feat: make batch_size_ranges configuration optional by providing hardcoded defaults

Signed-off-by: OneZero-Y <[email protected]>

Author: OneZero-Y

config/config.yaml

@@ -253,15 +253,6 @@ api:
       high_resolution_timing: false      # Use nanosecond precision timing 
       sample_rate: 1.0                   # Collect metrics for all requests (1.0 = 100%, 0.5 = 50%)
 
-      # Batch size range labels for metrics (used in duration metrics labels)
-      batch_size_ranges:
-        - {min: 1, max: 1, label: "1"}
-        - {min: 2, max: 5, label: "2-5"}
-        - {min: 6, max: 10, label: "6-10"}
-        - {min: 11, max: 20, label: "11-20"}
-        - {min: 21, max: 50, label: "21-50"}
-        - {min: 51, max: -1, label: "50+"}  # -1 means no upper limit
-      
       # Histogram buckets for metrics (directly configure what you need)
       duration_buckets: [0.001, 0.005, 0.01, 0.025, 0.05, 0.1, 0.25, 0.5, 1, 2.5, 5, 10, 30]
       size_buckets: [1, 2, 5, 10, 20, 50, 100, 200]     

src/semantic-router/pkg/config/config.go

@@ -105,7 +105,8 @@ type BatchClassificationMetricsConfig struct {
 	// Sample rate for metrics collection (0.0-1.0, 1.0 means collect all metrics)
 	SampleRate float64 `yaml:"sample_rate,omitempty"`
 
-	// Batch size range labels for metrics
+	// Batch size range labels for metrics (optional - uses sensible defaults if not specified)
+	// Default ranges: "1", "2-5", "6-10", "11-20", "21-50", "50+"
 	BatchSizeRanges []BatchSizeRangeConfig `yaml:"batch_size_ranges,omitempty"`
 
 	// Histogram buckets for metrics (directly configured)

src/semantic-router/pkg/metrics/metrics_test.go

@@ -166,3 +166,92 @@ func TestMetricsIntegration(t *testing.T) {
 		ConcurrentGoroutines.WithLabelValues(batchID).Dec()
 	}
 }
+
+// TestDefaultBatchSizeRanges tests that default batch size ranges work when configuration is empty
+func TestDefaultBatchSizeRanges(t *testing.T) {
+	// Save current config
+	originalConfig := GetBatchMetricsConfig()
+
+	// Set config with empty BatchSizeRanges to test defaults
+	emptyConfig := BatchMetricsConfig{
+		Enabled:                   true,
+		DetailedGoroutineTracking: true,
+		HighResolutionTiming:      false,
+		SampleRate:                1.0,
+		DurationBuckets:           FallbackDurationBuckets,
+		SizeBuckets:               FallbackSizeBuckets,
+		BatchSizeRanges:           []config.BatchSizeRangeConfig{}, // Empty - should use defaults
+	}
+	SetBatchMetricsConfig(emptyConfig)
+
+	// Test that default ranges are used
+	tests := []struct {
+		name     string
+		size     int
+		expected string
+	}{
+		{"Single text (default)", 1, "1"},
+		{"Small batch (default)", 3, "2-5"},
+		{"Medium batch (default)", 8, "6-10"},
+		{"Large batch (default)", 15, "11-20"},
+		{"Very large batch (default)", 35, "21-50"},
+		{"Maximum batch (default)", 100, "50+"},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := GetBatchSizeRange(tt.size)
+			if result != tt.expected {
+				t.Errorf("GetBatchSizeRange(%d) with empty config = %s, want %s", tt.size, result, tt.expected)
+			}
+		})
+	}
+
+	// Restore original config
+	SetBatchMetricsConfig(originalConfig)
+}
+
+// TestCustomBatchSizeRanges tests that custom batch size ranges override defaults
+func TestCustomBatchSizeRanges(t *testing.T) {
+	// Save current config
+	originalConfig := GetBatchMetricsConfig()
+
+	// Set config with custom BatchSizeRanges
+	customConfig := BatchMetricsConfig{
+		Enabled:                   true,
+		DetailedGoroutineTracking: true,
+		HighResolutionTiming:      false,
+		SampleRate:                1.0,
+		DurationBuckets:           FallbackDurationBuckets,
+		SizeBuckets:               FallbackSizeBuckets,
+		BatchSizeRanges: []config.BatchSizeRangeConfig{
+			{Min: 1, Max: 10, Label: "small"},
+			{Min: 11, Max: 100, Label: "medium"},
+			{Min: 101, Max: -1, Label: "large"},
+		},
+	}
+	SetBatchMetricsConfig(customConfig)
+
+	// Test that custom ranges are used
+	tests := []struct {
+		name     string
+		size     int
+		expected string
+	}{
+		{"Custom small range", 5, "small"},
+		{"Custom medium range", 50, "medium"},
+		{"Custom large range", 200, "large"},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := GetBatchSizeRange(tt.size)
+			if result != tt.expected {
+				t.Errorf("GetBatchSizeRange(%d) with custom config = %s, want %s", tt.size, result, tt.expected)
+			}
+		})
+	}
+
+	// Restore original config
+	SetBatchMetricsConfig(originalConfig)
+}

