set archived_envelopes_total on start based on DB count

Before the count was reset every time process was restarted.
Also add 'db' label to distinguish between waku and whisper DBs.

Signed-off-by: Jakub Sokołowski <jakub@status.im>

mailserver/cleaner_test.go

@@ -93,7 +93,10 @@ func setupTestServer(t *testing.T) *WhisperMailServer {
 	db, _ := leveldb.Open(storage.NewMemStorage(), nil)
 
 	s.ms = &mailServer{
-		db:      &LevelDB{ldb: db},
+		db: &LevelDB{
+			ldb:  db,
+			done: make(chan struct{}),
+		},
 		adapter: &whisperAdapter{},
 	}
 	s.minRequestPoW = powRequirement

mailserver/mailserver_db.go

@@ -6,6 +6,9 @@ import (
 	"github.com/status-im/status-go/eth-node/types"
 )
 
+// every this many seconds check real envelopes count
+const envelopeCountCheckInterval = 60
+
 // DB is an interface to abstract interactions with the db so that the mailserver
 // is agnostic to the underlying technology used
 type DB interface {

mailserver/mailserver_db_leveldb.go

@@ -18,7 +18,9 @@ import (
 
 type LevelDB struct {
 	// We can't embed as there are some state problems with go-routines
-	ldb *leveldb.DB
+	ldb  *leveldb.DB
+	name string
+	done chan struct{}
 }
 
 type LevelDBIterator struct {
@@ -68,7 +70,41 @@ func NewLevelDB(dataDir string) (*LevelDB, error) {
 		log.Info("database is corrupted trying to recover", "path", dataDir)
 		db, err = leveldb.RecoverFile(dataDir, nil)
 	}
-	return &LevelDB{ldb: db}, err
+
+	instance := LevelDB{
+		ldb:  db,
+		name: dataDir, // name is used for metrics labels
+		done: make(chan struct{}),
+	}
+
+	// initialize the metric value
+	instance.updateArchivedEnvelopesCount()
+	// checking count on every insert is inefficient
+	go func() {
+		for {
+			select {
+			case <-instance.done:
+				return
+			case <-time.After(time.Second * envelopeCountCheckInterval):
+				instance.updateArchivedEnvelopesCount()
+			}
+		}
+	}()
+	return &instance, err
+}
+
+// GetEnvelope get an envelope by its key
+func (db *LevelDB) GetEnvelope(key *DBKey) ([]byte, error) {
+	defer recoverLevelDBPanics("GetEnvelope")
+	return db.ldb.Get(key.Bytes(), nil)
+}
+
+func (db *LevelDB) updateArchivedEnvelopesCount() {
+	if count, err := db.envelopesCount(); err != nil {
+		log.Warn("db query for envelopes count failed", "err", err)
+	} else {
+		archivedEnvelopesGauge.WithLabelValues(db.name).Set(float64(count))
+	}
 }
 
 // Build iterator returns an iterator given a start/end and a cursor
@@ -83,13 +119,6 @@ func (db *LevelDB) BuildIterator(query CursorQuery) (Iterator, error) {
 	return &LevelDBIterator{i}, nil
 }
 
-// GetEnvelope get an envelope by its key
-func (db *LevelDB) GetEnvelope(key *DBKey) ([]byte, error) {
-	defer recoverLevelDBPanics("GetEnvelope")
-
-	return db.ldb.Get(key.Bytes(), nil)
-}
-
 // Prune removes envelopes older than time
 func (db *LevelDB) Prune(t time.Time, batchSize int) (int, error) {
 	defer recoverLevelDBPanics("Prune")
@@ -140,6 +169,20 @@ func (db *LevelDB) Prune(t time.Time, batchSize int) (int, error) {
 	return removed, nil
 }
 
