Handle errors when checking for first match level

alert.go

@@ -591,7 +591,9 @@ func (a *AlertNode) handleAlert(ad *AlertData) {
 }
 
 func (a *AlertNode) determineLevel(now time.Time, fields models.Fields, tags map[string]string, currentLevel AlertLevel) AlertLevel {
-	if higherLevel, err := a.findFirstMatchLevel(CritAlert, currentLevel-1, now, fields, tags); err == nil {
+	if higherLevel, err := a.findFirstMatchLevel(CritAlert, currentLevel-1, now, fields, tags); err != nil {
+		a.logger.Printf("D! find first match level from %s to %s: %s", CritAlert, currentLevel-1, err)
+	} else {
 		return higherLevel
 	}
 	if rse := a.levelResets[currentLevel]; rse != nil {
@@ -601,7 +603,9 @@ func (a *AlertNode) determineLevel(now time.Time, fields models.Fields, tags map
 			return currentLevel
 		}
 	}
-	if newLevel, err := a.findFirstMatchLevel(currentLevel-1, OKAlert, now, fields, tags); err == nil {
+	if newLevel, err := a.findFirstMatchLevel(currentLevel, OKAlert, now, fields, tags); err != nil {
+		a.logger.Printf("D! find first match level from %s to %s: %s", currentLevel, OKAlert, err)
+	} else {
 		return newLevel
 	}
 	return OKAlert
@@ -623,7 +627,7 @@ func (a *AlertNode) findFirstMatchLevel(start AlertLevel, stop AlertLevel, now t
 			return AlertLevel(l), nil
 		}
 	}
-	return OKAlert, errors.New("No match found")
+	return OKAlert, errors.New("no match found")
 }
 
 func (a *AlertNode) batchToResult(b models.Batch) influxql.Result {