Code Review: First pass.

main.go

@@ -28,6 +28,7 @@ import (
 	"github.com/prometheus/prometheus/retrieval"
 	"github.com/prometheus/prometheus/rules"
 	"github.com/prometheus/prometheus/storage/metric"
+
 	"github.com/prometheus/prometheus/web"
 	"github.com/prometheus/prometheus/web/api"
 )
@@ -72,10 +73,9 @@ type prometheus struct {
 	bodyCompactionTimer *time.Ticker
 	tailCompactionTimer *time.Ticker
 	deletionTimer       *time.Ticker
-	reportDatabasesTimer     *time.Ticker
+
 	curationMutex            sync.Mutex
 	curationState            chan metric.CurationState
-	databaseStates           chan []string
 	stopBackgroundOperations chan bool
 
 	unwrittenSamples chan *extraction.Result
@@ -141,10 +141,6 @@ func (p *prometheus) close() {
 		p.deletionTimer.Stop()
 	}
 
-	if p.reportDatabasesTimer != nil {
-		p.reportDatabasesTimer.Stop()
-	}
-
 	if len(p.stopBackgroundOperations) == 0 {
 		p.stopBackgroundOperations <- true
 	}
@@ -157,26 +153,6 @@ func (p *prometheus) close() {
 	close(p.notifications)
 	close(p.stopBackgroundOperations)
 	close(p.curationState)
-	close(p.databaseStates)
-}
-
-func (p *prometheus) reportDatabaseState() {
-	for _ = range p.reportDatabasesTimer.C {
-		// BUG(matt): Per Julius, ...
-		// These channel magic tricks confuse me and seem a bit awkward just to
-		// pass a status around. Now that we have Go 1.1, would it be maybe be
-		// nicer to pass ts.DiskStorage.States as a method value
-		// (http://tip.golang.org/ref/spec#Method_values) to the web layer
-		// instead of doing this?
-		select {
-		case <-p.databaseStates:
-			// Reset the future database state if nobody consumes it.
-		case p.databaseStates <- p.storage.DiskStorage.States():
-			// Set the database state so someone can consume it if they want.
-		default:
-			// Don't block.
-		}
-	}
 }
 
 func main() {
@@ -206,7 +182,6 @@ func main() {
 
 	unwrittenSamples := make(chan *extraction.Result, *samplesQueueCapacity)
 	curationState := make(chan metric.CurationState, 1)
-	databaseStates := make(chan []string, 1)
 	// Coprime numbers, fool!
 	headCompactionTimer := time.NewTicker(*headCompactInterval)
 	bodyCompactionTimer := time.NewTicker(*bodyCompactInterval)
@@ -254,7 +229,7 @@ func main() {
 	}
 
 	databasesHandler := &web.DatabasesHandler{
-		Incoming: databaseStates,
+		Provider: ts.DiskStorage,
 	}
 
 	metricsService := &api.MetricsService{
@@ -277,10 +252,7 @@ func main() {
 
 		deletionTimer: deletionTimer,
 
-		reportDatabasesTimer: time.NewTicker(15 * time.Minute),
-
 		curationState: curationState,
-		databaseStates: databaseStates,
 
 		unwrittenSamples: unwrittenSamples,
 
@@ -297,7 +269,6 @@ func main() {
 	<-storageStarted
 
 	go prometheus.interruptHandler()
-	go prometheus.reportDatabaseState()
 
 	go func() {
 		for _ = range prometheus.headCompactionTimer.C {

storage/metric/index.go

@@ -14,6 +14,7 @@
 package metric
 
 import (
+	"io"
 	"sort"
 
 	"code.google.com/p/goprotobuf/proto"
@@ -30,14 +31,16 @@ import (
 type FingerprintMetricMapping map[clientmodel.Fingerprint]clientmodel.Metric
 
 type FingerprintMetricIndex interface {
+	io.Closer
+	raw.Pruner
+
 	IndexBatch(FingerprintMetricMapping) error
 	Lookup(*clientmodel.Fingerprint) (m clientmodel.Metric, ok bool, err error)
-	Close() error
+	State() *raw.DatabaseState
-	State() string
 	Size() (s uint64, present bool, err error)
 }
 
