 {
-			l.Sublevels = 1
-		}
-		if invariants.Enabled {
-			levelFiles := newVersion.Levels[i].Slice()
-			if size := int64(levelFiles.TableSizeSum()); l.TablesSize != size {
-				vs.opts.Logger.Fatalf("versionSet metrics L%d Size = %d, actual size = %d", i, l.TablesSize, size)
-			}
-			refSize := uint64(0)
-			for f := range levelFiles.All() {
-				refSize += f.EstimatedReferenceSize()
-			}
-			if refSize != l.EstimatedReferencesSize {
-				vs.opts.Logger.Fatalf("versionSet metrics L%d EstimatedReferencesSize = %d, recomputed size = %d", i, l.EstimatedReferencesSize, refSize)
-			}
-
-			if nVirtual := levelFiles.NumVirtual(); nVirtual != l.VirtualTablesCount {
-				vs.opts.Logger.Fatalf(
-					"versionSet metrics L%d NumVirtual = %d, actual NumVirtual = %d",
-					i, l.VirtualTablesCount, nVirtual,
-				)
-			}
-			if vSize := levelFiles.VirtualTableSizeSum(); vSize != l.VirtualTablesSize {
-				vs.opts.Logger.Fatalf(
-					"versionSet metrics L%d Virtual size = %d, actual size = %d",
-					i, l.VirtualTablesSize, vSize,
-				)
-			}
-		}
-	}
-	vs.metrics.Levels[0].Sublevels = int32(len(newVersion.L0SublevelFiles))
+	setBasicLevelMetrics(&vs.metrics, newVersion)
 	vs.metrics.Table.Local.LiveSize = uint64(int64(vs.metrics.Table.Local.LiveSize) + localTablesLiveDelta.size)
 	vs.metrics.Table.Local.LiveCount = uint64(int64(vs.metrics.Table.Local.LiveCount) + localTablesLiveDelta.count)
 	vs.metrics.BlobFiles.Local.LiveSize = uint64(int64(vs.metrics.BlobFiles.Local.LiveSize) + localBlobLiveDelta.size)
@@ -1111,6 +1073,55 @@ func (vs *versionSet) updateObsoleteObjectMetricsLocked() {
 	}
 }
 
+// This method sets the following fields of m.Levels[*]:
+//   - [Virtual]Tables{Count,Size}
+//   - Sublevels
+//   - EstimatedReferencesSize
+func setBasicLevelMetrics(m *Metrics, newVersion *manifest.Version) {
+	for i := range m.Levels {
+		l := &m.Levels[i]
+		l.TablesCount = int64(newVersion.Levels[i].Len())
+		l.TablesSize = int64(newVersion.Levels[i].TableSize())
+		l.VirtualTablesCount = newVersion.Levels[i].NumVirtual
+		l.VirtualTablesSize = newVersion.Levels[i].VirtualTableSize
+		l.EstimatedReferencesSize = newVersion.Levels[i].EstimatedReferenceSize()
+		l.Sublevels = 0
+		if l.TablesCount > 0 {
+			l.Sublevels = 1
+		}
+		if invariants.Enabled {
+			levelFiles := newVersion.Levels[i].Slice()
+			if size := int64(levelFiles.TableSizeSum()); l.TablesSize != size {
+				panic(fmt.Sprintf("versionSet metrics L%d Size = %d, actual size = %d", i, l.TablesSize, size))
+			}
+			refSize := uint64(0)
+			for f := range levelFiles.All() {
+				refSize += f.EstimatedReferenceSize()
+			}
+			if refSize != l.EstimatedReferencesSize {
+				panic(fmt.Sprintf(
+					"versionSet metrics L%d EstimatedReferencesSize = %d, recomputed size = %d",
+					i, l.EstimatedReferencesSize, refSize,
+				))
+			}
+
+			if nVirtual := levelFiles.NumVirtual(); nVirtual != l.VirtualTablesCount {
+				panic(fmt.Sprintf(
+					"versionSet metrics L%d NumVirtual = %d, actual NumVirtual = %d",
+					i, l.VirtualTablesCount, nVirtual,
+				))
+			}
+			if vSize := levelFiles.VirtualTableSizeSum(); vSize != l.VirtualTablesSize {
+				panic(fmt.Sprintf(
+					"versionSet metrics L%d Virtual size = %d, actual size = %d",
+					i, l.VirtualTablesSize, vSize,
+				))
+			}
+		}
+	}
+	m.Levels[0].Sublevels = int32(len(newVersion.L0SublevelFiles))
+}
+
 func findCurrentManifest(
 	fs vfs.FS, dirname string, ls []string,
 ) (marker *atomicfs.Marker, manifestNum base.DiskFileNum, exists bool, err error) {
@@ -1133,18 +1144,3 @@ func findCurrentManifest(
 	}
 	return marker, manifestNum, true, nil
 }
-
-func newFileMetrics(newFiles []manifest.NewTableEntry) levelMetricsDelta {
-	var m levelMetricsDelta
-	for _, nf := range newFiles {
-		lm := m[nf.Level]
-		if lm == nil {
-			lm = &LevelMetrics{}
-			m[nf.Level] = lm
-		}
-		lm.TablesCount++
-		lm.TablesSize += int64(nf.Meta.Size)
-		lm.EstimatedReferencesSize += nf.Meta.EstimatedReferenceSize()
-	}
-	return m
-}

version_set_test.go

@@ -232,6 +232,9 @@ func TestVersionSet(t *testing.T) {
 				}
 			}
 
+		case "metrics":
+			return vs.metrics.LevelMetricsString()
+
 		default:
 			td.Fatalf(t, "unknown command: %s", td.Cmd)
 		}
@@ -573,3 +576,18 @@ func TestCrashDuringManifestWrite_LargeKeys(t *testing.T) {
 		}()
 	}
 }
+
+func newFileMetrics(newFiles []manifest.NewTableEntry) levelMetricsDelta {
+	var m levelMetricsDelta
+	for _, nf := range newFiles {
+		lm := m[nf.Level]
+		if lm == nil {
+			lm = &LevelMetrics{}
+			m[nf.Level] = lm
+		}
+		lm.TablesCount++
+		lm.TablesSize += int64(nf.Meta.Size)
+		lm.EstimatedReferencesSize += nf.Meta.EstimatedReferenceSize()
+	}
+	return m
+}