The BtJob's BtMapper has some "interesting" logic in its setup routine, where
it looks like it's creating a side-channel:
/*
* actually this is kind of dangerous because this routine thinks we need
* to create file name for our current job and this will use -m- so it's
* just serendipity we are calling it from the mapper too as the QJob did.
*/
Path qInputPath =
new Path(qJobPath, FileOutputFormat.getUniqueFile(context,
QJob.OUTPUT_QHAT,
""));
blockNum = context.getTaskAttemptID().getTaskID().getId();
SequenceFileValueIterator<DenseBlockWritable> qhatInput =
new SequenceFileValueIterator<DenseBlockWritable>(qInputPath,
true,
conf);
closeables.addFirst(qhatInput);
It wouldn't surprise me if this fails when speculative execution is turned on.
-- Ken
> From: Dmitriy Lyubimov
> Sent: October 9, 2014 11:31:42am PDT
> To: [email protected]
> Subject: Re: SSVD: lease conflict due to 2 attempts using the same dir
>
> wow. good to know. however, it would seem to me like a bug in
> MultipleOutputs? either way, it doesn't seem anything to do with the Mahout
> code itself.
>
> On Thu, Oct 9, 2014 at 10:32 AM, Yang <[email protected]> wrote:
>
>> yes, that's what I'm saying, I disabled speculative, it works for now (kind
>> of is a hack)
>>
>>
>> also yes, this is hadoop 2.0 with YARN
>>
>> this has nothing to do with overwrite mode. the 2 attempts are run
>> simultaneously because they are speculative runs
>>
>> On Wed, Oct 8, 2014 at 12:07 AM, Serega Sheypak <[email protected]>
>> wrote:
>>
>>> owned by
>>> DFSClient_attempt_1412632629877_7081_*m_000000_1_**196610264_1
>>> *but is
>>> accessed by
>>> DFSClient_attempt_1412632629877_7081_*m_000000_0_**1051299648_1*
>>> at
>>>
>>> Looks like two clients try to write to the same dir and they are trying
>> to
>>> write to the same file.
>>>
>>> 2014-10-08 6:24 GMT+04:00 Dmitriy Lyubimov <[email protected]>:
>>>
>>>> Usually map reduce output format would issue a much clearer
>> message.this
>>> on
>>>> the other hand looks like a name node operation conflict.
>>>>
>>>> Sent from my phone.
>>>> On Oct 7, 2014 3:23 PM, "Suneel Marthi" <[email protected]> wrote:
>>>>
>>>>> Have u tried running with -ow (overwrite) option, that should clear
>> all
>>>>> tmpdir between successive runs ??
>>>>>
>>>>> The SSVD code does clear the tmpdir when -ow is specified.
>>>>>
>>>>> On Tue, Oct 7, 2014 at 5:55 PM, Yang <[email protected]> wrote:
>>>>>
>>>>>> we are running mahout ssvd, with a --tempDir parameter,
>>>>>> but we are constantly getting this error below.
>>>>>>
>>>>>> the following seems to suggest that the 2 attempts in mapper are
>>> trying
>>>>> to
>>>>>> access the same tmp dir on hdfs.
>>>>>>
>>>>>> if this is the cause, then ssvd has a bug in that different
>> attempts
>>>>> should
>>>>>> use different temp dirs . right?
