Fix unit suffix duplication in Prometheus metrics (#1153)

Author: danbarr

pkg/telemetry/integration_test.go

@@ -151,8 +151,8 @@ func TestTelemetryIntegration_EndToEnd(t *testing.T) {
 
 		// If we have custom metrics, verify them
 		if strings.Contains(metricsBody, "toolhive_mcp") {
-			assert.Contains(t, metricsBody, "toolhive_mcp_requests_total")
-			assert.Contains(t, metricsBody, "toolhive_mcp_request_duration_seconds")
+			assert.Contains(t, metricsBody, "toolhive_mcp_requests")
+			assert.Contains(t, metricsBody, "toolhive_mcp_request_duration")
 			assert.Contains(t, metricsBody, "toolhive_mcp_active_connections")
 		}
 	} else {
@@ -259,7 +259,7 @@ func TestTelemetryIntegration_WithRealProviders(t *testing.T) {
 	for _, sm := range rm.ScopeMetrics {
 		for _, metric := range sm.Metrics {
 			switch metric.Name {
-			case "toolhive_mcp_requests_total":
+			case "toolhive_mcp_requests":
 				foundRequestCounter = true
 				// Verify metric has expected attributes
 				if sum, ok := metric.Data.(metricdata.Sum[int64]); ok {
@@ -281,7 +281,7 @@ func TestTelemetryIntegration_WithRealProviders(t *testing.T) {
 						assert.True(t, hasMethod, "Request counter should have mcp_method attribute")
 					}
 				}
-			case "toolhive_mcp_request_duration_seconds":
+			case "toolhive_mcp_request_duration":
 				foundDurationHistogram = true
 			case "toolhive_mcp_active_connections":
 				foundActiveConnections = true
@@ -404,7 +404,7 @@ func TestTelemetryIntegration_ToolSpecificMetrics(t *testing.T) {
 	var foundToolCounter bool
 	for _, sm := range rm.ScopeMetrics {
 		for _, metric := range sm.Metrics {
-			if metric.Name == "toolhive_mcp_tool_calls_total" {
+			if metric.Name == "toolhive_mcp_tool_calls" {
 				foundToolCounter = true
 				if sum, ok := metric.Data.(metricdata.Sum[int64]); ok {
 					assert.NotEmpty(t, sum.DataPoints)
@@ -480,6 +480,6 @@ func TestTelemetryIntegration_MultipleRequests(t *testing.T) {
 
 	// The exact count format depends on Prometheus exposition format
 	// We just verify the metrics are present and contain our server name
-	assert.Contains(t, metricsBody, "toolhive_mcp_requests_total")
+	assert.Contains(t, metricsBody, "toolhive_mcp_requests")
 	assert.Contains(t, metricsBody, `server="multi-test"`)
 }

pkg/telemetry/middleware.go

@@ -53,12 +53,12 @@ func NewHTTPMiddleware(
 
 	// Initialize metrics
 	requestCounter, _ := meter.Int64Counter(
-		"toolhive_mcp_requests_total",
+		"toolhive_mcp_requests", // The exporter adds the _total suffix automatically
 		metric.WithDescription("Total number of MCP requests"),
 	)
 
 	requestDuration, _ := meter.Float64Histogram(
-		"toolhive_mcp_request_duration_seconds",
+		"toolhive_mcp_request_duration", // The exporter adds the _seconds suffix automatically
 		metric.WithDescription("Duration of MCP requests in seconds"),
 		metric.WithUnit("s"),
 	)
@@ -449,7 +449,7 @@ func (m *HTTPMiddleware) recordMetrics(ctx context.Context, r *http.Request, rw
 
 			// Record tool-specific counter
 			if toolCounter, err := m.meter.Int64Counter(
-				"toolhive_mcp_tool_calls_total",
+				"toolhive_mcp_tool_calls", // The exporter adds the _total suffix automatically
 				metric.WithDescription("Total number of MCP tool calls"),
 			); err == nil {
 				toolCounter.Add(ctx, 1, toolAttrs)

pkg/telemetry/middleware_sse_test.go

@@ -118,7 +118,7 @@ func TestHTTPMiddleware_RecordSSEConnection(t *testing.T) {
 	meter := meterProvider.Meter(instrumentationName)
 
 	requestCounter, _ := meter.Int64Counter(
-		"toolhive_mcp_requests_total",
+		"toolhive_mcp_requests",
 		metric.WithDescription("Total number of MCP requests"),
 	)
 

pkg/telemetry/middleware_test.go

@@ -655,9 +655,9 @@ func TestHTTPMiddleware_WithRealMetrics(t *testing.T) {
 	for _, sm := range rm.ScopeMetrics {
 		for _, metric := range sm.Metrics {
 			switch metric.Name {
-			case "toolhive_mcp_requests_total":
+			case "toolhive_mcp_requests":
 				foundCounter = true
-			case "toolhive_mcp_request_duration_seconds":
+			case "toolhive_mcp_request_duration":
 				foundHistogram = true
 			case "toolhive_mcp_active_connections":
 				foundGauge = true