-type leveldbFingerprintMetricIndex struct {
+type LeveldbFingerprintMetricIndex struct {
 	p *leveldb.LevelDBPersistence
 }
 
@@ -45,22 +48,22 @@ type LevelDBFingerprintMetricIndexOptions struct {
 	leveldb.LevelDBOptions
 }
 
-func (i *leveldbFingerprintMetricIndex) Close() error {
+func (i *LeveldbFingerprintMetricIndex) Close() error {
 	i.p.Close()
 
 	return nil
 }
 
-func (i *leveldbFingerprintMetricIndex) State() string {
+func (i *LeveldbFingerprintMetricIndex) State() *raw.DatabaseState {
 	return i.p.State()
 }
 
-func (i *leveldbFingerprintMetricIndex) Size() (uint64, bool, error) {
+func (i *LeveldbFingerprintMetricIndex) Size() (uint64, bool, error) {
 	s, err := i.p.ApproximateSize()
 	return s, true, err
 }
 
-func (i *leveldbFingerprintMetricIndex) IndexBatch(mapping FingerprintMetricMapping) error {
+func (i *LeveldbFingerprintMetricIndex) IndexBatch(mapping FingerprintMetricMapping) error {
 	b := leveldb.NewBatch()
 	defer b.Close()
 
@@ -76,7 +79,7 @@ func (i *leveldbFingerprintMetricIndex) IndexBatch(mapping FingerprintMetricMapp
 	return i.p.Commit(b)
 }
 
-func (i *leveldbFingerprintMetricIndex) Lookup(f *clientmodel.Fingerprint) (m clientmodel.Metric, ok bool, err error) {
+func (i *LeveldbFingerprintMetricIndex) Lookup(f *clientmodel.Fingerprint) (m clientmodel.Metric, ok bool, err error) {
 	k := new(dto.Fingerprint)
 	dumpFingerprint(k, f)
 	v := new(dto.Metric)
@@ -95,13 +98,19 @@ func (i *leveldbFingerprintMetricIndex) Lookup(f *clientmodel.Fingerprint) (m cl
 	return m, true, nil
 }
 
+func (i *LeveldbFingerprintMetricIndex) Prune() (bool, error) {
+	i.p.Prune()
+
+	return false, nil
+}
+
 func NewLevelDBFingerprintMetricIndex(o *LevelDBFingerprintMetricIndexOptions) (FingerprintMetricIndex, error) {
 	s, err := leveldb.NewLevelDBPersistence(&o.LevelDBOptions)
 	if err != nil {
 		return nil, err
 	}
 
-	return &leveldbFingerprintMetricIndex{
+	return &LeveldbFingerprintMetricIndex{
 		p: s,
 	}, nil
 }
@@ -109,19 +118,21 @@ func NewLevelDBFingerprintMetricIndex(o *LevelDBFingerprintMetricIndexOptions) (
 type LabelNameFingerprintMapping map[clientmodel.LabelName]clientmodel.Fingerprints
 
 type LabelNameFingerprintIndex interface {
+	io.Closer
+	raw.Pruner
+
 	IndexBatch(LabelNameFingerprintMapping) error
 	Lookup(clientmodel.LabelName) (fps clientmodel.Fingerprints, ok bool, err error)
 	Has(clientmodel.LabelName) (ok bool, err error)
-	Close() error
+	State() *raw.DatabaseState
-	State() string
 	Size() (s uint64, present bool, err error)
 }
 
-type leveldbLabelNameFingerprintIndex struct {
+type LeveldbLabelNameFingerprintIndex struct {
 	p *leveldb.LevelDBPersistence
 }
 
-func (i *leveldbLabelNameFingerprintIndex) IndexBatch(b LabelNameFingerprintMapping) error {
+func (i *LeveldbLabelNameFingerprintIndex) IndexBatch(b LabelNameFingerprintMapping) error {
 	batch := leveldb.NewBatch()
 	defer batch.Close()
 
@@ -144,7 +155,7 @@ func (i *leveldbLabelNameFingerprintIndex) IndexBatch(b LabelNameFingerprintMapp
 	return i.p.Commit(batch)
 }
 
