Index: src/main/java/org/apache/hadoop/hbase/ServerName.java =================================================================== --- src/main/java/org/apache/hadoop/hbase/ServerName.java (revision 1175309) +++ src/main/java/org/apache/hadoop/hbase/ServerName.java (working copy) @@ -78,6 +78,10 @@ throw new IllegalArgumentException("Passed hostname is null or empty"); } int index = serverName.indexOf(SERVERNAME_SEPARATOR); + if (index < 0) { + throw new IllegalArgumentException("Hostname not recognized: " + + serverName); + } return serverName.substring(0, index); }