feat: add events_errors_total metric (#18610)

cmd/metrics-v2.go

@@ -2475,6 +2475,16 @@ func getNotificationMetrics() *MetricsGroup {
 				},
 				Value: float64(nstats.EventsSkipped),
 			})
+			metrics = append(metrics, Metric{
+				Description: MetricDescription{
+					Namespace: minioNamespace,
+					Subsystem: notifySubsystem,
+					Name:      "events_errors_total",
+					Help:      "Events that were failed while sending to target",
+					Type:      counterMetric,
+				},
+				Value: float64(nstats.EventsErrorsTotal),
+			})
 			metrics = append(metrics, Metric{
 				Description: MetricDescription{
 					Namespace: minioNamespace,