-func (i *leveldbLabelNameFingerprintIndex) Lookup(l clientmodel.LabelName) (fps clientmodel.Fingerprints, ok bool, err error) {
+func (i *LeveldbLabelNameFingerprintIndex) Lookup(l clientmodel.LabelName) (fps clientmodel.Fingerprints, ok bool, err error) {
 	k := new(dto.LabelName)
 	dumpLabelName(k, l)
 	v := new(dto.FingerprintCollection)
@@ -165,24 +176,30 @@ func (i *leveldbLabelNameFingerprintIndex) Lookup(l clientmodel.LabelName) (fps
 	return fps, true, nil
 }
 
-func (i *leveldbLabelNameFingerprintIndex) Has(l clientmodel.LabelName) (ok bool, err error) {
+func (i *LeveldbLabelNameFingerprintIndex) Has(l clientmodel.LabelName) (ok bool, err error) {
 	return i.p.Has(&dto.LabelName{
 		Name: proto.String(string(l)),
 	})
 }
 
-func (i *leveldbLabelNameFingerprintIndex) Close() error {
+func (i *LeveldbLabelNameFingerprintIndex) Prune() (bool, error) {
+	i.p.Prune()
+
+	return false, nil
+}
+
+func (i *LeveldbLabelNameFingerprintIndex) Close() error {
 	i.p.Close()
 
 	return nil
 }
 
-func (i *leveldbLabelNameFingerprintIndex) Size() (uint64, bool, error) {
+func (i *LeveldbLabelNameFingerprintIndex) Size() (uint64, bool, error) {
 	s, err := i.p.ApproximateSize()
 	return s, true, err
 }
 
-func (i *leveldbLabelNameFingerprintIndex) State() string {
+func (i *LeveldbLabelNameFingerprintIndex) State() *raw.DatabaseState {
 	return i.p.State()
 }
 
@@ -196,7 +213,7 @@ func NewLevelLabelNameFingerprintIndex(o *LevelDBLabelNameFingerprintIndexOption
 		return nil, err
 	}
 
-	return &leveldbLabelNameFingerprintIndex{
+	return &LeveldbLabelNameFingerprintIndex{
 		p: s,
 	}, nil
 }
@@ -204,17 +221,18 @@ func NewLevelLabelNameFingerprintIndex(o *LevelDBLabelNameFingerprintIndexOption
 type LabelSetFingerprintMapping map[LabelPair]clientmodel.Fingerprints
 
 type LabelSetFingerprintIndex interface {
+	io.Closer
 	raw.ForEacher
+	raw.Pruner
 
 	IndexBatch(LabelSetFingerprintMapping) error
 	Lookup(*LabelPair) (m clientmodel.Fingerprints, ok bool, err error)
 	Has(*LabelPair) (ok bool, err error)
-	Close() error
+	State() *raw.DatabaseState
-	State() string
 	Size() (s uint64, present bool, err error)
 }
 
-type leveldbLabelSetFingerprintIndex struct {
+type LeveldbLabelSetFingerprintIndex struct {
 	p *leveldb.LevelDBPersistence
 }
 
@@ -222,7 +240,7 @@ type LevelDBLabelSetFingerprintIndexOptions struct {
 	leveldb.LevelDBOptions
 }
 
-func (i *leveldbLabelSetFingerprintIndex) IndexBatch(m LabelSetFingerprintMapping) error {
+func (i *LeveldbLabelSetFingerprintIndex) IndexBatch(m LabelSetFingerprintMapping) error {
 	batch := leveldb.NewBatch()
 	defer batch.Close()
 
@@ -246,7 +264,7 @@ func (i *leveldbLabelSetFingerprintIndex) IndexBatch(m LabelSetFingerprintMappin
 	return i.p.Commit(batch)
 }
 
-func (i *leveldbLabelSetFingerprintIndex) Lookup(p *LabelPair) (m clientmodel.Fingerprints, ok bool, err error) {
+func (i *LeveldbLabelSetFingerprintIndex) Lookup(p *LabelPair) (m clientmodel.Fingerprints, ok bool, err error) {
 	k := &dto.LabelPair{
 		Name:  proto.String(string(p.Name)),
 		Value: proto.String(string(p.Value)),
@@ -271,7 +289,7 @@ func (i *leveldbLabelSetFingerprintIndex) Lookup(p *LabelPair) (m clientmodel.Fi
 	return m, true, nil
 }
 
