JobTracker webUI stopped showing suddenly
Jobtracker webUI suddenly stopped showing. It was working fine before. What could be the issue ? Can anyone guide me how can I recover my WebUI ? Thanks, Praveenesh
Re: JobTracker webUI stopped showing suddenly
your job tracker is not running On Wed, Jan 11, 2012 at 7:08 PM, praveenesh kumar wrote: > Jobtracker webUI suddenly stopped showing. It was working fine before. > What could be the issue ? Can anyone guide me how can I recover my WebUI ? > > Thanks, > Praveenesh >
Re: JobTracker webUI stopped showing suddenly
Its running,. I am running jobs on hadoop. they are running fine, Thanks, Praveenesh On Wed, Jan 11, 2012 at 7:20 PM, hadoop hive wrote: > your job tracker is not running > > On Wed, Jan 11, 2012 at 7:08 PM, praveenesh kumar >wrote: > > > Jobtracker webUI suddenly stopped showing. It was working fine before. > > What could be the issue ? Can anyone guide me how can I recover my WebUI > ? > > > > Thanks, > > Praveenesh > > >
Similar frameworks like hadoop and taxonomy of distributed computing
Hi, I was wondering if anyone knows any paper discussing and comparing the mentioned topic. I am a little bit confused about the classification of hadoop.. Is it a /cluster/comp grid/ a mix of them? What is hadoop in relation with a cloud - probably just a technology that enables cloud services.. Can it be compared to cluster middleware like beowulf, oscar, condor, sector/sphere, hpcc, dryad, etc? Why not? Like I could read hadoop main field is text processing for problems that are embarrassingly parallel but I cannot define what would be the case for deciding to use other cluster technologies. Probably there are a lot of similarities between then, however any comparison would be helpful. It would be a big help to clarify in which field to classify all those technologies and what are they most suitable for... Thank you
Failed to set permissions of path
hi Hadoops & Nutchs, I'm trying to run Nutch 1.4 *locally*, on Windows 7, using Hadoop 0.20.203.0. I run with: fs.default.name = D:\fs hadoop.tmp.dir = D:\tmp dfs.permissions = false PATH environment variable contains C:\cygwin\bin. I get the following exception: Exception in thread "main" java.io.IOException: *Failed to set permissions of path*: file:/D:/tmp/mapred/staging/username-835169260/.staging to *0700* at org.apache.hadoop.fs.RawLocalFileSystem.*checkReturnValue* (RawLocalFileSystem.java:525) at org.apache.hadoop.fs.RawLocalFileSystem.*setPermission* (RawLocalFileSystem.java:499) at org.apache.hadoop.fs.RawLocalFileSystem.mkdirs(RawLocalFileSystem.java:318) at org.apache.hadoop.fs.FilterFileSystem.mkdirs(FilterFileSystem.java:183) at org.apache.hadoop.mapreduce.JobSubmissionFiles.getStagingDir(JobSubmissionFiles.java:116) at org.apache.hadoop.mapred.JobClient$2.run(JobClient.java:797) at org.apache.hadoop.mapred.JobClient$2.run(JobClient.java:791) at java.security.AccessController.doPrivileged(Native Method) at javax.security.auth.Subject.doAs(Unknown Source) at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1059) at org.apache.hadoop.mapred.JobClient.submitJobInternal(JobClient.java:791) at org.apache.hadoop.mapred.JobClient.submitJob(JobClient.java:765) at org.apache.hadoop.mapred.JobClient.runJob(JobClient.java:1200) at org.apache.nutch.crawl.Injector.inject(Injector.java:217) at org.apache.nutch.crawl.Crawl.run(Crawl.java:127) at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:65) at org.apache.nutch.crawl.Crawl.main(Crawl.java:55) The call to *rv = f.setReadable(group.implies(FsAction.READ), false);*, in RawLocalFileSystem.setPermission (*f* is java.io.File), returns false, and that what causes checkReturnValue to throw the exception. The above .staging folder DOES get created, only setting the permission fails. I also tried Hadoop's hadoop.job.ugi property, giving it different values, with no success. I'm posting in both forums, because I don't know where is the problem. Do you? :-) 10X ShlomiJ