>>>>>>
>>>>>>
>>>>>> I'm trying now without the --tempDir param
>>>>>>
>>>>>> thanks
>>>>>> Yang
>>>>>>
>>>>>> Error:
>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>> org.apache.hadoop.ipc.RemoteException(org.apache.hadoop.hdfs.server.namenode.LeaseExpiredException):
>>>>>> Lease mismatch on
>>>>> /user/myuser/CIReco/shoes/ssvd/tmp/ssvd/Bt-job/Q-m-00000
>>>>>> owned by
>> DFSClient_attempt_1412632629877_7081_m_000000_1_196610264_1
>>>> but
>>>>> is
>>>>>> accessed by
>>>> DFSClient_attempt_1412632629877_7081_m_000000_0_1051299648_1
>>>>> at
>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>> org.apache.hadoop.hdfs.server.namenode.FSNamesystem.checkLease(FSNamesystem.java:2967)
>>>>>> at
>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>> org.apache.hadoop.hdfs.server.namenode.FSNamesystem.completeFileInternal(FSNamesystem.java:3016)
>>>>>> at
>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>> org.apache.hadoop.hdfs.server.namenode.FSNamesystem.completeFile(FSNamesystem.java:2996)
>>>>>> at
>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>> org.apache.hadoop.hdfs.server.namenode.NameNodeRpcServer.complete(NameNodeRpcServer.java:647)
>>>>>> at
>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>> org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolServerSideTranslatorPB.complete(ClientNamenodeProtocolServerSideTranslatorPB.java:484)
>>>>>> at
>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>> org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos$ClientNamenodeProtocol$2.callBlockingMethod(ClientNamenodeProtocolProtos.java)
>>>>>> at
>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>> org.apache.hadoop.ipc.ProtobufRpcEngine$Server$ProtoBufRpcInvoker.call(ProtobufRpcEngine.java:585)
>>>>>> at org.apache.hadoop.ipc.RPC$Server.call(RPC.java:928) at
>>>>>> org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:2020) at
>>>>>> org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:2016) at
>>>>>>
>>>>>> java.security.AccessController.doPrivileged(Native Method) at
>>>>>> javax.security.auth.Subject.doAs(Subject.java:415) at
>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>> org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1650)
>>>>>> at org.apache.hadoop.ipc.Server$Handler.run(Server.java:2014) at
>>>>>> org.apache.hadoop.ipc.Client.call(Client.java:1410) at
>>>>>> org.apache.hadoop.ipc.Client.call(Client.java:1363) at
>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>> org.apache.hadoop.ipc.ProtobufRpcEngine$Invoker.invoke(ProtobufRpcEngine.java:206)
>>>>>> at com.sun.proxy.$Proxy15.complete(Unknown Source) at
>>>>>> sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at
>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>> sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
>>>>>> at
>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
>>>>>> at java.lang.reflect.Method.invoke(Method.java:606) at
>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>> org.apache.hadoop.io.retry.RetryInvocationHandler.invokeMethod(RetryInvocationHandler.java:190)
>>>>>> at
>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>> org.apache.hadoop.io.retry.RetryInvocationHandler.invoke(RetryInvocationHandler.java:103)
>>>>>> at com.sun.proxy.$Proxy15.complete(Unknown Source) at
>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>> org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolTranslatorPB.complete(ClientNamenodeProtocolTranslatorPB.java:404)
>>>>>> at
>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>> org.apache.hadoop.hdfs.DFSOutputStream.completeFile(DFSOutputStream.java:2116)
>>>>>> at
>>>>>
>> org.apache.hadoop.hdfs.DFSOutputStream.close(DFSOutputStream.java:2100)
>>>>>> at
>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>> org.apache.hadoop.fs.FSDataOutputStream$PositionCache.close(FSDataOutputStream.java:70)
>>>>>> at
>>>>>>
>>>>>
>>>>
>>>
>> org.apache.hadoop.fs.FSDataOutputStream.close(FSDataOutputStream.java:103)
>>>>>> at
>>>> org.apache.hadoop.io.SequenceFile$Writer.close(SequenceFile.java:1279)
>>>>>> at
>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>> org.apache.hadoop.io.SequenceFile$BlockCompressWriter.close(SequenceFile.java:1501)
>>>>>> at
>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>> org.apache.hadoop.mapred.SequenceFileOutputFormat$1.close(SequenceFileOutputFormat.java:79)
>>>>>> at
>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>> org.apache.hadoop.mapred.lib.MultipleOutputs.close(MultipleOutputs.java:537)
>>>>>> at
>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>> org.apache.mahout.common.IOUtils$MultipleOutputsCloseableAdapter.close(IOUtils.java:193)
>>>>>> at org.apache.mahout.common.IOUtils.close(IOUtils.java:128) at
>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>> org.apache.mahout.math.hadoop.stochasticsvd.BtJob$BtMapper.cleanup(BtJob.java:295)
>>>>>> at org.apache.hadoop.mapreduce.Mapper.run(Mapper.java:148) at
>>>>>> org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:764) at
>>>>>> org.apache.hadoop.mapred.MapTask.run(MapTask.java:340) at
>>>>>> org.apache.hadoop.mapred.YarnChild$2.run(YarnChild.java:167) at
>>>>>> java.security.AccessController.doPrivileged(Native Method) at
>>>>>> javax.security.auth.Subject.doAs(Subject.java:415) at
>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>> org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1650)
>>>>>> at org.apache.hadoop.mapred.YarnChild.main(YarnChild.java:162)
>>>>>>
>>>>>
>>>>
>>>
>>
--------------------------
Ken Krugler
+1 530-210-6378
http://www.scaleunlimited.com
custom big data solutions & training
Hadoop, Cascading, Cassandra & Solr
--------------------------
Ken Krugler
+1 530-210-6378
http://www.scaleunlimited.com
custom big data solutions & training
Hadoop, Cascading, Cassandra & Solr
