Primarily, it could be caused by a corrupt disk - which is why checking if it's happening on a specific node(s) can help.
Arun On Aug 16, 2012, at 10:04 AM, Pavan Kulkarni wrote: > Harsh, > > I see this on couple of nodes.But what may be the cause of this error ?Any > idea about it? Thanks > > On Sun, Aug 12, 2012 at 9:06 AM, Harsh J <ha...@cloudera.com> wrote: > >> Hi Pavan, >> >> Do you see this happen on a specific node every time (i.e. when the >> reducer runs there)? >> >> On Fri, Aug 10, 2012 at 11:43 PM, Pavan Kulkarni >> <pavan.babu...@gmail.com> wrote: >>> Hi, >>> >>> I am running a Terasort with a cluster of 8 nodes.The map phase >> completes >>> but when the reduce phase is around 68-70% I get this following error. >>> >>> * >>> 12/08/10 11:02:36 INFO mapred.JobClient: Task Id : >>> attempt_201208101018_0001_r_000027_0, Status : FAILED >>> java.lang.RuntimeException: problem advancing post rec#38320220 >>> * >>> * at >>> org.apache.hadoop.mapred.Task$ValuesIterator.next(Task.java:1214)* >>> * at >>> >> org.apache.hadoop.mapred.ReduceTask$ReduceValuesIterator.moveToNext(ReduceTask.java:249) >>> * >>> * at >>> >> org.apache.hadoop.mapred.ReduceTask$ReduceValuesIterator.next(ReduceTask.java:245) >>> * >>> * at >>> >> org.apache.hadoop.mapred.lib.IdentityReducer.reduce(IdentityReducer.java:40) >>> * >>> * at >>> org.apache.hadoop.mapred.ReduceTask.runOldReducer(ReduceTask.java:519)* >>> * at org.apache.hadoop.mapred.ReduceTask.run(ReduceTask.java:420)* >>> * at org.apache.hadoop.mapred.Child$4.run(Child.java:255)* >>> * at java.security.AccessController.doPrivileged(Native Method)* >>> * at javax.security.auth.Subject.doAs(Subject.java:416)* >>> * at >>> >> org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1093) >>> * >>> * at org.apache.hadoop.mapred.Child.main(Child.java:249)* >>> *Caused by: org.apache.hadoop.fs.ChecksumException: Checksum Error* >>> * at >>> >> org.apache.hadoop.mapred.IFileInputStream.doRead(IFileInputStream.java:164)* >>> * at >>> >> org.apache.hadoop.mapred.IFileInputStream.read(IFileInputStream.java:101)* >>> * at >> org.apache.hadoop.mapred.IFile$Reader.readData(IFile.java:328)* >>> * at >> org.apache.hadoop.mapred.IFile$Reader.rejigData(IFile.java:358)* >>> * at >>> org.apache.hadoop.mapred.IFile$Reader.readNextBlock(IFile.java:342)* >>> * at org.apache.hadoop.mapred.IFile$Reader.next(IFile.java:374)* >>> * at >> org.apache.hadoop.mapred.Merger$Segment.next(Merger.java:220)* >>> * at >>> >> org.apache.hadoop.mapred.Merger$MergeQueue.adjustPriorityQueue(Merger.java:330) >>> * >>> * at >> org.apache.hadoop.mapred.Merger$MergeQueue.next(Merger.java:350) >>> * >>> * at >>> >> org.apache.hadoop.mapred.ReduceTask$ReduceCopier$RawKVIteratorReader.next(ReduceTask.java:2531) >>> * >>> * at >> org.apache.hadoop.mapred.Merger$Segment.next(Merger.java:220)* >>> * at >>> >> org.apache.hadoop.mapred.Merger$MergeQueue.adjustPriorityQueue(Merger.java:330) >>> * >>> * at >> org.apache.hadoop.mapred.Merger$MergeQueue.next(Merger.java:350) >>> * >>> * at >>> org.apache.hadoop.mapred.Task$ValuesIterator.readNextKey(Task.java:1253)* >>> * at >>> org.apache.hadoop.mapred.Task$ValuesIterator.next(Task.java:1212)* >>> * ... 10 more* >>> >>> I came across somone facing the same >>> issue< >> http://mail-archives.apache.org/mod_mbox/hadoop-common-user/201001.mbox/%3c1c802db51001280427j5b8e57dai4a8d0fdd038...@mail.gmail.com%3E >>> in >>> the mail-archives and he seemed to resolve it by listing hostnames in >>> the */etc/hosts *file, >>> but all my nodes have correct info about the hostnames in /etc/hosts, >> but I >>> still have these reducers throwing error. >>> Any help regarding this issue is appreciated .Thanks >>> >>> -- >>> >>> --With Regards >>> Pavan Kulkarni >> >> >> >> -- >> Harsh J >> > > > > -- > > --With Regards > Pavan Kulkarni -- Arun C. Murthy Hortonworks Inc. http://hortonworks.com/