-func (i *leveldbLabelSetFingerprintIndex) Has(p *LabelPair) (ok bool, err error) {
+func (i *LeveldbLabelSetFingerprintIndex) Has(p *LabelPair) (ok bool, err error) {
 	k := &dto.LabelPair{
 		Name:  proto.String(string(p.Name)),
 		Value: proto.String(string(p.Value)),
@@ -280,21 +298,27 @@ func (i *leveldbLabelSetFingerprintIndex) Has(p *LabelPair) (ok bool, err error)
 	return i.p.Has(k)
 }
 
-func (i *leveldbLabelSetFingerprintIndex) ForEach(d storage.RecordDecoder, f storage.RecordFilter, o storage.RecordOperator) (bool, error) {
+func (i *LeveldbLabelSetFingerprintIndex) ForEach(d storage.RecordDecoder, f storage.RecordFilter, o storage.RecordOperator) (bool, error) {
 	return i.p.ForEach(d, f, o)
 }
 
-func (i *leveldbLabelSetFingerprintIndex) Close() error {
+func (i *LeveldbLabelSetFingerprintIndex) Prune() (bool, error) {
+	i.p.Prune()
+	return false, nil
+}
+
+func (i *LeveldbLabelSetFingerprintIndex) Close() error {
 	i.p.Close()
+
 	return nil
 }
 
-func (i *leveldbLabelSetFingerprintIndex) Size() (uint64, bool, error) {
+func (i *LeveldbLabelSetFingerprintIndex) Size() (uint64, bool, error) {
 	s, err := i.p.ApproximateSize()
 	return s, true, err
 }
 
-func (i *leveldbLabelSetFingerprintIndex) State() string {
+func (i *LeveldbLabelSetFingerprintIndex) State() *raw.DatabaseState {
 	return i.p.State()
 }
 
@@ -304,26 +328,28 @@ func NewLevelDBLabelSetFingerprintIndex(o *LevelDBLabelSetFingerprintIndexOption
 		return nil, err
 	}
 
-	return &leveldbLabelSetFingerprintIndex{
+	return &LeveldbLabelSetFingerprintIndex{
 		p: s,
 	}, nil
 }
 
 type MetricMembershipIndex interface {
+	io.Closer
+	raw.Pruner
+
 	IndexBatch([]clientmodel.Metric) error
 	Has(clientmodel.Metric) (ok bool, err error)
-	Close() error
+	State() *raw.DatabaseState
-	State() string
 	Size() (s uint64, present bool, err error)
 }
 
-type leveldbMetricMembershipIndex struct {
+type LeveldbMetricMembershipIndex struct {
 	p *leveldb.LevelDBPersistence
 }
 
 var existenceIdentity = new(dto.MembershipIndexValue)
 
-func (i *leveldbMetricMembershipIndex) IndexBatch(ms []clientmodel.Metric) error {
+func (i *LeveldbMetricMembershipIndex) IndexBatch(ms []clientmodel.Metric) error {
 	batch := leveldb.NewBatch()
 	defer batch.Close()
 
@@ -336,28 +362,34 @@ func (i *leveldbMetricMembershipIndex) IndexBatch(ms []clientmodel.Metric) error
 	return i.p.Commit(batch)
 }
 
-func (i *leveldbMetricMembershipIndex) Has(m clientmodel.Metric) (ok bool, err error) {
+func (i *LeveldbMetricMembershipIndex) Has(m clientmodel.Metric) (ok bool, err error) {
 	k := new(dto.Metric)
 	dumpMetric(k, m)
 
 	return i.p.Has(k)
 }
 
-func (i *leveldbMetricMembershipIndex) Close() error {
+func (i *LeveldbMetricMembershipIndex) Close() error {
 	i.p.Close()
 
 	return nil
 }
 
-func (i *leveldbMetricMembershipIndex) Size() (uint64, bool, error) {
+func (i *LeveldbMetricMembershipIndex) Size() (uint64, bool, error) {
 	s, err := i.p.ApproximateSize()
 	return s, true, err
 }
 
