feat: add adaptive metrics and circuit breaker trips tracking

Added metrics tracking for:
- circuit_breaker_trips_total: Incremented when circuit opens
- adaptive_health_status: 1 if healthy (not in aggressive mode), 0 otherwise
- adaptive_event_rate: Current events per second

Added methods to AdaptiveTimeoutCalculator:
- getEventRate(): Returns current event rate in events/second
- isHealthy(): Returns true if not in aggressive mode

Metrics are updated on each buffer flush when adaptive timeout is enabled.

src/Utils/circuit-breaker.ts

@@ -380,6 +380,11 @@ export class CircuitBreaker extends EventEmitter {
 				this.options.onOpen()
 				this.emit('open')
 
+				// Record circuit breaker trip metric
+				if (this.options.collectMetrics) {
+					metrics.circuitBreakerTrips?.inc({ name: this.options.name })
+				}
+
 				// Schedule transition to HALF_OPEN
 				this.resetTimer = setTimeout(() => {
 					this.transitionTo('half-open')

src/Utils/event-buffer.ts

@@ -329,6 +329,31 @@ class AdaptiveTimeoutCalculator {
 		}
 		return 'balanced'
 	}
+
+	/**
+	 * Get current event rate in events per second
+	 */
+	getEventRate(): number {
+		if (this.eventTimestamps.length < 2) {
+			return 0
+		}
+		const oldest = this.eventTimestamps[0]!
+		const newest = this.eventTimestamps[this.eventTimestamps.length - 1]!
+		const timeSpan = newest - oldest
+		if (timeSpan === 0) return 0
+		return (this.eventTimestamps.length / timeSpan) * 1000
+	}
+
+	/**
+	 * Check if system is healthy based on current mode
+	 * Conservative mode with low event rate is healthy
+	 * Aggressive mode might indicate high load
+	 */
+	isHealthy(): boolean {
+		const mode = this.getMode()
+		// System is considered healthy if not in aggressive mode (high load)
+		return mode !== 'aggressive'
+	}
 }
 
 // ============================================================================
@@ -563,6 +588,11 @@ export const makeEventBuffer = (
 		// Record metrics
 		recordFlushMetrics(eventCount, force, historyCache.size)
 
+		// Update adaptive metrics
+		if (config.enableAdaptiveTimeout && metricsModule) {
+			metricsModule.updateAdaptiveMetrics(adaptiveTimeout.getEventRate(), adaptiveTimeout.isHealthy())
+		}
+
 		// Log with [BAILEYS] prefix - use getMode() to avoid duplicating mode calculation logic
 		const flushDuration = Date.now() - flushStartTime
 		logEventBuffer('buffer_flush', {

src/Utils/prometheus-metrics.ts

@@ -1958,6 +1958,19 @@ export function recordBufferFinalFlush(): void {
 	}
 }
 
+/**
+ * Update adaptive system metrics
+ * Used by event-buffer.ts to report adaptive timeout health and event rate
+ */
+export function updateAdaptiveMetrics(eventRate: number, isHealthy: boolean): void {
+	try {
+		metrics.adaptiveEventRate?.set({}, eventRate)
+		metrics.adaptiveHealthStatus?.set({}, isHealthy ? 1 : 0)
+	} catch {
+		// Metrics not initialized, ignore silently
+	}
+}
+
 // ============================================
 // Global Instance
 // ============================================