feat: add system prune API v2 (#5395)

pkg/metrics/mem/server.go

@@ -95,9 +95,7 @@ func (m *serverMetrics) clearUselessInfo(continuousOfflineDuration time.Duration
 	defer m.mu.Unlock()
 	total = len(m.info.ProxyStatistics)
 	for name, data := range m.info.ProxyStatistics {
-		if !data.LastCloseTime.IsZero() &&
-			data.LastStartTime.Before(data.LastCloseTime) &&
-			m.clock.Since(data.LastCloseTime) > continuousOfflineDuration {
+		if m.shouldClearProxyStats(data, continuousOfflineDuration) {
 			delete(m.info.ProxyStatistics, name)
 			count++
 			log.Tracef("clear proxy [%s]'s statistics data, lastCloseTime: [%s]", name, data.LastCloseTime.String())
@@ -106,10 +104,20 @@ func (m *serverMetrics) clearUselessInfo(continuousOfflineDuration time.Duration
 	return count, total
 }
 
+func (m *serverMetrics) shouldClearProxyStats(data *ProxyStatistics, continuousOfflineDuration time.Duration) bool {
+	return !data.LastCloseTime.IsZero() &&
+		data.LastStartTime.Before(data.LastCloseTime) &&
+		m.clock.Since(data.LastCloseTime) > continuousOfflineDuration
+}
+
 func (m *serverMetrics) ClearOfflineProxies() (int, int) {
 	return m.clearUselessInfo(0)
 }
 
+func (m *serverMetrics) PruneOfflineProxies() (int, int) {
+	return m.clearUselessInfo(0)
+}
+
 func (m *serverMetrics) NewClient() {
 	m.info.ClientCounts.Inc(1)
 }

pkg/metrics/mem/server_test.go

@@ -43,6 +43,70 @@ func TestServerMetricsClearUselessInfoUsesClock(t *testing.T) {
 	require.Empty(metrics.info.ProxyStatistics)
 }
 
+func TestServerMetricsClearOfflineProxiesPreservesLegacyTotal(t *testing.T) {
+	require := require.New(t)
+
+	start := time.Date(2026, time.May, 8, 12, 30, 0, 0, time.UTC)
+	clk := clocktesting.NewFakeClock(start.Add(time.Minute))
+	metrics := newServerMetricsWithClock(clk)
+	metrics.info.ProxyStatistics["offline"] = &ProxyStatistics{
+		Name:          "offline",
+		LastStartTime: start.Add(-time.Hour),
+		LastCloseTime: start,
+	}
+	metrics.info.ProxyStatistics["online"] = &ProxyStatistics{
+		Name:          "online",
+		LastStartTime: start,
+	}
+
+	cleared, total := metrics.ClearOfflineProxies()
+
+	require.Equal(1, cleared)
+	require.Equal(2, total)
+	require.False(metrics.hasProxyStatistics("offline"))
+	require.True(metrics.hasProxyStatistics("online"))
+}
+
+func TestServerMetricsPruneOfflineProxiesReportsTotalStats(t *testing.T) {
+	require := require.New(t)
+
+	start := time.Date(2026, time.May, 8, 12, 30, 0, 0, time.UTC)
+	clk := clocktesting.NewFakeClock(start.Add(time.Minute))
+	metrics := newServerMetricsWithClock(clk)
+	metrics.info.ProxyStatistics["offline"] = &ProxyStatistics{
+		Name:          "offline",
+		LastStartTime: start.Add(-time.Hour),
+		LastCloseTime: start,
+	}
+	metrics.info.ProxyStatistics["online"] = &ProxyStatistics{
+		Name:          "online",
+		LastStartTime: start,
+	}
+	metrics.info.ProxyStatistics["restarted"] = &ProxyStatistics{
+		Name:          "restarted",
+		LastStartTime: start.Add(30 * time.Second),
+		LastCloseTime: start,
+	}
+	metrics.info.ProxyStatistics["same-time"] = &ProxyStatistics{
+		Name:          "same-time",
+		LastStartTime: start,
+		LastCloseTime: start,
+	}
+
+	cleared, total := metrics.PruneOfflineProxies()
+
+	require.Equal(1, cleared)
+	require.Equal(4, total)
+	require.False(metrics.hasProxyStatistics("offline"))
+	require.True(metrics.hasProxyStatistics("online"))
+	require.True(metrics.hasProxyStatistics("restarted"))
+	require.True(metrics.hasProxyStatistics("same-time"))
+
+	cleared, total = metrics.PruneOfflineProxies()
+	require.Equal(0, cleared)
+	require.Equal(3, total)
+}
+
 func TestServerMetricsRunUsesClockTicker(t *testing.T) {
 	require := require.New(t)
 

pkg/metrics/mem/types.go

@@ -85,4 +85,5 @@ type Collector interface {
 	GetProxyByName(proxyName string) *ProxyStats
 	GetProxyTraffic(name string) *ProxyTrafficInfo
 	ClearOfflineProxies() (int, int)
+	PruneOfflineProxies() (int, int)
 }