-func (i *leveldbMetricMembershipIndex) State() string {
+func (i *LeveldbMetricMembershipIndex) State() *raw.DatabaseState {
 	return i.p.State()
 }
 
+func (i *LeveldbMetricMembershipIndex) Prune() (bool, error) {
+	i.p.Prune()
+
+	return false, nil
+}
+
 type LevelDBMetricMembershipIndexOptions struct {
 	leveldb.LevelDBOptions
 }
@@ -368,7 +400,7 @@ func NewLevelDBMetricMembershipIndex(o *LevelDBMetricMembershipIndexOptions) (Me
 		return nil, err
 	}
 
-	return &leveldbMetricMembershipIndex{
+	return &LeveldbMetricMembershipIndex{
 		p: s,
 	}, nil
 }

storage/metric/leveldb.go

@@ -28,6 +28,7 @@ import (
 	dto "github.com/prometheus/prometheus/model/generated"
 
 	"github.com/prometheus/prometheus/storage"
+	"github.com/prometheus/prometheus/storage/raw"
 	"github.com/prometheus/prometheus/storage/raw/leveldb"
 	"github.com/prometheus/prometheus/utility"
 )
@@ -88,7 +89,7 @@ func (l *LevelDBMetricPersistence) Close() {
 					closer.Close()
 				case errorCloser:
 					if err := closer.Close(); err != nil {
-						log.Println("anomaly closing", err)
+						log.Println("anomaly closing:", err)
 					}
 				}
 			}
@@ -767,14 +768,14 @@ func (l *LevelDBMetricPersistence) GetAllValuesForLabel(labelName clientmodel.La
 //
 // Beware that it would probably be imprudent to run this on a live user-facing
 // server due to latency implications.
-func (l *LevelDBMetricPersistence) CompactKeyspaces() {
+func (l *LevelDBMetricPersistence) Prune() {
-	l.CurationRemarks.CompactKeyspace()
+	l.CurationRemarks.Prune()
-	// l.fingerprintToMetrics.CompactKeyspace()
+	l.fingerprintToMetrics.Prune()
-	//	l.labelNameToFingerprints.CompactKeyspace()
+	l.labelNameToFingerprints.Prune()
-	//	l.labelSetToFingerprints.CompactKeyspace()
+	l.labelSetToFingerprints.Prune()
-	//	l.MetricHighWatermarks.CompactKeyspace()
+	l.MetricHighWatermarks.Prune()
-	// 	l.metricMembershipIndex.CompactKeyspace()
+	l.metricMembershipIndex.Prune()
-	l.MetricSamples.CompactKeyspace()
+	l.MetricSamples.Prune()
 }
 
 func (l *LevelDBMetricPersistence) ApproximateSizes() (total uint64, err error) {
@@ -818,8 +819,8 @@ func (l *LevelDBMetricPersistence) ApproximateSizes() (total uint64, err error)
 	return total, nil
 }
 
-func (l *LevelDBMetricPersistence) States() []string {
+func (l *LevelDBMetricPersistence) States() raw.DatabaseStates {
-	return []string{
+	return raw.DatabaseStates{
 		l.CurationRemarks.State(),
 		l.fingerprintToMetrics.State(),
 		l.labelNameToFingerprints.State(),

storage/metric/watermark.go

@@ -15,6 +15,7 @@ package metric
 
 import (
 	"container/list"
+	"io"
 	"sync"
 	"time"
 
@@ -170,20 +171,21 @@ func (lru *WatermarkCache) checkCapacity() {
 type FingerprintHighWatermarkMapping map[clientmodel.Fingerprint]time.Time
 
 type HighWatermarker interface {
+	io.Closer
 	raw.ForEacher
+	raw.Pruner
 
 	UpdateBatch(FingerprintHighWatermarkMapping) error
 	Get(*clientmodel.Fingerprint) (t time.Time, ok bool, err error)
-	Close() error
+	State() *raw.DatabaseState
-	State() string
 	Size() (uint64, bool, error)
 }
 
-type leveldbHighWatermarker struct {
+type LeveldbHighWatermarker struct {
 	p *leveldb.LevelDBPersistence
 }
 
