diff --git a/hbase-rsgroup/src/main/java/org/apache/hadoop/hbase/rsgroup/RSGroupInfoManagerImpl.java b/hbase-rsgroup/src/main/java/org/apache/hadoop/hbase/rsgroup/RSGroupInfoManagerImpl.java
index eec03ce80a5..80eaefb036c 100644
--- a/hbase-rsgroup/src/main/java/org/apache/hadoop/hbase/rsgroup/RSGroupInfoManagerImpl.java
+++ b/hbase-rsgroup/src/main/java/org/apache/hadoop/hbase/rsgroup/RSGroupInfoManagerImpl.java
@@ -640,7 +640,9 @@ public class RSGroupInfoManagerImpl implements RSGroupInfoManager, ServerListene
                     if(cell != null) {
                       sn = ServerName.parseVersionedServerName(CellUtil.cloneValue(cell));
                     }
-                    if (tsm.isTableState(TableName.NAMESPACE_TABLE_NAME,
+                    if (sn == null) {
+                      nsFound.set(false);
+                    } else if (tsm.isTableState(TableName.NAMESPACE_TABLE_NAME,
                         ZooKeeperProtos.Table.State.ENABLED)) {
                       try {
                         ClientProtos.ClientService.BlockingInterface rs = conn.getClient(sn);