I am getting the following exception when running my mapreduce job on the cluster. What could this be caused by?

org.apache.hadoop.ipc.RemoteException(org.apache.hadoop.hdfs.server.namenode.LeaseExpiredException): No lease on /user/certification/clean/_temporary/_attempt_201308102216_0008_m_000001_0/invalid-m-00001.avro: File does not exist. [Lease.  Holder: DFSClient_NONMAPREDUCE_-2115278520_1, pendingcreates: 2]
    at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.checkLease(FSNamesystem.java:2445)
    at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.analyzeFileState(FSNamesystem.java:2262)
    at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.getAdditionalBlock(FSNamesystem.java:2175)
    at org.apache.hadoop.hdfs.server.namenode.NameNodeRpcServer.addBlock(NameNodeRpcServer.java:480)
    at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolServerSideTranslatorPB.addBlock(ClientNamenodeProtocolServerSideTranslatorPB.java:299)
    at org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos$ClientNamenodeProtocol$2.callBlockingMethod(ClientNamenodeProtocolProtos.java:44954)
    at org.apache.hadoop.ipc.ProtobufRpcEngine$Server$ProtoBufRpcInvoker.call(ProtobufRpcEngine.java:453)
    at org.apache.hadoop.ipc.RPC$Server.call(RPC.java:1002)
    at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:1701)
    at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:1697)
    at java.security.AccessController.doPrivileged(Native Method)
    at javax.security.auth.Subject.doAs(Subject.java:396)
    at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1408)
    at org.apache.hadoop.ipc.Server$Handler.run(Server.java:1695)