Re: Failed to set permissions of path
(sending email again, because it seems it did not reach forum) On Wed, Jan 11, 2012 at 12:09 PM, shlomi java wrote: > hi Hadoops & Nutchs, > > I'm trying to run Nutch 1.4 *locally*, on Windows 7, using Hadoop > 0.20.203.0. > I run with: > fs.default.name = D:\fs > hadoop.tmp.dir = D:\tmp > dfs.permissions = false > PATH environment variable contains C:\cygwin\bin. > > I get the following exception: > Exception in thread "main" java.io.IOException: *Failed to set > permissions of path*: > file:/D:/tmp/mapred/staging/username-835169260/.staging to *0700* > at org.apache.hadoop.fs.RawLocalFileSystem.*checkReturnValue* > (RawLocalFileSystem.java:525) > at org.apache.hadoop.fs.RawLocalFileSystem.*setPermission* > (RawLocalFileSystem.java:499) > at > org.apache.hadoop.fs.RawLocalFileSystem.mkdirs(RawLocalFileSystem.java:318) > at org.apache.hadoop.fs.FilterFileSystem.mkdirs(FilterFileSystem.java:183) > at > org.apache.hadoop.mapreduce.JobSubmissionFiles.getStagingDir(JobSubmissionFiles.java:116) > at org.apache.hadoop.mapred.JobClient$2.run(JobClient.java:797) > at org.apache.hadoop.mapred.JobClient$2.run(JobClient.java:791) > at java.security.AccessController.doPrivileged(Native Method) > at javax.security.auth.Subject.doAs(Unknown Source) > at > org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1059) > at > org.apache.hadoop.mapred.JobClient.submitJobInternal(JobClient.java:791) > at org.apache.hadoop.mapred.JobClient.submitJob(JobClient.java:765) > at org.apache.hadoop.mapred.JobClient.runJob(JobClient.java:1200) > at org.apache.nutch.crawl.Injector.inject(Injector.java:217) > at org.apache.nutch.crawl.Crawl.run(Crawl.java:127) > at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:65) > at org.apache.nutch.crawl.Crawl.main(Crawl.java:55) > > The call to *rv = f.setReadable(group.implies(FsAction.READ), false);*, > in RawLocalFileSystem.setPermission (*f* is java.io.File), returns false, > and that what causes checkReturnValue to throw the exception. > The above .staging folder DOES get created, only setting the permission > fails. > > I also tried Hadoop's hadoop.job.ugi property, giving it different values, > with no success. > > I'm posting in both forums, because I don't know where is the problem. > > Do you? :-) > > 10X > ShlomiJ >
Re: Similar frameworks like hadoop and taxonomy of distributed computing
I don't know of an academic paper, though this blog post has a nice survey: http://srinathsview.blogspot.com/2011/10/list-of-known-scalable-architecture.html
Re: Similar frameworks like hadoop and taxonomy of distributed computing
Hi, see comments in text On 1/11/2012 4:42 PM, Merto Mertek wrote: Hi, I was wondering if anyone knows any paper discussing and comparing the mentioned topic. I am a little bit confused about the classification of hadoop.. Is it a /cluster/comp grid/ a mix of them? I think that a strict definition would be an implementation of the map-reduce computing paradigm, for cluster usage. What is hadoop in relation with a cloud - probably just a technology that enables cloud services.. It can be used to enable cloud services through a service oriented framework, like we are doing in http://users.ntua.gr/gkousiou/publications/PID2095917.pdf in which we are trying to create a cloud service that offers MapReduce clusters as a service and distributed storage (through HDFS). But this is not the primary usage. This is the back end heavy processing in a cluster-like manner, specifically for parallel jobs that follow the MR logic. Can it be compared to cluster middleware like beowulf, oscar, condor, sector/sphere, hpcc, dryad, etc? Why not? I could see some similarities with condor, mainly in the job submission processes, however i am not really sure how condor deals with parallel jobs. Like I could read hadoop main field is