Address outstanding PR comments.

storage/metric/leveldb.go

@@ -188,7 +188,7 @@ func NewLevelDBMetricPersistence(baseDirectory string) (persistence *LevelDBMetr
 func (l *LevelDBMetricPersistence) AppendSample(sample model.Sample) (err error) {
 	begin := time.Now()
 	defer func() {
-		duration := time.Now().Sub(begin)
+		duration := time.Since(begin)
 
 		recordOutcome(duration, err, map[string]string{operation: appendSample, result: success}, map[string]string{operation: appendSample, result: failure})
 	}()
@@ -201,7 +201,7 @@ func (l *LevelDBMetricPersistence) AppendSample(sample model.Sample) (err error)
 func (l *LevelDBMetricPersistence) AppendSamples(samples model.Samples) (err error) {
 	begin := time.Now()
 	defer func() {
-		duration := time.Now().Sub(begin)
+		duration := time.Since(begin)
 
 		recordOutcome(duration, err, map[string]string{operation: appendSamples, result: success}, map[string]string{operation: appendSamples, result: failure})
 	}()
@@ -303,7 +303,6 @@ func (l *LevelDBMetricPersistence) AppendSamples(samples model.Samples) (err err
 		indexHas, err := l.hasIndexMetric(metricDTO)
 		if err != nil {
 			panic(err)
-			continue
 		}
 		if !indexHas {
 			absentFingerprints[fingerprint] = samples
@@ -570,7 +569,7 @@ func (l *LevelDBMetricPersistence) hasIndexMetric(dto *dto.Metric) (value bool,
 	begin := time.Now()
 
 	defer func() {
-		duration := time.Now().Sub(begin)
+		duration := time.Since(begin)
 
 		recordOutcome(duration, err, map[string]string{operation: hasIndexMetric, result: success}, map[string]string{operation: hasIndexMetric, result: failure})
 	}()
@@ -585,7 +584,7 @@ func (l *LevelDBMetricPersistence) HasLabelPair(dto *dto.LabelPair) (value bool,
 	begin := time.Now()
 
 	defer func() {
-		duration := time.Now().Sub(begin)
+		duration := time.Since(begin)
 
 		recordOutcome(duration, err, map[string]string{operation: hasLabelPair, result: success}, map[string]string{operation: hasLabelPair, result: failure})
 	}()
@@ -600,7 +599,7 @@ func (l *LevelDBMetricPersistence) HasLabelName(dto *dto.LabelName) (value bool,
 	begin := time.Now()
 
 	defer func() {
-		duration := time.Now().Sub(begin)
+		duration := time.Since(begin)
 
 		recordOutcome(duration, err, map[string]string{operation: hasLabelName, result: success}, map[string]string{operation: hasLabelName, result: failure})
 	}()
@@ -615,7 +614,7 @@ func (l *LevelDBMetricPersistence) GetFingerprintsForLabelSet(labelSet model.Lab
 	begin := time.Now()
 
 	defer func() {
-		duration := time.Now().Sub(begin)
+		duration := time.Since(begin)
 
 		recordOutcome(duration, err, map[string]string{operation: getFingerprintsForLabelSet, result: success}, map[string]string{operation: getFingerprintsForLabelSet, result: failure})
 	}()
@@ -665,7 +664,7 @@ func (l *LevelDBMetricPersistence) GetFingerprintsForLabelName(labelName model.L
 	begin := time.Now()
 
 	defer func() {
-		duration := time.Now().Sub(begin)
+		duration := time.Since(begin)
 
 		recordOutcome(duration, err, map[string]string{operation: getFingerprintsForLabelName, result: success}, map[string]string{operation: getFingerprintsForLabelName, result: failure})
 	}()
@@ -694,7 +693,7 @@ func (l *LevelDBMetricPersistence) GetMetricForFingerprint(f model.Fingerprint)
 	begin := time.Now()
 
 	defer func() {
-		duration := time.Now().Sub(begin)
+		duration := time.Since(begin)
 
 		recordOutcome(duration, err, map[string]string{operation: getMetricForFingerprint, result: success}, map[string]string{operation: getMetricForFingerprint, result: failure})
 	}()
@@ -727,7 +726,7 @@ func (l *LevelDBMetricPersistence) GetBoundaryValues(m model.Metric, i model.Int
 	begin := time.Now()
 
 	defer func() {
-		duration := time.Now().Sub(begin)
+		duration := time.Since(begin)
 
