Index: hbase-server/src/main/java/org/apache/hadoop/hbase/zookeeper/lock/ZKInterProcessLockBase.java =================================================================== --- hbase-server/src/main/java/org/apache/hadoop/hbase/zookeeper/lock/ZKInterProcessLockBase.java (revision 1484622) +++ hbase-server/src/main/java/org/apache/hadoop/hbase/zookeeper/lock/ZKInterProcessLockBase.java (working copy) @@ -423,7 +423,7 @@ LOG.error("Unexpected ZooKeeper error when listing children", e); throw new IOException("Unexpected ZooKeeper exception", e); } - if (children.size() > 0) { + if (children != null && children.size() > 0) { for (String child : children) { if (isChildOfSameType(child)) { String znode = ZKUtil.joinZNode(parentLockNode, child);