hadoop-common-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Ming Yang" <minghs...@gmail.com>
Subject Re: Slow reduce task
Date Mon, 01 Oct 2007 12:36:54 GMT
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 <arunc@yahoo-inc.com>:
> 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
>

Mime
View raw message