+func (db *LevelDB) envelopesCount() (int, error) {
+	defer recoverLevelDBPanics("envelopesCount")
+	iterator, err := db.BuildIterator(CursorQuery{})
+	if err != nil {
+		return 0, err
+	}
+	// LevelDB does not have API for getting a count
+	var count int
+	for iterator.Next() {
+		count++
+	}
+	return count, nil
+}
+
 // SaveEnvelope stores an envelope in leveldb and increments the metrics
 func (db *LevelDB) SaveEnvelope(env types.Envelope) error {
 	defer recoverLevelDBPanics("SaveEnvelope")
@@ -148,20 +191,26 @@ func (db *LevelDB) SaveEnvelope(env types.Envelope) error {
 	rawEnvelope, err := rlp.EncodeToBytes(env.Unwrap())
 	if err != nil {
 		log.Error(fmt.Sprintf("rlp.EncodeToBytes failed: %s", err))
-		archivedErrorsCounter.Inc()
+		archivedErrorsCounter.WithLabelValues(db.name).Inc()
 		return err
 	}
 
 	if err = db.ldb.Put(key.Bytes(), rawEnvelope, nil); err != nil {
 		log.Error(fmt.Sprintf("Writing to DB failed: %s", err))
-		archivedErrorsCounter.Inc()
+		archivedErrorsCounter.WithLabelValues(db.name).Inc()
 	}
-	archivedEnvelopesCounter.Inc()
+	archivedEnvelopesGauge.WithLabelValues(db.name).Inc()
-	archivedEnvelopeSizeMeter.Observe(float64(whisper.EnvelopeHeaderLength + env.Size()))
+	archivedEnvelopeSizeMeter.WithLabelValues(db.name).Observe(
+		float64(whisper.EnvelopeHeaderLength + env.Size()))
 	return err
 }
 
 func (db *LevelDB) Close() error {
+	select {
+	case <-db.done:
+	default:
+		close(db.done)
+	}
 	return db.ldb.Close()
 }
 

mailserver/mailserver_db_postgres.go

@@ -24,7 +24,9 @@ import (
 )
 
 type PostgresDB struct {
-	db *sql.DB
+	db   *sql.DB
+	name string
+	done chan struct{}
 }
 
 func NewPostgresDB(uri string) (*PostgresDB, error) {
@@ -33,11 +35,32 @@ func NewPostgresDB(uri string) (*PostgresDB, error) {
 		return nil, err
 	}
 
-	instance := &PostgresDB{db: db}
+	instance := &PostgresDB{
+		db:   db,
+		done: make(chan struct{}),
+	}
 	if err := instance.setup(); err != nil {
 		return nil, err
 	}
 
+	// name is used for metrics labels
+	if name, err := instance.getDBName(uri); err == nil {
+		instance.name = name
+	}
+
+	// initialize the metric value
+	instance.updateArchivedEnvelopesCount()
+	// checking count on every insert is inefficient
+	go func() {
+		for {
+			select {
+			case <-instance.done:
+				return
+			case <-time.After(time.Second * envelopeCountCheckInterval):
+				instance.updateArchivedEnvelopesCount()
+			}
+		}
+	}()
 	return instance, nil
 }
 
@@ -45,6 +68,26 @@ type postgresIterator struct {
 	*sql.Rows
 }
 
+func (i *PostgresDB) getDBName(uri string) (string, error) {
+	query := "SELECT current_database()"
+	var dbName string
+	return dbName, i.db.QueryRow(query).Scan(&dbName)
+}
+
+func (i *PostgresDB) envelopesCount() (int, error) {
+	query := "SELECT count(*) FROM envelopes"
+	var count int
+	return count, i.db.QueryRow(query).Scan(&count)
+}
+
+func (i *PostgresDB) updateArchivedEnvelopesCount() {
+	if count, err := i.envelopesCount(); err != nil {
+		log.Warn("db query for envelopes count failed", "err", err)
+	} else {
+		archivedEnvelopesGauge.WithLabelValues(i.name).Set(float64(count))
+	}
+}
+
 func (i *postgresIterator) DBKey() (*DBKey, error) {
 	var value []byte
 	var id []byte
@@ -145,6 +188,11 @@ func (i *PostgresDB) setup() error {
 }
 
 func (i *PostgresDB) Close() error {
+	select {
+	case <-i.done:
+	default:
+		close(i.done)
+	}
 	return i.db.Close()
 }
 