text processing for problems that are embarrassingly parallel but I cannot define what would be the case for deciding to use other cluster technologies. Probably there are a lot of similarities between then, however any comparison would be helpful. Theoretically, you could write the program like an MPI implementation, which is more flexible and is not limited by the MR paradigm. However if you can find a way to convert your problem to a MR job, then the implementation would be much easier (I guess) as a hadoop job, since you will only have to write the Mapper and the Reducer. In MPI you would probably need all the communication framework too. Furthermore, Hadoop has also HDFS, which enables shared storage between the various hadoop components/threads etc. In other clusters you need to set this up specifically, through NFS or something similar (i guess again). My two cents, George It would be a big help to clarify in which field to classify all those technologies and what are they most suitable for... Thank you -- --- George Kousiouris Electrical and Computer Engineer Division of Communications, Electronics and Information Engineering School of Electrical and Computer Engineering Tel: +30 210 772 2546 Mobile: +30 6939354121 Fax: +30 210 772 2569 Email: gkous...@mail.ntua.gr Site: http://users.ntua.gr/gkousiou/ National Technical University of Athens 9 Heroon Polytechniou str., 157 73 Zografou, Athens, Greece
Re: Failed to set permissions of path
This error (specific to Windows) is caused by optimization introduced around
203 and it is still there in 1.0.0 :(. I don't know how to fix it other than
recompile Hadoop common with optimization removed from
RawLocalFileSystem.java
/**
* Use the command chmod to set permission.
*/
@Override
public void setPermission(Path p, FsPermission permission
) throws IOException {
execSetPermission(pathToFile(p), permission);
}
Vlad
-Original Message-
From: shlomi java
Sent: Wednesday, January 11, 2012 6:46 AM
To: common-user@hadoop.apache.org
Subject: Re: Failed to set permissions of path
(sending email again, because it seems it did not reach forum)
On Wed, Jan 11, 2012 at 12:09 PM, shlomi java wrote:
hi Hadoops & Nutchs,
I'm trying to run Nutch 1.4 *locally*, on Windows 7, using Hadoop
0.20.203.0.
I run with:
fs.default.name = D:\fs
hadoop.tmp.dir = D:\tmp
dfs.permissions = false
PATH environment variable contains C:\cygwin\bin.
I get the following exception:
Exception in thread "main" java.io.IOException: *Failed to set
permissions of path*:
file:/D:/tmp/mapred/staging/username-835169260/.staging to *0700*
at org.apache.hadoop.fs.RawLocalFileSystem.*checkReturnValue*
(RawLocalFileSystem.java:525)
at org.apache.hadoop.fs.RawLocalFileSystem.*setPermission*
(RawLocalFileSystem.java:499)
at
org.apache.hadoop.fs.RawLocalFileSystem.mkdirs(RawLocalFileSystem.java:318)
at org.apache.hadoop.fs.FilterFileSystem.mkdirs(FilterFileSystem.java:183)
at
org.apache.hadoop.mapreduce.JobSubmissionFiles.getStagingDir(JobSubmissionFiles.java:116)
at org.apache.hadoop.mapred.JobClient$2.run(JobClient.java:797)
at org.apache.hadoop.mapred.JobClient$2.run(JobClient.java:791)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Unknown Source)
at
org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1059)
at
org.apache.hadoop.mapred.JobClient.submitJobInternal(JobClient.java:791)
at org.apache.hadoop.mapred.JobClient.submitJob(JobClient.java:765)
at org.apache.hadoop.mapred.JobClient.runJob(JobClient.java:1200)
at org.apache.nutch.crawl.Injector.inject(Injector.java:217)
at org.apache.nutch.crawl.Crawl.run(Crawl.java:127)
at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:65)
at org.apache.nutch.crawl.Crawl.main(Crawl.java:55)
The call to *rv = f.setReadable(group.implies(FsAction.READ), false);*,
in RawLocalFileSystem.setPermission (*f* is java.io.File), returns false,
and that what causes checkReturnValue to throw the exception.
