From b6f7dce8c75bd56611223d7cd0f085300abdacd0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E5=90=B4=E6=99=9F=20Wu=20Sheng?= <wu.sheng@foxmail.com>
Date: Wed, 4 Mar 2020 17:28:53 +0800
Subject: [PATCH] forward compatbility for DCS (#4442)

---
 .../server/configuration/grpc/GRPCConfigWatcherRegister.java    | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/oap-server/server-configuration/grpc-configuration-sync/src/main/java/org/apache/skywalking/oap/server/configuration/grpc/GRPCConfigWatcherRegister.java b/oap-server/server-configuration/grpc-configuration-sync/src/main/java/org/apache/skywalking/oap/server/configuration/grpc/GRPCConfigWatcherRegister.java
index 1332e0b7a..973545902 100644
--- a/oap-server/server-configuration/grpc-configuration-sync/src/main/java/org/apache/skywalking/oap/server/configuration/grpc/GRPCConfigWatcherRegister.java
+++ b/oap-server/server-configuration/grpc-configuration-sync/src/main/java/org/apache/skywalking/oap/server/configuration/grpc/GRPCConfigWatcherRegister.java
@@ -57,7 +57,7 @@ public class GRPCConfigWatcherRegister extends ConfigWatcherRegister {
             }
             ConfigurationResponse response = stub.call(builder.build());
             String responseUuid = response.getUuid();
-            if (Objects.equals(uuid, responseUuid)) {
+            if (responseUuid != null && Objects.equals(uuid, responseUuid)) {
                 // If UUID matched, the config table is expected as empty.
                 return Optional.empty();
             }