Reported here: https://issues.apache.org/jira/browse/HBASE-2015
Sadly, HBase codebase is too large and complex, so I cannot pretend to provide any patch. Running the setupIOstreams method in a doPrivileged block is a begin. http://svn.apache.org/viewvc/hadoop/hbase/trunk/src/java/org/apache/hadoop/hbase/ipc/HBaseClient.java?revision=826569&view=markup
