fix(observability): fix top performers data loss, dead guards, display bugs, and response time unit conversion (#3794)

* fix metrics top performers panel data loss, dead guards, and display bugs

Signed-off-by: Shoumi <shoumimukherjee@gmail.com>

* convert avg_response_time seconds to ms in admin.js KPI and metrics cards

Signed-off-by: Shoumi <shoumimukherjee@gmail.com>

* update vitest assertions and prettier formatting for avg_response_time ms conversion

Signed-off-by: Shoumi <shoumimukherjee@gmail.com>

* fix: remove dead code from createPerformanceCard, fix CSV zero-value bug, add differential tests

- Remove unreachable avgResponseTime/lastExecutionTime branches from
  createPerformanceCard (its metrics list only has memory/CPU/disk/network keys)
- Fix CSV export treating avg_response_time=0 as N/A by using != null
  instead of truthiness check, consistent with table rendering
- Fix trailing whitespace in updateTableRows
- Update modularized test assertion for ×1000 conversion (150 → 150000)
- Add JS tests for createMetricsCard: seconds→ms conversion, ISO datetime
  formatting, null handling, zero-value preservation
- Add Python test verifying build_top_performers preserves 0.0 values

Closes #3793, Closes #3580

Signed-off-by: Mihai Criveti <crivetimihai@gmail.com>

---------

Signed-off-by: Shoumi <shoumimukherjee@gmail.com>
Signed-off-by: Mihai Criveti <crivetimihai@gmail.com>
Co-authored-by: Mihai Criveti <crivetimihai@gmail.com>

Author: 2 people

mcpgateway/admin_ui/metrics.js

@@ -774,7 +774,7 @@ export const extractKPIData = function (data) {
 
     const avgResponseTime =
       totalExecutions > 0 && weightedResponseSum > 0
-        ? weightedResponseSum / totalExecutions
+        ? (weightedResponseSum / totalExecutions) * 1000
         : null;
 
     const successRate =
@@ -1142,12 +1142,12 @@ item.executionCount || item.execution_count || item.executions || 0,
 );
 row.appendChild(execCell);
 
-// Avg Response Time
+// Avg Response Time (API returns seconds; convert to ms for display)
 const avgTimeCell = document.createElement("td");
 avgTimeCell.className =
 "px-6 py-4 whitespace-nowrap text-sm text-gray-500 dark:text-gray-300 sm:px-6 sm:py-4";
-const avgTime = item.avg_response_time || item.avgResponseTime;
-avgTimeCell.textContent = avgTime ? `${Math.round(avgTime)}ms` : "N/A";
+const avgTime = item.avg_response_time ?? item.avgResponseTime;
+avgTimeCell.textContent = avgTime != null ? `${Math.round(Number(avgTime) * 1000)}ms` : "N/A";
 row.appendChild(avgTimeCell);
 
 // Success Rate
@@ -1489,12 +1489,12 @@ export const updateTableRows = function (
     );
     row.appendChild(execCell);
 
-    // Avg Response Time
+    // Avg Response Time (API returns seconds; convert to ms for display)
     const avgTimeCell = document.createElement("td");
     avgTimeCell.className =
       "px-6 py-4 whitespace-nowrap text-sm text-gray-500 dark:text-gray-300 sm:px-6 sm:py-4";
-    const avgTime = item.avg_response_time || item.avgResponseTime;
-    avgTimeCell.textContent = avgTime ? `${Math.round(avgTime)}ms` : "N/A";
+    const avgTime = item.avg_response_time ?? item.avgResponseTime;
+    avgTimeCell.textContent = avgTime != null ? `${Math.round(Number(avgTime) * 1000)}ms` : "N/A";
     row.appendChild(avgTimeCell);
 
     // Success Rate
@@ -1554,8 +1554,8 @@ item.execution_count ||
 item.executions ||
 0,
 ),
-item.avg_response_time || item.avgResponseTime
-? `${Math.round(item.avg_response_time || item.avgResponseTime)}ms`
+(item.avg_response_time ?? item.avgResponseTime) != null
+? `${Math.round((item.avg_response_time ?? item.avgResponseTime) * 1000)}ms`
 : "N/A",
 `${calculateSuccessRate(item)}%`,
 formatLastUsed(item.last_execution || item.lastExecution),
@@ -1773,7 +1773,20 @@ export const createMetricsCard = function (title, metrics) {
 
     const valueSpan = document.createElement("span");
     valueSpan.className = "font-medium dark:text-gray-200";
-    valueSpan.textContent = value === "N/A" ? "N/A" : String(value);
+    let displayValue;
+    if (value === "N/A") {
+      displayValue = "N/A";
+    } else if (metric.key === "avgResponseTime") {
+      const ms = Number(value);
+      displayValue = isNaN(ms) ? "N/A" : `${(ms * 1000).toFixed(1)} ms`;
+    } else if (metric.key === "lastExecutionTime") {
+      displayValue = typeof value === "string" && value.includes("T")
+        ? value.slice(0, 16).replace("T", " ")
+        : String(value);
+    } else {
+      displayValue = String(value);
+    }
+    valueSpan.textContent = displayValue;
 
     metricRow.appendChild(label);
     metricRow.appendChild(valueSpan);

