Add metrics

compact_log.go

@@ -99,7 +99,7 @@ func compactLogIterate(filename string, f func(c *compaction)) error {
 		if err != nil {
 			return err
 		}
-		if _, err := fd.Read(buf[:1]); err != nil {
+		if _, err = fd.Read(buf[:1]); err != nil {
 			return err
 		}
 		c.done = buf[0]

kv.go

@@ -454,8 +454,10 @@ func (s *KV) get(key []byte) (y.ValueStruct, error) {
 	tables, decr := s.getMemTables() // Lock should be released.
 	defer decr()
 
+	y.NumGets.Add(1)
 	for i := 0; i < len(tables); i++ {
 		vs := tables[i].Get(key)
+		y.NumMemtableGets.Add(1)
 		if vs.Meta != 0 || vs.Value != nil {
 			return vs, nil
 		}
@@ -698,6 +700,7 @@ func (s *KV) sendToWriteCh(entries []*Entry) []*request {
 		b.Entries = append(b.Entries, entry)
 		if size >= s.opt.maxBatchSize {
 			s.writeCh <- b
+			y.NumPuts.Add(int64(len(b.Entries)))
 			reqs = append(reqs, b)
 			size = 0
 			b = nil
@@ -706,6 +709,7 @@ func (s *KV) sendToWriteCh(entries []*Entry) []*request {
 
 	if size > 0 {
 		s.writeCh <- b
+		y.NumPuts.Add(int64(len(b.Entries)))
 		reqs = append(reqs, b)
 	}
 	return reqs

level_handler.go

@@ -18,6 +18,7 @@ package badger
 
 import (
 	"bytes"
+	"fmt"
 	"sort"
 
 	"github.com/dgraph-io/badger/table"
@@ -37,6 +38,7 @@ type levelHandler struct {
 
 	// The following are initialized once and const.
 	level        int
+	strLevel     string
 	maxTotalSize int64
 	kv           *KV
 }
@@ -138,8 +140,9 @@ func (s *levelHandler) replaceTables(newTables []*table.Table) {
 
 func newLevelHandler(kv *KV, level int) *levelHandler {
 	return &levelHandler{
-		level: level,
-		kv:    kv,
+		level:    level,
+		strLevel: fmt.Sprintf("l%d", level),
+		kv:       kv,
 	}
 }
 
@@ -219,12 +222,14 @@ func (s *levelHandler) get(key []byte) (y.ValueStruct, error) {
 
 	for _, th := range tables {
 		if th.DoesNotHave(key) {
+			y.NumLSMBloomHits.Add(s.strLevel, 1)
 			continue
 		}
 
 		it := th.NewIterator(false)
 		defer it.Close()
 
+		y.NumLSMGets.Add(s.strLevel, 1)
 		it.Seek(key)
 		if !it.Valid() {
 			continue

levels.go

@@ -294,8 +294,7 @@ func (s *levelsController) compactBuildTables(
 			// Encode the level number as table metadata.
 			var levelNum [2]byte
 			binary.BigEndian.PutUint16(levelNum[:], uint16(l+1))
-			_, err = fd.Write(builder.Finish(levelNum[:]))
-			if err != nil {
+			if _, err := fd.Write(builder.Finish(levelNum[:])); err != nil {
 				che <- errors.Wrapf(err, "Unable to write to file: %d", fileID)
 				return
 			}

table/table.go

@@ -213,7 +213,9 @@ func (t *Table) read(off int, sz int) ([]byte, error) {
 	}
 
 	res := make([]byte, sz)
-	_, err := t.fd.ReadAt(res, int64(off))
+	nbr, err := t.fd.ReadAt(res, int64(off))
+	y.NumReads.Add(1)
+	y.NumBytesRead.Add(int64(nbr))
 	return res, err
 }
 
@@ -363,5 +365,7 @@ func (t *Table) LoadToRAM() error {
 	if err != nil || read != t.tableSize {
 		return y.Wrapf(err, "Unable to load file in memory. Table file: %s", t.Filename())
 	}
+	y.NumReads.Add(1)
+	y.NumBytesRead.Add(int64(read))
 	return nil
 }

value.go

@@ -81,7 +81,9 @@ func (lf *logFile) read(buf []byte, offset int64) error {
 	lf.RLock()
 	defer lf.RUnlock()
 
-	_, err := lf.fd.ReadAt(buf, offset)
+	nbr, err := lf.fd.ReadAt(buf, offset)
+	y.NumReads.Add(1)
+	y.NumBytesRead.Add(int64(nbr))
 	return err
 }
 
@@ -619,6 +621,8 @@ func (l *valueLog) write(reqs []*request) error {
 		if err != nil {
 			return errors.Wrapf(err, "Unable to write to value log file: %q", curlf.path)
 		}
+		y.NumWrites.Add(1)
+		y.NumBytesWritten.Add(int64(n))
 		l.elog.Printf("Done")
 		curlf.offset += uint32(n)
 		l.buf.Reset()

y/metrics.go

@@ -0,0 +1,46 @@
+/*
+ * Copyright (C) 2017 Dgraph Labs, Inc. and Contributors
+ *
+ * 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 y
+
+import (
+	"expvar"
+)
+
+var (
+	// These are cumulative
+	NumGets         *expvar.Int
+	NumPuts         *expvar.Int
+	NumReads        *expvar.Int
+	NumWrites       *expvar.Int
+	NumBytesRead    *expvar.Int
+	NumBytesWritten *expvar.Int
+	NumMemtableGets *expvar.Int
+	NumLSMGets      *expvar.Map
+	NumLSMBloomHits *expvar.Map
+)
+
+func init() {
+	NumReads = expvar.NewInt("badger_disk_reads_total")
+	NumWrites = expvar.NewInt("badger_disk_writes_total")
+	NumBytesRead = expvar.NewInt("badger_read_bytes")
+	NumBytesWritten = expvar.NewInt("badger_written_bytes")
+	NumGets = expvar.NewInt("badger_gets_total")
+	NumPuts = expvar.NewInt("badger_puts_total")
+	NumMemtableGets = expvar.NewInt("badger_memtable_gets_total")
+	NumLSMGets = expvar.NewMap("badger_lsm_level_gets_total")
+	NumLSMBloomHits = expvar.NewMap("badger_lsm_bloom_hits_total")
+}