Index: src/main/java/org/apache/hadoop/hbase/master/AssignmentManager.java =================================================================== --- src/main/java/org/apache/hadoop/hbase/master/AssignmentManager.java (revision 1124468) +++ src/main/java/org/apache/hadoop/hbase/master/AssignmentManager.java (working copy) @@ -1995,7 +1995,9 @@ for (Iterator > i = this.regionPlans.entrySet().iterator(); i.hasNext();) { Map.Entry e = i.next(); - if (e.getValue().getDestination().equals(sn)) { + ServerName otherSn = e.getValue().getDestination(); + // The name will be null if the region is planned for a random assign. + if (otherSn != null && otherSn.equals(sn)) { // Use iterator's remove else we'll get CME i.remove(); }