The above .staging folder DOES get created, only setting the permission
fails.
I also tried Hadoop's hadoop.job.ugi property, giving it different values,
with no success.
I'm posting in both forums, because I don't know where is the problem.
Do you? :-)
10X
ShlomiJ
Re: connection between slaves and master
exactly right. Thanks Praveen. Mark On Tue, Jan 10, 2012 at 1:54 AM, Praveen Sripati wrote: > Mark, > > > [mark@node67 ~]$ telnet node77 > > You need to specify the port number along with the server name like `telnet > node77 1234`. > > > 2012-01-09 10:04:03,436 INFO org.apache.hadoop.ipc.Client: Retrying > connect to server: localhost/127.0.0.1:12123. Already tried 0 time(s). > > Slaves are not able to connect to the master. The configurations ` > fs.default.name` and `mapred.job.tracker` should point to the master and > not to localhost when the master and slaves are on different machines. > > Praveen > > On Mon, Jan 9, 2012 at 11:41 PM, Mark question > wrote: > > > Hello guys, > > > > I'm requesting from a PBS scheduler a number of machines to run Hadoop > > and even though all hadoop daemons start normally on the master and > slaves, > > the slaves don't have worker tasks in them. Digging into that, there > seems > > to be some blocking between nodes (?) don't know how to describe it > except > > that on slave if I "telnet master-node" it should be able to connect, > but > > I get this error: > > > > [mark@node67 ~]$ telnet node77 > > > > Trying 192.168.1.77... > > telnet: connect to address 192.168.1.77: Connection refused > > telnet: Unable to connect to remote host: Connection refused > > > > The log at the slave nodes shows the same thing, even though it has > > datanode and tasktracker started from the maste (?): > > > > 2012-01-09 10:04:03,436 INFO org.apache.hadoop.ipc.Client: Retrying > > connect > > to server: localhost/127.0.0.1:12123. Already tried 0 time(s). > > 2012-01-09 10:04:04,439 INFO org.apache.hadoop.ipc.Client: Retrying > > connect > > to server: localhost/127.0.0.1:12123. Already tried 1 time(s). > > 2012-01-09 10:04:05,442 INFO org.apache.hadoop.ipc.Client: Retrying > > connect > > to server: localhost/127.0.0.1:12123. Already tried 2 time(s). > > 2012-01-09 10:04:06,444 INFO org.apache.hadoop.ipc.Client: Retrying > > connect > > to server: localhost/127.0.0.1:12123. Already tried 3 time(s). > > 2012-01-09 10:04:07,446 INFO org.apache.hadoop.ipc.Client: Retrying > > connect > > to server: localhost/127.0.0.1:12123. Already tried 4 time(s). > > 2012-01-09 10:04:08,448 INFO org.apache.hadoop.ipc.Client: Retrying > > connect > > to server: localhost/127.0.0.1:12123. Already tried 5 time(s). > > 2012-01-09 10:04:09,450 INFO org.apache.hadoop.ipc.Client: Retrying > > connect > > to server: localhost/127.0.0.1:12123. Already tried 6 time(s). > > 2012-01-09 10:04:10,452 INFO org.apache.hadoop.ipc.Client: Retrying > > connect > > to server: localhost/127.0.0.1:12123. Already tried 7 time(s). > > 2012-01-09 10:04:11,454 INFO org.apache.hadoop.ipc.Client: Retrying > > connect > > to server: localhost/127.0.0.1:12123. Already tried 8 time(s). > > 2012-01-09 10:04:12,456 INFO org.apache.hadoop.ipc.Client: Retrying > > connect > > to server: localhost/127.0.0.1:12123. Already tried 9 time(s). > > 2012-01-09 10:04:12,456 INFO org.apache.hadoop.ipc.RPC: Server at > > localhost/ > > 127.0.0.1:12123 not available yet, Z... > > > > Any suggestions of what I can do? > > > > Thanks, > > Mark > > >
Getting error
-- View this message in context: http://old.nabble.com/Getting-error-tp33123705p33123705.html Sent from the Hadoop core-user mailing list archive at Nabble.com.
