add metrics

crates/obs/src/metrics/cluster_notification.rs

@@ -0,0 +1,36 @@
+use crate::metrics::{new_counter_md, subsystems, MetricDescriptor, MetricName};
+
+/// 通知相关指标描述符
+lazy_static::lazy_static! {
+    pub static ref NOTIFICATION_CURRENT_SEND_IN_PROGRESS_MD: MetricDescriptor =
+        new_counter_md(
+            MetricName::NotificationCurrentSendInProgress,
+            "Number of concurrent async Send calls active to all targets",
+            &[],  // 无标签
+            subsystems::NOTIFICATION
+        );
+
+    pub static ref NOTIFICATION_EVENTS_ERRORS_TOTAL_MD: MetricDescriptor =
+        new_counter_md(
+            MetricName::NotificationEventsErrorsTotal,
+            "Events that were failed to be sent to the targets",
+            &[],  // 无标签
+            subsystems::NOTIFICATION
+        );
+
+    pub static ref NOTIFICATION_EVENTS_SENT_TOTAL_MD: MetricDescriptor =
+        new_counter_md(
+            MetricName::NotificationEventsSentTotal,
+            "Total number of events sent to the targets",
+            &[],  // 无标签
+            subsystems::NOTIFICATION
+        );
+
+    pub static ref NOTIFICATION_EVENTS_SKIPPED_TOTAL_MD: MetricDescriptor =
+        new_counter_md(
+            MetricName::NotificationEventsSkippedTotal,
+            "Events that were skipped to be sent to the targets due to the in-memory queue being full",
+            &[],  // 无标签
+            subsystems::NOTIFICATION
+        );
+}