test: add benchmark for OTel Beat processor (#48407) (#48409)

(cherry picked from commit 03fff9b)

Co-authored-by: Andrzej Stencel <andrzej.stencel@elastic.co>

Author: mergify[bot]

x-pack/otel/processor/beatprocessor/benchmark_test.go

@@ -0,0 +1,114 @@
+// Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+// or more contributor license agreements. Licensed under the Elastic License;
+// you may not use this file except in compliance with the Elastic License.
+
+package beatprocessor
+
+import (
+	"context"
+	"fmt"
+	"testing"
+
+	"github.com/elastic/beats/v7/libbeat/beat"
+
+	"go.opentelemetry.io/collector/pdata/plog"
+	"go.uber.org/zap"
+)
+
+// Runs the OTel Beat processor with a no-op processor inside
+// to measure the overhead of the OTel processor itself.
+func BenchmarkBeatProcessor(b *testing.B) {
+	testCases := []testCase{
+		{
+			name: "empty log record",
+			logRecord: func() plog.LogRecord {
+				logRecord := plog.NewLogRecord()
+				logRecord.Body().SetEmptyMap()
+				return logRecord
+			},
+		},
+		{
+			name: "message",
+			logRecord: func() plog.LogRecord {
+				logRecord := plog.NewLogRecord()
+				logRecord.Body().SetEmptyMap()
+				logRecord.Body().Map().PutStr("message", "test log message")
+				return logRecord
+			},
+		},
+		{
+			name: "Kubernetes log",
+			logRecord: func() plog.LogRecord {
+				logRecord := plog.NewLogRecord()
+				logRecord.Body().SetEmptyMap()
+				logRecord.Body().Map().PutStr("time", "2026-01-13T13:01:05.551185505Z")
+				logRecord.Body().Map().PutStr("stream", "stderr")
+				logRecord.Body().Map().PutStr("log", "W0113 13:01:05.550863       1 warnings.go:70] v1 Endpoints is deprecated in v1.33+; use discovery.k8s.io/v1 EndpointSlice")
+				return logRecord
+			},
+		},
+		{
+			name: "Nginx access log",
+			logRecord: func() plog.LogRecord {
+				logRecord := plog.NewLogRecord()
+				logRecord.Body().SetEmptyMap()
+				logRecord.Body().Map().PutStr("timestamp", "2025-10-05T13:33:14+00:00")
+				logRecord.Body().Map().PutStr("pid", "30")
+				logRecord.Body().Map().PutStr("client_ip", "172.19.0.1")
+				logRecord.Body().Map().PutStr("request_id", "72e5a0eeb44b6608d161254a5eaf1662")
+				logRecord.Body().Map().PutStr("http_method", "GET")
+				logRecord.Body().Map().PutStr("http_path", "/")
+				logRecord.Body().Map().PutStr("protocol", "HTTP/1.1")
+				logRecord.Body().Map().PutStr("host", "localhost")
+				logRecord.Body().Map().PutStr("user_agent", "curl/8.5.0")
+				logRecord.Body().Map().PutStr("referer", "")
+				logRecord.Body().Map().PutInt("status_code", 200)
+				logRecord.Body().Map().PutInt("bytes_sent", 615)
+				logRecord.Body().Map().PutDouble("request_time_secs", 0.01)
+				return logRecord
+			},
+		},
+	}
+
+	benchmarkBeatProcessor(b, 0, testCases[0])
+
+	for _, tc := range testCases {
+		for _, logCount := range []int{1, 1000} {
+			benchmarkBeatProcessor(b, logCount, tc)
+		}
+	}
+}
+
+func benchmarkBeatProcessor(b *testing.B, logCount int, tc testCase) {
+	b.Run(fmt.Sprintf("%s/%d_logs", tc.name, logCount), func(b *testing.B) {
+		// Prepare logs.
+		logs := plog.NewLogs()
+		resourceLogs := logs.ResourceLogs().AppendEmpty()
+		scopeLogs := resourceLogs.ScopeLogs().AppendEmpty()
+		for range logCount {
+			logRecord := scopeLogs.LogRecords().AppendEmpty()
+			tc.logRecord().CopyTo(logRecord)
+		}
+
+		// Create Beat processor with a no-op processor inside.
+		beatProcessor := &beatProcessor{
+			logger: zap.NewNop(),
+			processors: []beat.Processor{
+				mockProcessor{
+					runFunc: func(event *beat.Event) (*beat.Event, error) {
+						return event, nil
+					},
+				},
+			},
+		}
+
+		for b.Loop() {
+			_, _ = beatProcessor.ConsumeLogs(context.Background(), logs)
+		}
+	})
+}
+
+type testCase struct {
+	name      string
+	logRecord func() plog.LogRecord
+}