remove badger version in the metrics name (#1982)

This PR also fixes the go lint issues caused by the previous commit.

db.go

@@ -899,7 +899,7 @@ func (db *DB) sendToWriteCh(entries []*Entry) (*request, error) {
 		size += e.estimateSizeAndSetThreshold(db.valueThreshold())
 		count++
 	}
-	y.NumBytesWrittenUserAdd(db.opt.MetricsEnabled, int64(size))
+	y.NumBytesWrittenUserAdd(db.opt.MetricsEnabled, size)
 	if count >= db.opt.maxBatchCount || size >= db.opt.maxBatchSize {
 		return nil, ErrTxnTooBig
 	}

metrics_test.go

@@ -61,16 +61,16 @@ func TestWriteMetrics(t *testing.T) {
 		}
 
 		expectedSize := int64(len(val)) + 48 + 2 // 48 := size of key (40 + 8(ts)), 2 := meta
-		write_metric := expvar.Get("badger_v4_write_bytes_user")
+		write_metric := expvar.Get("badger_write_bytes_user")
 		require.Equal(t, expectedSize*int64(num), write_metric.(*expvar.Int).Value())
 
-		put_metric := expvar.Get("badger_v4_put_num_user")
+		put_metric := expvar.Get("badger_put_num_user")
 		require.Equal(t, int64(num), put_metric.(*expvar.Int).Value())
 
-		lsm_metric := expvar.Get("badger_v4_write_bytes_l0")
+		lsm_metric := expvar.Get("badger_write_bytes_l0")
 		require.Equal(t, expectedSize*int64(num), lsm_metric.(*expvar.Int).Value())
 
-		compactionMetric := expvar.Get("badger_v4_write_bytes_compaction").(*expvar.Map)
+		compactionMetric := expvar.Get("badger_write_bytes_compaction").(*expvar.Map)
 		require.Equal(t, nil, compactionMetric.Get("l6"))
 
 		// Force compaction
@@ -79,7 +79,7 @@ func TestWriteMetrics(t *testing.T) {
 		_, err := OpenManaged(opt)
 		require.NoError(t, err)
 
-		compactionMetric = expvar.Get("badger_v4_write_bytes_compaction").(*expvar.Map)
+		compactionMetric = expvar.Get("badger_write_bytes_compaction").(*expvar.Map)
 		require.GreaterOrEqual(t, expectedSize*int64(num)+int64(num*200), compactionMetric.Get("l6").(*expvar.Int).Value())
 		// Because we have random values, compression is not able to do much, so we incur a cost on total size
 	})
@@ -107,10 +107,10 @@ func TestVlogMetrics(t *testing.T) {
 
 		expectedSize := int64(len(val)) + 200 // vlog expected size
 
-		totalWrites := expvar.Get("badger_v4_write_num_vlog")
+		totalWrites := expvar.Get("badger_write_num_vlog")
 		require.Equal(t, int64(num), totalWrites.(*expvar.Int).Value())
 
-		bytesWritten := expvar.Get("badger_v4_write_bytes_vlog")
+		bytesWritten := expvar.Get("badger_write_bytes_vlog")
 		require.GreaterOrEqual(t, expectedSize*int64(num), bytesWritten.(*expvar.Int).Value())
 
 		txn := db.NewTransactionAt(2, false)
@@ -119,8 +119,8 @@ func TestVlogMetrics(t *testing.T) {
 		require.Equal(t, uint64(1), item.Version())
 
 		err = item.Value(func(val []byte) error {
-			totalReads := expvar.Get("badger_v4_read_num_vlog")
-			bytesRead := expvar.Get("badger_v4_read_bytes_vlog")
+			totalReads := expvar.Get("badger_read_num_vlog")
+			bytesRead := expvar.Get("badger_read_bytes_vlog")
 			require.Equal(t, int64(1), totalReads.(*expvar.Int).Value())
 			require.GreaterOrEqual(t, expectedSize, bytesRead.(*expvar.Int).Value())
 			return nil
@@ -156,13 +156,13 @@ func TestReadMetrics(t *testing.T) {
 		require.NoError(t, err)
 		require.Equal(t, uint64(1), item.Version())
 
-		totalGets := expvar.Get("badger_v4_get_num_user")
+		totalGets := expvar.Get("badger_get_num_user")
 		require.Equal(t, int64(1), totalGets.(*expvar.Int).Value())
 
-		totalMemtableReads := expvar.Get("badger_v4_get_num_memtable")
+		totalMemtableReads := expvar.Get("badger_get_num_memtable")
 		require.Equal(t, int64(1), totalMemtableReads.(*expvar.Int).Value())
 
-		totalLSMGets := expvar.Get("badger_v4_get_num_lsm")
+		totalLSMGets := expvar.Get("badger_get_num_lsm")
 		require.Nil(t, totalLSMGets.(*expvar.Map).Get("l6"))
 
 		// Force compaction
@@ -179,25 +179,25 @@ func TestReadMetrics(t *testing.T) {
 		_, err = txn.Get([]byte(key("abdbyte", 1000))) // val should be far enough that bloom filter doesn't hit
 		require.Error(t, err)
 
-		totalLSMGets = expvar.Get("badger_v4_get_num_lsm")
+		totalLSMGets = expvar.Get("badger_get_num_lsm")
 		require.Equal(t, int64(0x1), totalLSMGets.(*expvar.Map).Get("l6").(*expvar.Int).Value())
 
-		totalBloom := expvar.Get("badger_v4_hit_num_lsm_bloom_filter")
+		totalBloom := expvar.Get("badger_hit_num_lsm_bloom_filter")
 		require.Equal(t, int64(0x1), totalBloom.(*expvar.Map).Get("l6").(*expvar.Int).Value())
 		require.Equal(t, int64(0x1), totalBloom.(*expvar.Map).Get("DoesNotHave_HIT").(*expvar.Int).Value())
 		require.Equal(t, int64(0x2), totalBloom.(*expvar.Map).Get("DoesNotHave_ALL").(*expvar.Int).Value())
 
-		bytesLSM := expvar.Get("badger_v4_read_bytes_lsm")
+		bytesLSM := expvar.Get("badger_read_bytes_lsm")
 		require.Equal(t, int64(len(val)), bytesLSM.(*expvar.Int).Value())
 
-		getWithResult := expvar.Get("badger_v4_get_with_result_num_user")
+		getWithResult := expvar.Get("badger_get_with_result_num_user")
 		require.Equal(t, int64(2), getWithResult.(*expvar.Int).Value())
 
 		iterOpts := DefaultIteratorOptions
 		iter := txn.NewKeyIterator(keys[0], iterOpts)
 		iter.Seek(keys[0])
 
-		rangeQueries := expvar.Get("badger_v4_iterator_num_user")
+		rangeQueries := expvar.Get("badger_iterator_num_user")
 		require.Equal(t, int64(1), rangeQueries.(*expvar.Int).Value())
 	})
 }

y/metrics.go

@@ -21,7 +21,7 @@ import (
 )
 
 const (
-	BADGER_METRIC_PREFIX = "badger_v4_"
+	BADGER_METRIC_PREFIX = "badger_"
 )
 
 var (