java.lang.NullPointerException
at org.apache.hadoop.hdfs.server.datanode.DataNode.requestShortCircuitFdsForRead(DataNode.java:1525)
at org.apache.hadoop.hdfs.server.datanode.DataXceiver.requestShortCircuitFds(DataXceiver.java:286)
at org.apache.hadoop.hdfs.protocol.datatransfer.Receiver.opRequestShortCircuitFds(Receiver.java:185)
at org.apache.hadoop.hdfs.protocol.datatransfer.Receiver.processOp(Receiver.java:89)
at org.apache.hadoop.hdfs.server.datanode.DataXceiver.run(DataXceiver.java:234)
at java.lang.Thread.run(Thread.java:745)