 		recordOutcome(duration, err, map[string]string{operation: getBoundaryValues, result: success}, map[string]string{operation: getBoundaryValues, result: failure})
 	}()
@@ -776,7 +775,7 @@ func (l *LevelDBMetricPersistence) GetValueAtTime(m model.Metric, t time.Time, s
 	begin := time.Now()
 
 	defer func() {
-		duration := time.Now().Sub(begin)
+		duration := time.Since(begin)
 
 		recordOutcome(duration, err, map[string]string{operation: getValueAtTime, result: success}, map[string]string{operation: getValueAtTime, result: failure})
 	}()
@@ -992,7 +991,7 @@ func (l *LevelDBMetricPersistence) GetRangeValues(m model.Metric, i model.Interv
 	begin := time.Now()
 
 	defer func() {
-		duration := time.Now().Sub(begin)
+		duration := time.Since(begin)
 
 		recordOutcome(duration, err, map[string]string{operation: getRangeValues, result: success}, map[string]string{operation: getRangeValues, result: failure})
 	}()

storage/metric/memory.go

@@ -69,11 +69,11 @@ func (s stream) forEach(decoder storage.RecordDecoder, filter storage.RecordFilt
 	for !(iterator.Key() == nil || iterator.Value() == nil) {
 		decodedKey, decodeErr := decoder.DecodeKey(iterator.Key())
 		if decodeErr != nil {
-			continue
+			panic(decodeErr)
 		}
 		decodedValue, decodeErr := decoder.DecodeValue(iterator.Value())
 		if decodeErr != nil {
-			continue
+			panic(decodeErr)
 		}
 
 		switch filter.Filter(decodedKey, decodedValue) {

storage/metric/tiered.go

@@ -60,6 +60,7 @@ type Storage interface {
 	// Stops the storage subsystem, flushing all pending operations.
 	Drain()
 	Flush()
+	Close()
 }
 
 func NewTieredStorage(appendToMemoryQueueDepth, appendToDiskQueueDepth, viewQueueDepth uint, flushMemoryInterval, writeMemoryInterval, memoryTTL time.Duration, root string) Storage {
@@ -126,7 +127,7 @@ func (t *tieredStorage) MakeView(builder ViewRequestBuilder, deadline time.Durat
 func (t *tieredStorage) rebuildDiskFrontier() (err error) {
 	begin := time.Now()
 	defer func() {
-		duration := time.Now().Sub(begin)
+		duration := time.Since(begin)
 
 		recordOutcome(duration, err, map[string]string{operation: appendSample, result: success}, map[string]string{operation: rebuildDiskFrontier, result: failure})
 	}()
@@ -181,7 +182,7 @@ func (t *tieredStorage) reportQueues() {
 func (t *tieredStorage) writeMemory() {
 	begin := time.Now()
 	defer func() {
-		duration := time.Now().Sub(begin)
+		duration := time.Since(begin)
 
 		recordOutcome(duration, nil, map[string]string{operation: appendSample, result: success}, map[string]string{operation: writeMemory, result: failure})
 	}()
@@ -200,9 +201,14 @@ func (t *tieredStorage) Flush() {
 	t.flush()
 }
 
+func (t *tieredStorage) Close() {
+	t.Drain()
+	t.diskStorage.Close()
+}
+
 // Write all pending appends.
 func (t *tieredStorage) flush() (err error) {
-	// Trim and old values to reduce iterative write costs.
+	// Trim any old values to reduce iterative write costs.
 	t.flushMemory()
 	t.writeMemory()
 	t.flushMemory()
@@ -299,7 +305,7 @@ func (f memoryToDiskFlusher) Close() {
 func (t *tieredStorage) flushMemory() {
 	begin := time.Now()
 	defer func() {
-		duration := time.Now().Sub(begin)
+		duration := time.Since(begin)
 
 		recordOutcome(duration, nil, map[string]string{operation: appendSample, result: success}, map[string]string{operation: flushMemory, result: failure})
 	}()
@@ -322,7 +328,7 @@ func (t *tieredStorage) flushMemory() {
 func (t *tieredStorage) renderView(viewJob viewJob) (err error) {
 	begin := time.Now()
 	defer func() {
-		duration := time.Now().Sub(begin)
+		duration := time.Since(begin)
 
 		recordOutcome(duration, err, map[string]string{operation: appendSample, result: success}, map[string]string{operation: renderView, result: failure})
 	}()