I am experiencing a similar problem (hadoop 0.14.1 on a 2-node pool
running java 1.5.0). Tried both grep and pi examples. Map tasks
completed 100%, reduce tasks hang at 16%:
INFO mapred.JobClient: map 100% reduce 16%
Job details view on http://localhost:50070jobdetails.jsp?jobid=... etc
shows no Failed/Killed Task Attempts.
A tail on the tasktracker log keeps reiterating:
... INFO org.apache.hadoop.mapred.TaskTracker: task_... 0.25%
reduce > copy (3 of 4 at 0.00 MB/s)
Ger-Jan
Quoting Ming Yang <[EMAIL PROTECTED]>:
Hi,
I am using hadoop 0.14.1 on Ubuntu 7.04 (kernel version 2.6.20)
The Java version is 1.5.0.12. There are no failed tasks and no
lost task trackers.. What I observed is the machine only finished
part of the reduce tasks and became idle. Could the issue come
from my HDFS since the status showed the transfer rate is so low?
Thanks,
Ming
2007/9/30, Arun C Murthy <[EMAIL PROTECTED]>:
Ming Yang,
On Sun, Sep 30, 2007 at 01:13:07PM -0400, Ming Yang wrote:
>Hi,
>
>I set up a 2-node Hadoop cluster, whose nodes are all in
>the same network and ran the 'grep' example. The map tasks
>were distributed among the two machines and ran without any
>problem. However, the reduce task, which is running at the slave
>node, doesn't seem to finish and stops at 11%. I checked the
>reduce task tracker and it shows the following message:
>
>reduce > copy (5 of 15 at 0.00 MB/s) >
>
>Can anyone let me know where the problem comes from?
>and how to fix it? I really appreciate it!
>
Could you provide details on the hadoop version, platform etc.?
Were there any failed tasks, lost task-trackers?
Arun
>Thank you,
>
>Ming Yang
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