Add benchmarks to compare text and protobuf parsing.

Author: Bjoern Rabenstein

text/bench_test.go

@@ -0,0 +1,165 @@
+// Copyright 2015 The Prometheus Authors
+// 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 text
+
+import (
+	"bytes"
+	"compress/gzip"
+	"io"
+	"io/ioutil"
+	"testing"
+
+	dto "github.com/prometheus/client_model/go"
+
+	"github.com/matttproud/golang_protobuf_extensions/ext"
+)
+
+// Benchmarks to show how much penalty text format parsing accually inflicts.
+//
+// Example results on Linux 3.13.0, Intel(R) Core(TM) i7-4700MQ CPU @ 2.40GHz, go1.4.
+//
+// BenchmarkParseText          1000           1188535 ns/op          205085 B/op       6135 allocs/op
+// BenchmarkParseTextGzip      1000           1376567 ns/op          246224 B/op       6151 allocs/op
+// BenchmarkParseProto        10000            172790 ns/op           52258 B/op       1160 allocs/op
+// BenchmarkParseProtoGzip     5000            324021 ns/op           94931 B/op       1211 allocs/op
+// BenchmarkParseProtoMap     10000            187946 ns/op           58714 B/op       1203 allocs/op
+//
+// CONCLUSION: The overhead for the map is negligible. Text format needs ~5x more allocations.
+// Without compression, it needs ~7x longer, but with compression (the more relevant scenario),
+// the difference becomes less relevant, only ~4x.
+//
+// The test data contains 248 samples.
+
+// BenchmarkParseText benchmarks the parsing of a text-format scrape into metric
+// family DTOs.
+func BenchmarkParseText(b *testing.B) {
+	b.StopTimer()
+	data, err := ioutil.ReadFile("testdata/text")
+	if err != nil {
+		b.Fatal(err)
+	}
+	b.StartTimer()
+
+	for i := 0; i < b.N; i++ {
+		if _, err := parser.TextToMetricFamilies(bytes.NewReader(data)); err != nil {
+			b.Fatal(err)
+		}
+	}
+}
+
+// BenchmarkParseTextGzip benchmarks the parsing of a gzipped text-format scrape
+// into metric family DTOs.
+func BenchmarkParseTextGzip(b *testing.B) {
+	b.StopTimer()
+	data, err := ioutil.ReadFile("testdata/text.gz")
+	if err != nil {
+		b.Fatal(err)
+	}
+	b.StartTimer()
+
+	for i := 0; i < b.N; i++ {
+		in, err := gzip.NewReader(bytes.NewReader(data))
+		if err != nil {
+			b.Fatal(err)
+		}
+		if _, err := parser.TextToMetricFamilies(in); err != nil {
+			b.Fatal(err)
+		}
+	}
+}
+
+// BenchmarkParseProto benchmarks the parsinge of a protobuf-format scrape into
+// metric family DTOs. Note that this does not build a map of matric families
+// (as the text version does), because it is not required for Prometheus
+// ingestion either. (However, it is required for the text-format parsing, as
+// the metric family might be sprinkled all over the text, while the
+// protobuf-format guarantees bundling at one place.)
+func BenchmarkParseProto(b *testing.B) {
+	b.StopTimer()
+	data, err := ioutil.ReadFile("testdata/protobuf")
+	if err != nil {
+		b.Fatal(err)
+	}
+	b.StartTimer()
+
+	for i := 0; i < b.N; i++ {
+		family := &dto.MetricFamily{}
+		in := bytes.NewReader(data)
+		for {
+			family.Reset()
+			if _, err := ext.ReadDelimited(in, family); err != nil {
+				if err == io.EOF {
+					break
+				}
+				b.Fatal(err)
+			}
+		}
+	}
+}
+
+// BenchmarkParseProtoGzip is like BenchmarkParseProto above, but parses gzipped
+// protobuf format.
+func BenchmarkParseProtoGzip(b *testing.B) {
+	b.StopTimer()
+	data, err := ioutil.ReadFile("testdata/protobuf.gz")
+	if err != nil {
+		b.Fatal(err)
+	}
+	b.StartTimer()
+
+	for i := 0; i < b.N; i++ {
+		family := &dto.MetricFamily{}
+		in, err := gzip.NewReader(bytes.NewReader(data))
+		if err != nil {
+			b.Fatal(err)
+		}
+		for {
+			family.Reset()
+			if _, err := ext.ReadDelimited(in, family); err != nil {
+				if err == io.EOF {
+					break
+				}
+				b.Fatal(err)
+			}
+		}
+	}
+}
+
+// BenchmarkParseProtoMap is like BenchmarkParseProto but DOES put the parsed
+// metric family DTOs into a map. This is not happening during Prometheus
+// ingestion. It is just here to measure the overhead of that map creation and
+// separate it from the overhead of the text format parsing.
+func BenchmarkParseProtoMap(b *testing.B) {
+	b.StopTimer()
+	data, err := ioutil.ReadFile("testdata/protobuf")
+	if err != nil {
+		b.Fatal(err)
+	}
+	b.StartTimer()
+
+	for i := 0; i < b.N; i++ {
+		families := map[string]*dto.MetricFamily{}
+		in := bytes.NewReader(data)
+		for {
+			family := &dto.MetricFamily{}
+			if _, err := ext.ReadDelimited(in, family); err != nil {
+				if err == io.EOF {
+					break
+				}
+				b.Fatal(err)
+			}
+			families[family.GetName()] = family
+		}
+	}
+}