Change unit of ops and file-cache latency metrics to microseconds

internal/fs/wrappers/monitoring.go

@@ -22,6 +22,7 @@ import (
 	"time"
 
 	"github.com/googlecloudplatform/gcsfuse/v2/internal/logger"
+	"github.com/googlecloudplatform/gcsfuse/v2/internal/monitor"
 	"github.com/googlecloudplatform/gcsfuse/v2/internal/monitor/tags"
 	"github.com/jacobsa/fuse/fuseops"
 	"github.com/jacobsa/fuse/fuseutil"
@@ -38,9 +39,9 @@ import (
 const name = "cloud.google.com/gcsfuse"
 
 var (
-	opsCount      = stats.Int64("fs/ops_count", "The number of ops processed by the file system.", stats.UnitDimensionless)
-	opsLatency    = stats.Float64("fs/ops_latency", "The latency of a file system operation.", stats.UnitMilliseconds)
-	opsErrorCount = stats.Int64("fs/ops_error_count", "The number of errors generated by file system operation.", stats.UnitDimensionless)
+	opsCount      = stats.Int64("fs/ops_count", "The number of ops processed by the file system.", monitor.UnitDimensionless)
+	opsLatency    = stats.Int64("fs/ops_latency", "The latency of a file system operation.", monitor.UnitMicroseconds)
+	opsErrorCount = stats.Int64("fs/ops_error_count", "The number of errors generated by file system operation.", monitor.UnitDimensionless)
 
 	tracer = otel.Tracer(name)
 )
@@ -292,13 +293,12 @@ func recordOp(ctx context.Context, method string, start time.Time, fsErr error)
 	}
 
 	// Recording opLatency.
-	latencyMs := float64(time.Since(start).Microseconds()) / 1000.0
 	if err := stats.RecordWithTags(
 		ctx,
 		[]tag.Mutator{
 			tag.Upsert(tags.FSOp, method),
 		},
-		opsLatency.M(latencyMs),
+		opsLatency.M(time.Since(start).Microseconds()),
 	); err != nil {
 		// Error in opLatency.
 		logger.Errorf("Cannot record file system operation latency: %v", err)

internal/gcsx/random_reader.go

@@ -202,7 +202,7 @@ func (rr *randomReader) tryReadingFromFileCache(ctx context.Context,
 			readType = util.Sequential
 		}
 		// Capture file cache metrics to be exported via stackdriver
-		monitor.CaptureFileCacheMetrics(ctx, readType, n, cacheHit, executionTime.Nanoseconds())
+		monitor.CaptureFileCacheMetrics(ctx, readType, n, cacheHit, executionTime)
 	}()
 
 	// Create fileCacheHandle if not already.

internal/monitor/reader.go

@@ -17,6 +17,7 @@ package monitor
 import (
 	"log"
 	"strconv"
+	"time"
 
 	"github.com/googlecloudplatform/gcsfuse/v2/internal/logger"
 	"github.com/googlecloudplatform/gcsfuse/v2/internal/monitor/tags"
@@ -34,19 +35,19 @@ var (
 	// This metric captures only the requests made to GCS, not the subsequent page calls.
 	gcsReadCount = stats.Int64("gcs/read_count",
 		"Specifies the number of gcs reads made along with type - Sequential/Random",
-		stats.UnitDimensionless)
+		UnitDimensionless)
 	downloadBytesCount = stats.Int64("gcs/download_bytes_count",
 		"The cumulative number of bytes downloaded from GCS along with type - Sequential/Random",
-		stats.UnitBytes)
+		UnitBytes)
 	fileCacheReadCount = stats.Int64("file_cache/read_count",
 		"Specifies the number of read requests made via file cache along with type - Sequential/Random and cache hit - true/false",
-		stats.UnitDimensionless)
+		UnitDimensionless)
 	fileCacheReadBytesCount = stats.Int64("file_cache/read_bytes_count",
 		"The cumulative number of bytes read from file cache along with read type - Sequential/Random",
-		stats.UnitBytes)
-	fileCacheReadLatency = stats.Float64("file_cache/read_latency",
+		UnitBytes)
+	fileCacheReadLatency = stats.Int64("file_cache/read_latency",
 		"Latency of read from file cache along with cache hit - true/false",
-		stats.UnitMilliseconds)
+		UnitMicroseconds)
 )
 
 const NanosecondsInOneMillisecond = 1000000
@@ -120,7 +121,7 @@ func CaptureGCSReadMetrics(ctx context.Context, readType string, requestedDataSi
 	}
 }
 
-func CaptureFileCacheMetrics(ctx context.Context, readType string, readDataSize int, cacheHit bool, readLatencyNs int64) {
+func CaptureFileCacheMetrics(ctx context.Context, readType string, readDataSize int, cacheHit bool, readLatency time.Duration) {
 	if err := stats.RecordWithTags(
 		ctx,
 		[]tag.Mutator{
@@ -144,13 +145,12 @@ func CaptureFileCacheMetrics(ctx context.Context, readType string, readDataSize
 		logger.Errorf("Cannot record fileCacheReadBytesCount %v", err)
 	}
 
-	readLatencyMs := float64(readLatencyNs) / float64(NanosecondsInOneMillisecond)
 	if err := stats.RecordWithTags(
 		ctx,
 		[]tag.Mutator{
 			tag.Upsert(tags.CacheHit, strconv.FormatBool(cacheHit)),
 		},
-		fileCacheReadLatency.M(readLatencyMs),
+		fileCacheReadLatency.M(readLatency.Microseconds()),
 	); err != nil {
 		// Error in recording fileCacheReadLatency.
 		logger.Errorf("Cannot record fileCacheReadLatency %v", err)

internal/monitor/units.go

@@ -0,0 +1,23 @@
+// Copyright 2024 Google LLC
+//
+// 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 monitor
+
+import "go.opencensus.io/stats"
+
+const (
+	UnitDimensionless = stats.UnitDimensionless
+	UnitMicroseconds  = "us"
+	UnitBytes         = stats.UnitBytes
+)