HBASE-24683 Add a basic ReplicationServer which only implement ReplicationSink Service

Author: ddupg

hbase-common/src/main/java/org/apache/hadoop/hbase/util/DNS.java

@@ -54,7 +54,8 @@ public final class DNS {
 
   public enum ServerType {
     MASTER("master"),
-    REGIONSERVER("regionserver");
+    REGIONSERVER("regionserver"),
+    REPLICATIONSERVER("replicationserver");
 
     private String name;
     ServerType(String name) {