-func (w *leveldbHighWatermarker) Get(f *clientmodel.Fingerprint) (t time.Time, ok bool, err error) {
+func (w *LeveldbHighWatermarker) Get(f *clientmodel.Fingerprint) (t time.Time, ok bool, err error) {
 	k := new(dto.Fingerprint)
 	dumpFingerprint(k, f)
 	v := new(dto.MetricHighWatermark)
@@ -198,7 +200,7 @@ func (w *leveldbHighWatermarker) Get(f *clientmodel.Fingerprint) (t time.Time, o
 	return t, true, nil
 }
 
-func (w *leveldbHighWatermarker) UpdateBatch(m FingerprintHighWatermarkMapping) error {
+func (w *LeveldbHighWatermarker) UpdateBatch(m FingerprintHighWatermarkMapping) error {
 	batch := leveldb.NewBatch()
 	defer batch.Close()
 
@@ -217,7 +219,7 @@ func (w *leveldbHighWatermarker) UpdateBatch(m FingerprintHighWatermarkMapping)
 			continue
 		}
 
-		// BUG(matt): Repace this with watermark management.
+		// BUG(matt): Replace this with watermark management.
 		if t.After(existing) {
 			v.Timestamp = proto.Int64(t.Unix())
 			batch.Put(k, v)
@@ -227,21 +229,27 @@ func (w *leveldbHighWatermarker) UpdateBatch(m FingerprintHighWatermarkMapping)
 	return w.p.Commit(batch)
 }
 
-func (i *leveldbHighWatermarker) ForEach(d storage.RecordDecoder, f storage.RecordFilter, o storage.RecordOperator) (bool, error) {
+func (i *LeveldbHighWatermarker) ForEach(d storage.RecordDecoder, f storage.RecordFilter, o storage.RecordOperator) (bool, error) {
 	return i.p.ForEach(d, f, o)
 }
 
-func (i *leveldbHighWatermarker) Close() error {
+func (i *LeveldbHighWatermarker) Prune() (bool, error) {
+	i.p.Prune()
+
+	return false, nil
+}
+
+func (i *LeveldbHighWatermarker) Close() error {
 	i.p.Close()
 
 	return nil
 }
 
-func (i *leveldbHighWatermarker) State() string {
+func (i *LeveldbHighWatermarker) State() *raw.DatabaseState {
 	return i.p.State()
 }
 
-func (i *leveldbHighWatermarker) Size() (uint64, bool, error) {
+func (i *LeveldbHighWatermarker) Size() (uint64, bool, error) {
 	s, err := i.p.ApproximateSize()
 	return s, true, err
 }
@@ -256,7 +264,7 @@ func NewLevelDBHighWatermarker(o *LevelDBHighWatermarkerOptions) (HighWatermarke
 		return nil, err
 	}
 
-	return &leveldbHighWatermarker{
+	return &LeveldbHighWatermarker{
 		p: s,
 	}, nil
 }

storage/raw/index/leveldb/leveldb.go

@@ -67,14 +67,14 @@ func (l *LevelDBMembershipIndex) Commit(batch raw.Batch) error {
 //
 // Beware that it would probably be imprudent to run this on a live user-facing
 // server due to latency implications.
-func (l *LevelDBMembershipIndex) CompactKeyspace() {
+func (l *LevelDBMembershipIndex) Prune() {
-	l.persistence.CompactKeyspace()
+	l.persistence.Prune()
 }
 
 func (l *LevelDBMembershipIndex) ApproximateSize() (uint64, error) {
 	return l.persistence.ApproximateSize()
 }
 
-func (l *LevelDBMembershipIndex) State() string {
+func (l *LevelDBMembershipIndex) State() *raw.DatabaseState {
 	return l.persistence.State()
 }

storage/raw/interface.go

@@ -64,3 +64,7 @@ type Batch interface {
 	// Drop follows the same protocol as Persistence.Drop.
 	Drop(key proto.Message)
 }
+
+type Pruner interface {
+	Prune() (noop bool, err error)
+}

storage/raw/leveldb/leveldb.go

@@ -163,6 +163,13 @@ func (i levigoIterator) GetError() (err error) {
 	return i.iterator.GetError()
 }
 