Re: Getting error
Arusarka, Take my advice and do not take the error even if you're getting it :) J/k. Seriously though, looks like you sent your email accidentally incomplete. What error are you facing with which component in Hadoop, and how would you like us to help? On 12-Jan-2012, at 1:28 AM, arusarka wrote: > > > -- > View this message in context: > http://old.nabble.com/Getting-error-tp33123705p33123705.html > Sent from the Hadoop core-user mailing list archive at Nabble.com. >
Re: Getting error during namenode -format
export JAVA_HOME="/cygdrive/c/Program\ Files/Java/jdk1.5.0_15" should work. On 1/11/12 3:24 PM, arusarka wrote: Hi: I am in the process of installing hadoop on non-clustered single node windows xp. SSH installed and running. Java version: java version "1.5.0_15" it is installed in c:\Program Files\Java\jdk1.5.0_15 hadoop-env.sh export JAVA_HOME=/cygdrive/c/Program\ Files/Java/jdk1.5.0_15 When I am executing the command bin/hadoop namenode -format I am getting the following error, how to escape "Program Files"? Error: == $ bin/hadoop namenode -format cygpath: can't convert empty path /usr/local/hadoop-0.22.0/bin/hadoop-config.sh: line 194: /cygdrive/c/Program: No such file or directory cygpath: can't convert empty path DEPRECATED: Use of this script to execute hdfs command is deprecated. Instead use the hdfs command for it. cygpath: can't convert empty path C:\cygwin\usr\local\hadoop-0.22.0\/bin/hadoop-config.sh: line 194: /cygdrive/c/Program: No such file or directory cygpath: can't convert empty path java.lang.UnsupportedClassVersionError: Bad version number in .class file at java.lang.ClassLoader.defineClass1(Native Method) at java.lang.ClassLoader.defineClass(ClassLoader.java:620) at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:124) at java.net.URLClassLoader.defineClass(URLClassLoader.java:260) at java.net.URLClassLoader.access$100(URLClassLoader.java:56) at java.net.URLClassLoader$1.run(URLClassLoader.java:195) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(URLClassLoader.java:188) at java.lang.ClassLoader.loadClass(ClassLoader.java:306) at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:268) at java.lang.ClassLoader.loadClass(ClassLoader.java:251) at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:319) Exception in thread "main" NOTE: My previous message was not complete at all, I apologize. Regards, Arup
Re: Similar frameworks like hadoop and taxonomy of distributed computing
On Jan 11, 2012, at 10:15 AM, George Kousiouris wrote:
>
> Hi,
>
> see comments in text
>
> On 1/11/2012 4:42 PM, Merto Mertek wrote:
>> Hi,
>>
>> I was wondering if anyone knows any paper discussing and comparing the
>> mentioned topic. I am a little bit confused about the classification of
>> hadoop.. Is it a /cluster/comp grid/ a mix of them?
> I think that a strict definition would be an implementation of the map-reduce
> computing paradigm, for cluster usage.
>
>> What is hadoop in
>> relation with a cloud - probably just a technology that enables cloud
>> services..
> It can be used to enable cloud services through a service oriented framework,
> like we are doing in
> http://users.ntua.gr/gkousiou/publications/PID2095917.pdf
>
> in which we are trying to create a cloud service that offers MapReduce
> clusters as a service and distributed storage (through HDFS).
> But this is not the primary usage. This is the back end heavy processing in a
> cluster-like manner, specifically for parallel jobs that follow the MR logic.
>
>>
>> Can it be compared to cluster middleware like beowulf, oscar, condor,
>> sector/sphere, hpcc, dryad, etc? Why not?
