Hi, I am not sure if this question (as title) has been asked before, but I didn't find an answer by googling.
I'd like to explain the scenario of my problem: My program launches several threads in the same time, while each thread will submit a hadoop job and wait for the job to complete. The unit tests were run in local mode, mini-cluster and the real hadoop cluster. I found the unit tests may fail in local mode, but they always succeeded in mini-cluster and real hadoop cluster. When unit test failed in local mode, the causes may be different (stack traces are posted at the end of mail). It seems multi-thead running multiple jobs is not supported in local mode, is it? Error 1: 2011-07-01 20:24:36,460 WARN [Thread-38] mapred.LocalJobRunner (LocalJobRunner.java:run(256)) - job_local_0001 java.io.FileNotFoundException: File build/test/tmp/mapred/local/taskTracker/jobcache/job_local_0001/attempt_local_0001_m_000000_0/output/spill0.out does not exist. at org.apache.hadoop.fs.RawLocalFileSystem.getFileStatus(RawLocalFileSystem.java:361) at org.apache.hadoop.fs.FileUtil.copy(FileUtil.java:192) at org.apache.hadoop.fs.FileUtil.copy(FileUtil.java:142) at org.apache.hadoop.fs.RawLocalFileSystem.rename(RawLocalFileSystem.java:253) at org.apache.hadoop.mapred.MapTask$MapOutputBuffer.mergeParts(MapTask.java:1447) at org.apache.hadoop.mapred.MapTask$MapOutputBuffer.flush(MapTask.java:1154) at org.apache.hadoop.mapred.MapTask$NewOutputCollector.close(MapTask.java:549) at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:623) at org.apache.hadoop.mapred.MapTask.run(MapTask.java:305) at org.apache.hadoop.mapred.LocalJobRunner$Job.run(LocalJobRunner.java:177) Error 2: 2011-07-01 19:00:25,546 INFO [Thread-32] fs.FSInputChecker (FSInputChecker.java:readChecksumChunk(247)) - Found checksum error: b[3584, 4096]=696f6e69643c2f6e616d653e3c76616c75653e47302e4120636f696e636964656e63652047312e413c2f76616c75653e3c2f70726f70657274793e0a3c70726f70657274793e3c6e616d653e6d61707265642e6a6f622e747261636b65722e706572736973742e6a6f627374617475732e6469723c2f6e616d653e3c76616c75653e2f6a6f62747261636b65722f6a6f6273496e666f3c2f76616c75653e3c2f70726f70657274793e0a3c70726f70657274793e3c6e616d653e6d61707265642e6a61723c2f6e616d653e3c76616c75653e66696c653a2f686f6d652f70616e797a682f6861646f6f7063616c632f6275696c642f746573742f746d702f6d61707265642f73797374656d2f6a6f625f6c6f63616c5f303030332f6a6f622e6a61723c2f76616c75653e3c2f70726f70657274793e0a3c70726f70657274793e3c6e616d653e66732e73332e6275666665722e6469723c2f6e616d653e3c76616c75653e247b6861646f6f702e746d702e6469727d2f73333c2f76616c75653e3c2f70726f70657274793e0a3c70726f70657274793e3c6e616d653e6a6f622e656e642e72657472792e617474656d7074733c2f6e616d653e3c76616c75653e303c2f76616c75653e3c2f70726f70657274793e0a3c70726f70657274793e3c6e616d653e66732e66696c652e696d706c3c2f6e616d653e3c76616c75653e6f org.apache.hadoop.fs.ChecksumException: Checksum error: file:/home/hadoop-user/hadoop-proj/build/test/tmp/mapred/system/job_local_0003/job.xml at 3584 at org.apache.hadoop.fs.FSInputChecker.verifySum(FSInputChecker.java:277) at org.apache.hadoop.fs.FSInputChecker.readChecksumChunk(FSInputChecker.java:241) at org.apache.hadoop.fs.FSInputChecker.read1(FSInputChecker.java:189) at org.apache.hadoop.fs.FSInputChecker.read(FSInputChecker.java:158) at java.io.DataInputStream.read(DataInputStream.java:83) at org.apache.hadoop.io.IOUtils.copyBytes(IOUtils.java:49) at org.apache.hadoop.io.IOUtils.copyBytes(IOUtils.java:87) at org.apache.hadoop.fs.FileUtil.copy(FileUtil.java:209) at org.apache.hadoop.fs.FileUtil.copy(FileUtil.java:142) at org.apache.hadoop.fs.LocalFileSystem.copyToLocalFile(LocalFileSystem.java:61) at org.apache.hadoop.fs.FileSystem.copyToLocalFile(FileSystem.java:1197) at org.apache.hadoop.mapred.LocalJobRunner$Job.<init>(LocalJobRunner.java:92) at org.apache.hadoop.mapred.LocalJobRunner.submitJob(LocalJobRunner.java:373) at org.apache.hadoop.mapred.JobClient.submitJobInternal(JobClient.java:800) at org.apache.hadoop.mapreduce.Job.submit(Job.java:432) at org.apache.hadoop.mapreduce.Job.waitForCompletion(Job.java:448) at hadoop.GroupingRunnable.run(GroupingRunnable.java:126) at java.lang.Thread.run(Thread.java:619)
