我目前正在使用Hadoop 0.21.0、985326和由6个工作节点和一个头节点组成的集群的项目中工作。提交常规mapreduce作业失败，但是我不知道为什么。有人见过这种例外吗？
org.apache.hadoop.mapred.Child: Exception running child : java.io.IOException: Spill failed
at org.apache.hadoop.mapred.MapTask$MapOutputBuffer.checkSpillException(MapTask.java:1379)
at org.apache.hadoop.mapred.MapTask$MapOutputBuffer.access$200(MapTask.java:711)
at org.apache.hadoop.mapred.MapTask$MapOutputBuffer$Buffer.write(MapTask.java:1193)
at java.io.DataOutputStream.write(DataOutputStream.java:90)
at org.apache.hadoop.io.Text.write(Text.java:290)
at org.apache.hadoop.io.serializer.WritableSerialization$WritableSerializer.serialize(WritableSerialization.java:100)
at org.apache.hadoop.io.serializer.WritableSerialization$WritableSerializer.serialize(WritableSerialization.java:84)
at org.apache.hadoop.mapred.MapTask$MapOutputBuffer.collect(MapTask.java:967)
at org.apache.hadoop.mapred.MapTask$NewOutputCollector.write(MapTask.java:583)
at org.apache.hadoop.mapreduce.task.TaskInputOutputContextImpl.write(TaskInputOutputContextImpl.java:92)
at org.apache.hadoop.mapreduce.lib.map.WrappedMapper$Context.write(WrappedMapper.java:111)
at be.ac.ua.comp.ronny.riki.invertedindex.FilteredInvertedIndexBuilder$Map.map(FilteredInvertedIndexBuilder.java:113)
at be.ac.ua.comp.ronny.riki.invertedindex.FilteredInvertedIndexBuilder$Map.map(FilteredInvertedIndexBuilder.java:1)
at org.apache.hadoop.mapreduce.Mapper.run(Mapper.java:144)
at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:652)
at org.apache.hadoop.mapred.MapTask.run(MapTask.java:328)
at org.apache.hadoop.mapred.Child$4.run(Child.java:217)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:396)
at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:742)
at org.apache.hadoop.mapred.Child.main(Child.java:211)
Caused by: java.lang.RuntimeException: java.lang.NoSuchMethodException: org.apache.hadoop.io.ArrayWritable.<init>()
at org.apache.hadoop.util.ReflectionUtils.newInstance(ReflectionUtils.java:123)
at org.apache.hadoop.io.serializer.WritableSerialization$WritableDeserializer.deserialize(WritableSerialization.java:68)
at org.apache.hadoop.io.serializer.WritableSerialization$WritableDeserializer.deserialize(WritableSerialization.java:44)
at org.apache.hadoop.mapreduce.task.ReduceContextImpl.nextKeyValue(ReduceContextImpl.java:145)
at org.apache.hadoop.mapreduce.task.ReduceContextImpl.nextKey(ReduceContextImpl.java:121)
at org.apache.hadoop.mapreduce.lib.reduce.WrappedReducer$Context.nextKey(WrappedReducer.java:291)
at org.apache.hadoop.mapreduce.Reducer.run(Reducer.java:168)
at org.apache.hadoop.mapred.Task$NewCombinerRunner.combine(Task.java:1432)
at org.apache.hadoop.mapred.MapTask$MapOutputBuffer.sortAndSpill(MapTask.java:1457)
at org.apache.hadoop.mapred.MapTask$MapOutputBuffer.access$600(MapTask.java:711)
at org.apache.hadoop.mapred.MapTask$MapOutputBuffer$SpillThread.run(MapTask.java:1349) …