mcpgateway/templates/metrics_top_performers_partial.html

@@ -40,23 +40,27 @@
       </td>
       <td class="px-4 py-4 whitespace-nowrap text-sm text-gray-900 dark:text-gray-100">
         {% set avg_response = item.get('avgResponseTime') %}
-        {% if avg_response is not none and avg_response != 'N/A' %}
-          {{ "%.0f"|format(avg_response|float) }}ms
+        {% if avg_response is not none %}
+          {{ "%.0f"|format((avg_response|float) * 1000) }}ms
         {% else %}
           N/A
         {% endif %}
       </td>
       <td class="px-4 py-4 whitespace-nowrap text-sm">
-        {% set success_rate = item.get('successRate', 0) or 0 %}
+        {% set success_rate = item.get('successRate') %}
+        {% if success_rate is not none %}
         <span class="inline-flex items-center px-2.5 py-0.5 rounded-full text-xs font-semibold
           {% if success_rate >= 95 %}bg-green-100 text-green-800{% elif success_rate >= 80 %}bg-yellow-100 text-yellow-800{% else %}bg-red-100 text-red-800{% endif %}">
           {{ "%.1f"|format(success_rate) }}%
         </span>
+        {% else %}
+          N/A
+        {% endif %}
       </td>
       <td class="px-4 py-4 whitespace-nowrap text-sm text-gray-900 dark:text-gray-100">
         {% set last_exec = item.get('lastExecution') %}
-        {% if last_exec and last_exec != 'Never' %}
-          {{ last_exec }}
+        {% if last_exec %}
+          {{ last_exec[:16] | replace('T', ' ') }}
         {% else %}
           Never
         {% endif %}

mcpgateway/utils/metrics_common.py

@@ -57,8 +57,8 @@ def build_top_performers(results: List) -> List[TopPerformer]:
             id=result.id,
             name=result.name,
             execution_count=result.execution_count or 0,
-            avg_response_time=float(result.avg_response_time) if result.avg_response_time else None,
-            success_rate=float(result.success_rate) if result.success_rate else None,
+            avg_response_time=float(result.avg_response_time) if result.avg_response_time is not None else None,
+            success_rate=float(result.success_rate) if result.success_rate is not None else None,
             last_execution=result.last_execution,
         )
         for result in results

tests/js/admin-parsing.test.js

@@ -272,7 +272,7 @@ describe("extractKPIData", () => {
     expect(result.totalExecutions).toBe(100);
     expect(result.successRate).toBe(90);
     expect(result.errorRate).toBe(10);
-    expect(result.avgResponseTime).toBeCloseTo(1.5, 1);
+    expect(result.avgResponseTime).toBeCloseTo(1500, 1);
   });
 
   test("aggregates across multiple categories", () => {
@@ -362,8 +362,8 @@ describe("extractKPIData", () => {
       },
     };
     const result = extractKPIData(data);
-    // Weighted avg = (100*2.0 + 100*4.0) / 200 = 3.0
-    expect(result.avgResponseTime).toBeCloseTo(3.0, 1);
+    // Weighted avg = (100*2.0 + 100*4.0) / 200 = 3.0s = 3000ms
+    expect(result.avgResponseTime).toBeCloseTo(3000, 1);
   });
 
   test("ignores N/A response time values", () => {

tests/unit/js/metrics.test.js

@@ -609,7 +609,7 @@ describe("extractKPIData", () => {
     };
 
     const kpi = extractKPIData(data);
-    expect(kpi.avgResponseTime).toBe(150); // Weighted average
+    expect(kpi.avgResponseTime).toBe(150000); // Weighted average (seconds × 1000 → ms)
   });
 
   test("handles null avgResponseTime", () => {
@@ -825,6 +825,7 @@ describe("createPerformanceCard", () => {
     expect(card).toBeInstanceOf(HTMLElement);
     consoleError.mockRestore();
   });
+
 });
 
 describe("createRecentActivitySection", () => {
@@ -904,6 +905,31 @@ describe("createMetricsCard", () => {
     const card = createMetricsCard("Prompts", {});
     expect(card.textContent).toContain("N/A");
   });
+
+  test("converts avgResponseTime from seconds to milliseconds", () => {
+    const metrics = { avgResponseTime: 1.5 };
+    const card = createMetricsCard("Tools", metrics);
+    expect(card.textContent).toContain("1500.0 ms");
+  });
+
+  test("formats lastExecutionTime as human-readable date", () => {
+    const metrics = { lastExecutionTime: "2026-03-13T06:00:00.000000" };
+    const card = createMetricsCard("Tools", metrics);
+    expect(card.textContent).toContain("2026-03-13 06:00");
+  });
+
+  test("displays N/A for null avgResponseTime", () => {
+    const metrics = { avgResponseTime: null };
+    const card = createMetricsCard("Tools", metrics);
+    // avgResponseTime null → value resolves to "N/A" via ?? chain
+    expect(card.textContent).toContain("N/A");
+  });
+
+  test("preserves zero avgResponseTime", () => {
+    const metrics = { avgResponseTime: 0 };
+    const card = createMetricsCard("Tools", metrics);
+    expect(card.textContent).toContain("0.0 ms");
+  });
 });
 
 // ===================================================================

tests/unit/mcpgateway/utils/test_metrics_common.py

@@ -44,3 +44,20 @@ def test_build_top_performers_handles_missing_values():
     assert performers[0].avg_response_time is None
     assert performers[0].success_rate is None
     assert performers[0].last_execution is None
+
+
+def test_build_top_performers_preserves_zero_values():
+    """Zero avg_response_time and success_rate must not be coerced to None."""
+    result = SimpleNamespace(
+        id=3,
+        name="zero-tool",
+        execution_count=10,
+        avg_response_time=0.0,
+        success_rate=0.0,
+        last_execution=None,
+    )
+
+    performers = build_top_performers([result])
+
+    assert performers[0].avg_response_time == 0.0
+    assert performers[0].success_rate == 0.0