On Tue, Jan 09, 2007 at 12:36:10PM -0700, Andrew McNabb wrote: > > java.lang.NullPointerException > at > org.apache.hadoop.streaming.PipeMapRed.waitOutputThreads(PipeMapRed.java:455) > at > org.apache.hadoop.streaming.PipeMapRed.mapRedFinished(PipeMapRed.java:578) > at org.apache.hadoop.streaming.PipeMapper.close(PipeMapper.java:109) > at org.apache.hadoop.mapred.MapRunner.run(MapRunner.java:51) > at org.apache.hadoop.mapred.MapTask.run(MapTask.java:183) > at > org.apache.hadoop.mapred.TaskTracker$Child.main(TaskTracker.java:1341) >
Even when I fixed the bug in my mapper, it still gives this error. I can't see anything else in the logs. I went in and looked at the code. Line 455 of PipeMapRed.java is: sim.waitFor(); The Java documentation doesn't say anything about waitFor throwing a NullPointerException, and I don't see anything about how sim (a Process object) would get set to null. Sim is set at line 301: sim = Runtime.getRuntime().exec(argvSplit, childEnv.toArray()); The Java documentation doesn't say that exec can return null. I guess I'm confused about what's causing this exception to be thrown. Does anyone have any ideas? Thanks. -- Andrew McNabb http://www.mcnabbs.org/andrew/ PGP Fingerprint: 8A17 B57C 6879 1863 DE55 8012 AB4D 6098 8826 6868
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