@@ -196,11 +244,11 @@ func (i *PostgresDB) SaveEnvelope(env types.Envelope) error {
 	rawEnvelope, err := rlp.EncodeToBytes(env.Unwrap())
 	if err != nil {
 		log.Error(fmt.Sprintf("rlp.EncodeToBytes failed: %s", err))
-		archivedErrorsCounter.Inc()
+		archivedErrorsCounter.WithLabelValues(i.name).Inc()
 		return err
 	}
 	if rawEnvelope == nil {
-		archivedErrorsCounter.Inc()
+		archivedErrorsCounter.WithLabelValues(i.name).Inc()
 		return errors.New("failed to encode envelope to bytes")
 	}
 
@@ -220,12 +268,13 @@ func (i *PostgresDB) SaveEnvelope(env types.Envelope) error {
 	)
 
 	if err != nil {
-		archivedErrorsCounter.Inc()
+		archivedErrorsCounter.WithLabelValues(i.name).Inc()
 		return err
 	}
 
-	archivedEnvelopesCounter.Inc()
+	archivedEnvelopesGauge.WithLabelValues(i.name).Inc()
-	archivedEnvelopeSizeMeter.Observe(float64(whisper.EnvelopeHeaderLength + env.Size()))
+	archivedEnvelopeSizeMeter.WithLabelValues(i.name).Observe(
+		float64(whisper.EnvelopeHeaderLength + env.Size()))
 
 	return nil
 }

mailserver/metrics.go

@@ -43,23 +43,23 @@ var (
 		Help:    "Size of processed Whisper envelopes in bytes.",
 		Buckets: prom.ExponentialBuckets(1024, 4, 10),
 	})
-	archivedErrorsCounter = prom.NewCounter(prom.CounterOpts{
-		Name: "mailserver_archived_envelopes_falures_total",
-		Help: "Number of failures storing a Whisper envelope.",
-	})
-	archivedEnvelopesCounter = prom.NewCounter(prom.CounterOpts{
-		Name: "mailserver_archived_envelopes_total",
-		Help: "Number of envelopes saved.",
-	})
-	archivedEnvelopeSizeMeter = prom.NewHistogram(prom.HistogramOpts{
-		Name:    "mailserver_archived_envelope_size_bytes",
-		Help:    "Size of envelopes saved.",
-		Buckets: prom.ExponentialBuckets(1024, 2, 11),
-	})
 	mailDeliveryDuration = prom.NewHistogram(prom.HistogramOpts{
 		Name: "mailserver_delivery_duration_seconds",
 		Help: "Time it takes to deliver messages to a Whisper peer.",
 	})
+	archivedErrorsCounter = prom.NewCounterVec(prom.CounterOpts{
+		Name: "mailserver_archived_envelopes_falures_total",
+		Help: "Number of failures storing a Whisper envelope.",
+	}, []string{"db"})
+	archivedEnvelopesGauge = prom.NewGaugeVec(prom.GaugeOpts{
+		Name: "mailserver_archived_envelopes_total",
+		Help: "Number of envelopes saved in the DB.",
+	}, []string{"db"})
+	archivedEnvelopeSizeMeter = prom.NewHistogramVec(prom.HistogramOpts{
+		Name:    "mailserver_archived_envelope_size_bytes",
+		Help:    "Size of envelopes saved.",
+		Buckets: prom.ExponentialBuckets(1024, 2, 11),
+	}, []string{"db"})
 )
 
 func init() {
@@ -72,8 +72,8 @@ func init() {
 	prom.MustRegister(syncAttemptsCounter)
 	prom.MustRegister(sendRawEnvelopeDuration)
 	prom.MustRegister(sentEnvelopeBatchSizeMeter)
-	prom.MustRegister(archivedErrorsCounter)
-	prom.MustRegister(archivedEnvelopesCounter)
-	prom.MustRegister(archivedEnvelopeSizeMeter)
 	prom.MustRegister(mailDeliveryDuration)
+	prom.MustRegister(archivedErrorsCounter)
+	prom.MustRegister(archivedEnvelopesGauge)
+	prom.MustRegister(archivedEnvelopeSizeMeter)
 }