revert dubbo version
diff --git a/dubbo-samples-grpc/dubbo-samples-reactor/pom.xml b/dubbo-samples-grpc/dubbo-samples-reactor/pom.xml
index e113971..0456d6e 100644
--- a/dubbo-samples-grpc/dubbo-samples-reactor/pom.xml
+++ b/dubbo-samples-grpc/dubbo-samples-reactor/pom.xml
@@ -28,7 +28,7 @@
     <properties>
         <source.level>1.8</source.level>
         <target.level>1.8</target.level>
-        <dubbo.version>3.0.0-20210226-SNAPSHOT</dubbo.version>
+        <dubbo.version>2.7.7</dubbo.version>
         <junit.version>4.12</junit.version>
         <spring.version>4.3.16.RELEASE</spring.version>
         <grpc.version>1.31.1</grpc.version>