fix(alerting): remove possible divide by zero panic

bergquist · bergquist · commit 3ea66ebe3fb7 · 2016-11-17T15:20:14.000+01:00
ref grafana#6599
diff --git a/pkg/services/alerting/scheduler.go b/pkg/services/alerting/scheduler.go
@@ -39,6 +39,9 @@ func (s *SchedulerImpl) Update(rules []*Rule) {
 
 		offset := ((rule.Frequency * 1000) / int64(len(rules))) * int64(i)
 		job.Offset = int64(math.Floor(float64(offset) / 1000))
+		if job.Offset == 0 { //zero offset causes division with 0 panics.
+			job.Offset = 1
+		}
 		jobs[rule.Id] = job
 	}
 

Original file line number	Diff line number	Diff line change
`@@ -39,6 +39,9 @@ func (s SchedulerImpl) Update(rules []Rule) {`
`39`	`39`
`40`	`40`	`offset := ((rule.Frequency * 1000) / int64(len(rules))) * int64(i)`
`41`	`41`	`job.Offset = int64(math.Floor(float64(offset) / 1000))`
	`42`	`+ if job.Offset == 0 { //zero offset causes division with 0 panics.`
	`43`	`+ job.Offset = 1`
	`44`	`+ }`
`42`	`45`	`jobs[rule.Id] = job`
`43`	`46`	`}`
`44`	`47`