feat: Increase drain max depth from 8 -> 30 (#13063)

pkg/pattern/drain/drain.go

@@ -130,7 +130,7 @@ func DefaultConfig() *Config {
 		//  > message are more likely to be constants. Specifically, Drain
 		//  > selects the next internal node by the tokens in the beginning
 		//  > positions of the log message
-		LogClusterDepth: 8,
+		LogClusterDepth: 30,
 		// SimTh is basically a ratio of matching/total in the cluster.
 		// Cluster tokens: "foo <*> bar fred"
 		//       Log line: "foo bar baz qux"

pkg/pattern/drain/drain_benchmark_test.go

@@ -0,0 +1,78 @@
+package drain
+
+import (
+	"bufio"
+	"os"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func BenchmarkDrain_TrainExtractsPatterns(b *testing.B) {
+	tests := []struct {
+		name      string
+		drain     *Drain
+		inputFile string
+	}{
+		{
+			name:      `Patterns for agent logfmt logs`,
+			inputFile: `testdata/agent-logfmt.txt`,
+		},
+		{
+			name:      `Patterns for ingester logfmt logs`,
+			inputFile: `testdata/ingester-logfmt.txt`,
+		},
+		{
+			name:      `Patterns for Drone json logs`,
+			inputFile: `testdata/drone-json.txt`,
+		},
+		{
+			name:      "Patterns for distributor logfmt logs",
+			inputFile: "testdata/distributor-logfmt.txt",
+		},
+		{
+			name:      "Patterns for journald logs",
+			inputFile: "testdata/journald.txt",
+		},
+		{
+			name:      "Patterns for kafka logs",
+			inputFile: "testdata/kafka.txt",
+		},
+		{
+			name:      "Patterns for kubernetes logs",
+			inputFile: "testdata/kubernetes.txt",
+		},
+		{
+			name:      "Patterns for vault logs",
+			inputFile: "testdata/vault.txt",
+		},
+		{
+			name:      "Patterns for calico logs",
+			inputFile: "testdata/calico.txt",
+		},
+	}
+
+	for _, tt := range tests {
+		b.Run(tt.name, func(b *testing.B) {
+			file, err := os.Open(tt.inputFile)
+			require.NoError(b, err)
+			defer file.Close()
+
+			scanner := bufio.NewScanner(file)
+			var lines []string
+			for scanner.Scan() {
+				line := scanner.Text()
+				lines = append(lines, line)
+			}
+
+			b.ReportAllocs()
+			b.ResetTimer()
+			for i := 0; i < b.N; i++ {
+				for _, line := range lines {
+					drain := New(DefaultConfig(), nil)
+					drain.Train(line, 0)
+				}
+			}
+		})
+	}
+}