MM-57882 Add metric for the time it takes to open the Threads list (#26983)

* MM-57882 Add metric for the time it takes to open the Threads list

* Clean up mark because the starting mark may be missing

* Pass global threads load duration to Prometheus

* Update mocks

server/enterprise/metrics/metrics.go

@@ -211,15 +211,16 @@ type MetricsInterfaceImpl struct {
 	NotificationNotSentCounters     *prometheus.CounterVec
 	NotificationUnsupportedCounters *prometheus.CounterVec
 
-	ClientTimeToFirstByte        *prometheus.HistogramVec
-	ClientFirstContentfulPaint   *prometheus.HistogramVec
-	ClientLargestContentfulPaint *prometheus.HistogramVec
-	ClientInteractionToNextPaint *prometheus.HistogramVec
-	ClientCumulativeLayoutShift  *prometheus.HistogramVec
-	ClientLongTasks              *prometheus.CounterVec
-	ClientChannelSwitchDuration  *prometheus.HistogramVec
-	ClientTeamSwitchDuration     *prometheus.HistogramVec
-	ClientRHSLoadDuration        *prometheus.HistogramVec
+	ClientTimeToFirstByte           *prometheus.HistogramVec
+	ClientFirstContentfulPaint      *prometheus.HistogramVec
+	ClientLargestContentfulPaint    *prometheus.HistogramVec
+	ClientInteractionToNextPaint    *prometheus.HistogramVec
+	ClientCumulativeLayoutShift     *prometheus.HistogramVec
+	ClientLongTasks                 *prometheus.CounterVec
+	ClientChannelSwitchDuration     *prometheus.HistogramVec
+	ClientTeamSwitchDuration        *prometheus.HistogramVec
+	ClientRHSLoadDuration           *prometheus.HistogramVec
+	ClientGlobalThreadsLoadDuration *prometheus.HistogramVec
 }
 
 func init() {
@@ -1232,6 +1233,17 @@ func New(ps *platform.PlatformService, driver, dataSource string) *MetricsInterf
 	)
 	m.Registry.MustRegister(m.ClientRHSLoadDuration)
 
+	m.ClientGlobalThreadsLoadDuration = prometheus.NewHistogramVec(
+		prometheus.HistogramOpts{
+			Namespace: MetricsNamespace,
+			Subsystem: MetricsSubsystemClientsWeb,
+			Name:      "global_threads_load",
+			Help:      "Duration of the time taken from when a user clicks to open Threads in the LHS until when the global threads view becomes visible (milliseconds)",
+		},
+		[]string{"platform", "agent"},
+	)
+	m.Registry.MustRegister(m.ClientGlobalThreadsLoadDuration)
+
 	return m
 }
 
@@ -1726,6 +1738,10 @@ func (mi *MetricsInterfaceImpl) ObserveClientRHSLoadDuration(platform, agent str
 	mi.ClientRHSLoadDuration.With(prometheus.Labels{"platform": platform, "agent": agent}).Observe(elapsed)
 }
 
+func (mi *MetricsInterfaceImpl) ObserveGlobalThreadsLoadDuration(platform, agent string, elapsed float64) {
+	mi.ClientGlobalThreadsLoadDuration.With(prometheus.Labels{"platform": platform, "agent": agent}).Observe(elapsed)
+}
+
 func extractDBCluster(driver, connectionString string) (string, error) {
 	host, err := extractHost(driver, connectionString)
 	if err != nil {