+type Compression uint
+
+const (
+	Snappy Compression = iota
+	Uncompressed
+)
+
 type LevelDBOptions struct {
 	Path    string
 	Name    string
@@ -174,15 +181,16 @@ type LevelDBOptions struct {
 	FlushOnMutate     bool
 	UseParanoidChecks bool
 
-	NotUseSnappy bool
+	Compression Compression
 }
 
 func NewLevelDBPersistence(o *LevelDBOptions) (*LevelDBPersistence, error) {
 	options := levigo.NewOptions()
 	options.SetCreateIfMissing(true)
 	options.SetParanoidChecks(o.UseParanoidChecks)
+
 	compression := levigo.SnappyCompression
-	if !o.NotUseSnappy {
+	if o.Compression == Uncompressed {
 		compression = levigo.NoCompression
 	}
 	options.SetCompression(compression)
@@ -313,7 +321,7 @@ func (l *LevelDBPersistence) Commit(b raw.Batch) (err error) {
 //
 // Beware that it would probably be imprudent to run this on a live user-facing
 // server due to latency implications.
-func (l *LevelDBPersistence) CompactKeyspace() {
+func (l *LevelDBPersistence) Prune() {
 
 	// Magic values per https://code.google.com/p/leveldb/source/browse/include/leveldb/db.h#131.
 	keyspace := levigo.Range{

storage/raw/leveldb/state.go

@@ -14,9 +14,7 @@
 package leveldb
 
 import (
-	"bytes"
+	"github.com/prometheus/prometheus/storage/raw"
-	"fmt"
-
 	"github.com/prometheus/prometheus/utility"
 )
 
@@ -25,50 +23,22 @@ const (
 	sstablesKey = "leveldb.sstables"
 )
 
-// DatabaseState models a bundle of metadata about a LevelDB database used in
+func (l *LevelDBPersistence) State() *raw.DatabaseState {
-// template format string interpolation.
+	databaseState := &raw.DatabaseState{
-type DatabaseState struct {
+		Location:     l.path,
-	Name            string
-	Purpose         string
-	Path            string
-	LowLevelStatus  string
-	SSTablesStatus  string
-	ApproximateSize utility.ByteSize
-	Error           error
-}
-
-func (s DatabaseState) String() string {
-	b := new(bytes.Buffer)
-
-	fmt.Fprintln(b, "Name:", s.Name)
-	fmt.Fprintln(b, "Path:", s.Path)
-	fmt.Fprintln(b, "Purpose:", s.Purpose)
-	fmt.Fprintln(b, "Low Level Diagnostics:", s.LowLevelStatus)
-	fmt.Fprintln(b, "SSTable Statistics:", s.SSTablesStatus)
-	fmt.Fprintln(b, "Approximate Size:", s.ApproximateSize)
-	fmt.Fprintln(b, "Error:", s.Error)
-
-	return b.String()
-}
-
-func (l *LevelDBPersistence) LowLevelState() DatabaseState {
-	databaseState := DatabaseState{
-		Path:           l.path,
 		Name:         l.name,
 		Purpose:      l.purpose,
-		LowLevelStatus: l.storage.PropertyValue(statsKey),
+		Supplemental: map[string]string{},
-		SSTablesStatus: l.storage.PropertyValue(sstablesKey),
 	}
 
 	if size, err := l.ApproximateSize(); err != nil {
-		databaseState.Error = err
+		databaseState.Supplemental["Errors"] = err.Error()
 	} else {
-		databaseState.ApproximateSize = utility.ByteSize(size)
+		databaseState.Size = utility.ByteSize(size)
 	}
 
