From c7dae338f053892ff0d50e94f4e4fb6d8b14bb5a Mon Sep 17 00:00:00 2001
From: peng-yongsheng <8082209@qq.com>
Date: Sun, 4 Mar 2018 11:35:07 +0800
Subject: [PATCH] Make the alarm trend rate value is 0 when application size
 equal to 0.

---
 .../skywalking/apm/collector/ui/service/AlarmService.java   | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/apm-collector/apm-collector-ui/collector-ui-jetty-provider/src/main/java/org/apache/skywalking/apm/collector/ui/service/AlarmService.java b/apm-collector/apm-collector-ui/collector-ui-jetty-provider/src/main/java/org/apache/skywalking/apm/collector/ui/service/AlarmService.java
index 62bd60bfa..0af55fa97 100644
--- a/apm-collector/apm-collector-ui/collector-ui-jetty-provider/src/main/java/org/apache/skywalking/apm/collector/ui/service/AlarmService.java
+++ b/apm-collector/apm-collector-ui/collector-ui-jetty-provider/src/main/java/org/apache/skywalking/apm/collector/ui/service/AlarmService.java
@@ -146,7 +146,11 @@ public class AlarmService {
 
         AlarmTrend alarmTrend = new AlarmTrend();
         durationPoints.forEach(durationPoint -> {
-            alarmTrend.getNumOfAlarmRate().add((trendsMap.getOrDefault(durationPoint.getPoint(), 0) * 10000) / (applications.size()));
+            if (applications.size() == 0) {
+                alarmTrend.getNumOfAlarmRate().add(0);
+            } else {
+                alarmTrend.getNumOfAlarmRate().add((trendsMap.getOrDefault(durationPoint.getPoint(), 0) * 10000) / (applications.size()));
+            }
         });
         return alarmTrend;
     }