website/docs/getting-started/configuration.md

@@ -233,14 +233,16 @@ api:
       high_resolution_timing: false      # Use nanosecond precision timing
       sample_rate: 1.0                   # Collect metrics for all requests (1.0 = 100%)
 
-      # Batch size range labels for metrics
-      batch_size_ranges:
-        - {min: 1, max: 1, label: "1"}
-        - {min: 2, max: 5, label: "2-5"}
-        - {min: 6, max: 10, label: "6-10"}
-        - {min: 11, max: 20, label: "11-20"}
-        - {min: 21, max: 50, label: "21-50"}
-        - {min: 51, max: -1, label: "50+"}  # -1 means no upper limit
+      # Batch size range labels for metrics (OPTIONAL - uses sensible defaults)
+      # Default ranges: "1", "2-5", "6-10", "11-20", "21-50", "50+"
+      # Only specify if you need custom ranges:
+      # batch_size_ranges:
+      #   - {min: 1, max: 1, label: "1"}
+      #   - {min: 2, max: 5, label: "2-5"}
+      #   - {min: 6, max: 10, label: "6-10"}
+      #   - {min: 11, max: 20, label: "11-20"}
+      #   - {min: 21, max: 50, label: "21-50"}
+      #   - {min: 51, max: -1, label: "50+"}  # -1 means no upper limit
 
       # Histogram buckets - choose from presets below or customize
       duration_buckets: [0.001, 0.005, 0.01, 0.025, 0.05, 0.1, 0.25, 0.5, 1, 2.5, 5, 10, 30]
@@ -282,37 +284,43 @@ pkill -f "router"
 make run-router
 ```
 
+### Default Batch Size Ranges
+
+The system provides sensible default batch size ranges that work well for most use cases:
+
+- **"1"** - Single text requests
+- **"2-5"** - Small batch requests  
+- **"6-10"** - Medium batch requests
+- **"11-20"** - Large batch requests
+- **"21-50"** - Very large batch requests
+- **"50+"** - Maximum batch requests
+
+**You don't need to configure `batch_size_ranges` unless you have specific requirements.** The defaults are automatically used when the configuration is omitted.
+
 ### Configuration Examples by Use Case
 
 **Real-time Chat API (fast preset)**
 ```yaml
 # Copy these values to your config for sub-millisecond monitoring
 duration_buckets: [0.0001, 0.0005, 0.001, 0.005, 0.01, 0.05, 0.1]
 size_buckets: [1, 2, 3, 5, 8, 10]
-batch_size_ranges:
-  - {min: 1, max: 1, label: "1"}
-  - {min: 2, max: 5, label: "2-5"}
-  - {min: 6, max: -1, label: "6+"}
+# batch_size_ranges: uses defaults (no configuration needed)
 ```
 
 **E-commerce API (standard preset)**
 ```yaml
 # Copy these values for typical web API response times
 duration_buckets: [0.001, 0.005, 0.01, 0.025, 0.05, 0.1, 0.25, 0.5, 1, 2.5, 5, 10]
 size_buckets: [1, 2, 5, 10, 20, 50, 100]
-batch_size_ranges:
-  - {min: 1, max: 1, label: "1"}
-  - {min: 2, max: 5, label: "2-5"}
-  - {min: 6, max: 10, label: "6-10"}
-  - {min: 11, max: 20, label: "11-20"}
-  - {min: 21, max: -1, label: "21+"}
+# batch_size_ranges: uses defaults (no configuration needed)
 ```
 
 **Data Processing Pipeline (slow preset)**
 ```yaml
 # Copy these values for heavy computation workloads
 duration_buckets: [0.1, 0.5, 1, 5, 10, 30, 60, 120]
 size_buckets: [10, 50, 100, 500, 1000, 5000]
+# Custom batch size ranges for large-scale processing (overrides defaults)
 batch_size_ranges:
   - {min: 1, max: 50, label: "1-50"}
   - {min: 51, max: 200, label: "51-200"}