more health check fixes, check slot rate

src/core/healthCheck.ts

@@ -13,7 +13,7 @@ const HEALTH_CHECK_CONFIG = {
 	CHECK_INTERVAL_MS: 2000,
 	// Maximum time allowed between slot updates
 	MAX_SLOT_STALENESS_MS: 5000,
-	// Minimum expected slot advancement rate (slots per second)
+	// Minimum expected slot advancement rate (slots slower than 1 per second is problematic)
 	MIN_SLOT_RATE: 1,
 } as const;
 
@@ -49,13 +49,27 @@ function evaluateHealth(currentSlot: number): {
 	const timeDelta = now - globalHealthState.lastSlotTimestamp;
 	const slotDelta = currentSlot - globalHealthState.lastSlot;
 
-	// Update state if slot has progressed
+	// If slot has progressed, we are healthy, check rate and update state.
 	if (currentSlot > globalHealthState.lastSlot) {
+		// Update state
 		globalHealthState.lastSlot = currentSlot;
 		globalHealthState.lastSlotTimestamp = now;
+
+		// Check if slot update rate is too low
+		const slotRate = (slotDelta / timeDelta) * 1000; // Convert to per second
+		if (slotRate < HEALTH_CHECK_CONFIG.MIN_SLOT_RATE) {
+			return {
+				isHealthy: false,
+				reason: `Slot update rate ${slotRate.toFixed(
+					2
+				)} slots/sec below minimum ${HEALTH_CHECK_CONFIG.MIN_SLOT_RATE}`,
+			};
+		}
+
+		return { isHealthy: true };
 	}
 
-	// Check if slots are too stale
+	// If slot has NOT progressed, check for staleness.
 	if (timeDelta > HEALTH_CHECK_CONFIG.MAX_SLOT_STALENESS_MS) {
 		return {
 			isHealthy: false,
@@ -63,17 +77,7 @@ function evaluateHealth(currentSlot: number): {
 		};
 	}
 
-	// Check if slot update rate is too low
-	const slotRate = (slotDelta / timeDelta) * 1000; // Convert to per second
-	if (slotRate < HEALTH_CHECK_CONFIG.MIN_SLOT_RATE) {
-		return {
-			isHealthy: false,
-			reason: `Slot update rate ${slotRate.toFixed(
-				2
-			)} slots/sec below minimum ${HEALTH_CHECK_CONFIG.MIN_SLOT_RATE}`,
-		};
-	}
-
+	// Slot has not progressed, but not stale yet. Still healthy.
 	return { isHealthy: true };
 }