|
|
-
Does hadoop local mode support running multiple jobs in different threads?
Yaozhen Pan 2011-07-01, 12:42
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]=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
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)
-
Re: Does hadoop local mode support running multiple jobs in different threads?
madhu phatak 2011-07-27, 11:00
We already tested the similar scenario where each thread runs
a separate Hadoop job. It works fine with local mode. But make sure that you
don't too many parallel jobs because local mode some time not able handle
all the jobs at a time.
On Fri, Jul 1, 2011 at 6:12 PM, Yaozhen Pan <[EMAIL PROTECTED]> wrote:
> 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]=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
> 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)
-
Re: Does hadoop local mode support running multiple jobs in different threads?
Bryan Keller 2011-08-19, 22:51
I don't believe the local job tracker can handle launching multiple jobs in different threads. I am running into the same problems you are, where one job steps on the temp directory of another.
On Jul 1, 2011, at 5:42 AM, Yaozhen Pan wrote:
> 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]=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
> 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)
-
Re: Does hadoop local mode support running multiple jobs in different threads?
Bryan Keller 2011-08-19, 23:28
I looked into this a bit more. It seems the LocalJobTracker by default uses a single local map reduce directory (named "localRunner") for all jobs. Thus two simultaneous jobs will step on each other.
You can work around this however. Set the "mapped.local.dir" property on each of the job's configuration to something unique, like a UUID. The LocalJobTracker will then use this instead of the default "localRunner" directory, and the jobs shouldn't step on each other.
On Jul 1, 2011, at 5:42 AM, Yaozhen Pan wrote:
> 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]=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
> 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)
-
Re: Does hadoop local mode support running multiple jobs in different threads?
Bryan Keller 2011-08-19, 23:31
Correction, the property is "mapred.local.dir". (Darn Lion autocorrect).
On Aug 19, 2011, at 4:28 PM, Bryan Keller wrote:
> I looked into this a bit more. It seems the LocalJobTracker by default uses a single local map reduce directory (named "localRunner") for all jobs. Thus two simultaneous jobs will step on each other.
>
> You can work around this however. Set the "mapped.local.dir" property on each of the job's configuration to something unique, like a UUID. The LocalJobTracker will then use this instead of the default "localRunner" directory, and the jobs shouldn't step on each other.
>
>
> On Jul 1, 2011, at 5:42 AM, Yaozhen Pan wrote:
>
>> 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)
-
Re: Does hadoop local mode support running multiple jobs in different threads?
Bryan Keller 2011-08-19, 23:38
Sorry one more correction, the class is named LocalJobRunner (not LocalJobTracker).
On Aug 19, 2011, at 4:28 PM, Bryan Keller wrote:
> I looked into this a bit more. It seems the LocalJobTracker by default uses a single local map reduce directory (named "localRunner") for all jobs. Thus two simultaneous jobs will step on each other.
>
> You can work around this however. Set the "mapped.local.dir" property on each of the job's configuration to something unique, like a UUID. The LocalJobTracker will then use this instead of the default "localRunner" directory, and the jobs shouldn't step on each other.
>
>
> On Jul 1, 2011, at 5:42 AM, Yaozhen Pan wrote:
>
>> 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]=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
>> 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)
|
|
