From 14f10b47f67b05b829da324696c892a9e67811c4 Mon Sep 17 00:00:00 2001
From: zhaochun <zhaochun@baidu.com>
Date: Thu, 15 Nov 2018 19:56:13 +0800
Subject: [PATCH] Fix SHOW BACKENDS return ERROR

In some case, errMsg in Backend maybe null. we change it when check it
nut null

Issue: #317
---
 fe/src/main/java/org/apache/doris/system/Backend.java | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/fe/src/main/java/org/apache/doris/system/Backend.java b/fe/src/main/java/org/apache/doris/system/Backend.java
index a05121cf626e23..46b96dee830201 100644
--- a/fe/src/main/java/org/apache/doris/system/Backend.java
+++ b/fe/src/main/java/org/apache/doris/system/Backend.java
@@ -212,7 +212,11 @@ public void setBad(EventBus eventBus, String errMsg) {
         }
 
         eventBus.post(new BackendEvent(BackendEventType.BACKEND_DOWN, "missing heartbeat", Long.valueOf(id)));
-        heartbeatErrMsg = errMsg;
+        // In some case, errMsg is null when catched Exception have no message, which can make
+        // `SHOW BACKENDS` return ERROR. We check errMsg here to avoid.
+        if (errMsg != null) {
+            heartbeatErrMsg = errMsg;
+        }
     }
 
     public void setBackendState(BackendState state) {