> I could see some similarities with condor, mainly in the job submission
> processes, however i am not really sure how condor deals with parallel jobs.
>
Since you asked…
Condor has a built-in concept of a set of jobs (called a "job cluster"). On
top of its scheduler, there is a product called "DAGMan" (DAG = directed
acyclic graph) that can manage a large number of jobs with interrelated
dependencies (providing a partial ordering between jobs). Condor with DAG is
somewhat comparable to the concept of Hadoop tasks plus Oozie workflows
(although the data aspects are very different - don't try to stretch it too
far).
Condor / PBS / LSF / {OGE,SGE,GE} / SLURM provide the capability to start many
identical jobs in parallel for MPI-type computations, but I consider MPI wildly
different than the sort of workflows you see with MapReduce. Specifically,
"classic MPI" programming (the ones you see in wide use, MPI2 and later are
improved) mostly requires all processes to start simultaneously and the job
crashes if one process dies. I think this is why the Top10 computers tend to
measure mean time between failure in tens of hours.
Unlike Hadoop, Condor jobs can flow between pools (they call this "flocking")
and pools can naturally cover multiple data centers. The largest demonstration
I'm aware of is 100,000 cores across the US; the largest production pool I'm
aware of is about 20-30k cores across 100 universities/labs on multiple
continents. This is not a criticism of Hadoop - Condor doesn't really have the
same level of data-integration as Hadoop does, so tackles a much simpler
problem (i.e., bring-your-own-data-management!).
Brian
smime.p7s
Description: S/MIME cryptographic signature
Re: Similar frameworks like hadoop and taxonomy of distributed computing
Also check out my paper on The Anatomy and Physiology of the Grid Revisited
just Google for it where we also tried to look at this very issue.
Cheers,
Chris
Sent from my iPhone
On Jan 11, 2012, at 3:55 PM, "Brian Bockelman" wrote:
>
> On Jan 11, 2012, at 10:15 AM, George Kousiouris wrote:
>
>>
>> Hi,
>>
>> see comments in text
>>
>> On 1/11/2012 4:42 PM, Merto Mertek wrote:
>>> Hi,
>>>
>>> I was wondering if anyone knows any paper discussing and comparing the
>>> mentioned topic. I am a little bit confused about the classification of
>>> hadoop.. Is it a /cluster/comp grid/ a mix of them?
>> I think that a strict definition would be an implementation of the
>> map-reduce computing paradigm, for cluster usage.
>>
>>> What is hadoop in
>>> relation with a cloud - probably just a technology that enables cloud
>>> services..
>> It can be used to enable cloud services through a service oriented
>> framework, like we are doing in
>> http://users.ntua.gr/gkousiou/publications/PID2095917.pdf
>>
>> in which we are trying to create a cloud service that offers MapReduce
>> clusters as a service and distributed storage (through HDFS).
>> But this is not the primary usage. This is the back end heavy processing in
>> a cluster-like manner, specifically for parallel jobs that follow the MR
>> logic.
>>
>>>
>>> Can it be compared to cluster middleware like beowulf, oscar, condor,
>>> sector/sphere, hpcc, dryad, etc? Why not?
>> I could see some similarities with condor, mainly in the job submission
>> processes, however i am not really sure how condor deals with parallel jobs.
>>
>
> Since you asked…
>
>
>
> Condor has a built-in concept of a set of jobs (called a "job cluster"). On
> top of its scheduler, there is a product called "DAGMan" (DAG = directed
> acyclic graph) that can manage a large number of jobs with interrelated
> dependencies (providing a partial ordering between jobs). Condor with DAG is
> somewhat comparable to the concept of Hadoop tasks plus Oozie workflows
> (although the data aspects are very different - don't try to stretch it too
> far).
>
> Condor / PBS / LSF / {OGE,SGE,GE} / SLURM provide the capability to start
> many identical jobs in parallel for MPI-type computations, but I consider MPI
> wildly different than the sort of workflows you see with MapReduce.