+	databaseState.Supplemental["Low Level"] = l.storage.PropertyValue(statsKey)
+	databaseState.Supplemental["SSTable"] = l.storage.PropertyValue(sstablesKey)
+
 	return databaseState
 }
-
-func (l *LevelDBPersistence) State() string {
-	return l.LowLevelState().String()
-}

storage/raw/state.go

@@ -0,0 +1,53 @@
+// Copyright 2013 Prometheus Team
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package raw
+
+import (
+	"github.com/prometheus/prometheus/utility"
+)
+
+type DatabaseState struct {
+	Name string
+
+	Size utility.ByteSize
+
+	Location string
+	Purpose  string
+
+	Supplemental map[string]string
+}
+
+type DatabaseStates []*DatabaseState
+
+func (s DatabaseStates) Len() int {
+	return len(s)
+}
+
+func (s DatabaseStates) Less(i, j int) bool {
+	l := s[i]
+	r := s[j]
+
+	if l.Name > r.Name {
+		return false
+	}
+	if l.Name < r.Name {
+		return true
+	}
+
+	return l.Size < r.Size
+}
+
+func (s DatabaseStates) Swap(i, j int) {
+	s[i], s[j] = s[j], s[i]
+}

tools/pruner/main.go

@@ -44,7 +44,7 @@ func main() {
 	log.Printf("Starting compaction...")
 	size, _ := persistences.ApproximateSizes()
 	log.Printf("Original Size: %d", size)
-	persistences.CompactKeyspaces()
+	persistences.Prune()
 	log.Printf("Finished in %s", time.Since(start))
 	size, _ = persistences.ApproximateSizes()
 	log.Printf("New Size: %d", size)

web/databases.go

@@ -16,26 +16,45 @@ package web
 import (
 	"net/http"
 	"sync"
+	"time"
+
+	"github.com/prometheus/prometheus/storage/raw"
 )
 
-type DatabasesHandler struct {
+type DatabaseStatesProvider interface {
-	States []string
+	States() raw.DatabaseStates
+}
 
-	Incoming chan []string
+type DatabasesHandler struct {
+	RefreshInterval time.Duration
+	NextRefresh     time.Time
+
+	Current raw.DatabaseStates
+
+	Provider DatabaseStatesProvider
 
 	mutex sync.RWMutex
 }
 
 func (h *DatabasesHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
-	select {
+	h.Refresh()
-	case states := <-h.Incoming:
+
-		h.mutex.Lock()
-		defer h.mutex.Unlock()
-		h.States = states
-	default:
 	h.mutex.RLock()
 	defer h.mutex.RUnlock()
-	}
-
 	executeTemplate(w, "databases", h)
 }
+
+func (h *DatabasesHandler) Refresh() {
+	h.mutex.RLock()
+	if !time.Now().After(h.NextRefresh) {
+		h.mutex.RUnlock()
+		return
+	}
+	h.mutex.RUnlock()
+
+	h.mutex.Lock()
+	defer h.mutex.Unlock()
+
+	h.Current = h.Provider.States()
+	h.NextRefresh = time.Now().Add(h.RefreshInterval)
+}

web/templates/databases.html

@@ -3,34 +3,28 @@
 {{define "content"}}
     <div class="container-fluid">
       <h2>Database Information</h2>
-      {{range .States}}
+      {{range $database := .Current }}
-      <h3>{{.Name}}</h3>
+      <h3>{{$database.Name}}</h3>
       <table class="table table-bordered table-condensed table-hover literal_output">
         <tbody>
           <tr>
-            <th>Path</th>
+            <th>Location</th>
-            <td>{{.Path}}</td>
+            <td>{{$database.Location}}</td>
           </tr>
           <tr>
-            <th>Last Refreshed</th>
+            <th>Purpose</th>
-            <td>{{.LastRefreshed}}</td>
+            <td>{{$database.Purpose}}</td>
           </tr>
           <tr>
-            <th>Type</th>
+            <th>Size</th>
-            <td>{{.Type}}</td>
+            <td>{{$database.Size}}</td>
           </tr>
+          {{range $subject, $state := $database.Supplemental }}
           <tr>
-            <th>Approximate Size</th>
+            <th>{{$subject}}</th>
-            <td>{{.ApproximateSize}}</td>
+            <td><pre>{{$state}}</pre></td>
-          </tr>
-          <tr>
-            <th>Low Level Status</th>
-            <td><pre>{{.LowLevelStatus}}</pre></td>
-          </tr>
-          <tr>
-            <th>SSTable Status</th>
-            <td><pre>{{.SSTablesStatus}}</pre></td>
           </tr>
+          {{end}}
         </tbody>
       </table>
       {{end}}