> Specifically, "classic MPI" programming (the ones you see in wide use, MPI2
> and later are improved) mostly requires all processes to start simultaneously
> and the job crashes if one process dies. I think this is why the Top10
> computers tend to measure mean time between failure in tens of hours.
>
> Unlike Hadoop, Condor jobs can flow between pools (they call this "flocking")
> and pools can naturally cover multiple data centers. The largest
> demonstration I'm aware of is 100,000 cores across the US; the largest
> production pool I'm aware of is about 20-30k cores across 100
> universities/labs on multiple continents. This is not a criticism of Hadoop
> - Condor doesn't really have the same level of data-integration as Hadoop
> does, so tackles a much simpler problem (i.e.,
> bring-your-own-data-management!).
>
>
>
> Brian
>
Re: Similar frameworks like hadoop and taxonomy of distributed computing
Here's some links to it:
Long Version:
http://csse.usc.edu/csse/TECHRPTS/2008/usc-csse-2008-820/usc-csse-2008-820.pdf
Shorter Version (published in WICSA):
http://wwwp.dnsalias.org/w/images/3/3f/AnatomyPhysiologyGridRevisited66.pdf
Cheers,
Chris
On Jan 11, 2012, at 4:02 PM, Mattmann, Chris A (388J) wrote:
> Also check out my paper on The Anatomy and Physiology of the Grid Revisited
> just Google for it where we also tried to look at this very issue.
>
> Cheers,
> Chris
>
> Sent from my iPhone
>
> On Jan 11, 2012, at 3:55 PM, "Brian Bockelman" wrote:
>
>>
>> On Jan 11, 2012, at 10:15 AM, George Kousiouris wrote:
>>
>>>
>>> Hi,
>>>
>>> see comments in text
>>>
>>> On 1/11/2012 4:42 PM, Merto Mertek wrote:
Hi,
I was wondering if anyone knows any paper discussing and comparing the
mentioned topic. I am a little bit confused about the classification of
hadoop.. Is it a /cluster/comp grid/ a mix of them?
>>> I think that a strict definition would be an implementation of the
>>> map-reduce computing paradigm, for cluster usage.
>>>
What is hadoop in
relation with a cloud - probably just a technology that enables cloud
services..
>>> It can be used to enable cloud services through a service oriented
>>> framework, like we are doing in
>>> http://users.ntua.gr/gkousiou/publications/PID2095917.pdf
>>>
>>> in which we are trying to create a cloud service that offers MapReduce
>>> clusters as a service and distributed storage (through HDFS).
>>> But this is not the primary usage. This is the back end heavy processing in
>>> a cluster-like manner, specifically for parallel jobs that follow the MR
>>> logic.
>>>
Can it be compared to cluster middleware like beowulf, oscar, condor,
sector/sphere, hpcc, dryad, etc? Why not?
>>> I could see some similarities with condor, mainly in the job submission
>>> processes, however i am not really sure how condor deals with parallel jobs.
>>>
>>
>> Since you asked…
>>
>>
>>
>> Condor has a built-in concept of a set of jobs (called a "job cluster"). On
>> top of its scheduler, there is a product called "DAGMan" (DAG = directed
>> acyclic graph) that can manage a large number of jobs with interrelated
>> dependencies (providing a partial ordering between jobs). Condor with DAG
>> is somewhat comparable to the concept of Hadoop tasks plus Oozie workflows
>> (although the data aspects are very different - don't try to stretch it too
>> far).
>>
>> Condor / PBS / LSF / {OGE,SGE,GE} / SLURM provide the capability to start
>> many identical jobs in parallel for MPI-type computations, but I consider
>> MPI wildly different than the sort of workflows you see with MapReduce.
>> Specifically, "classic MPI" programming (the ones you see in wide use, MPI2
>> and later are improved) mostly requires all processes to start
>> simultaneously and the job crashes if one process dies. I think this is why
>> the Top10 computers tend to measure mean time between failure in tens of
>> hours.
>>
>> Unlike Hadoop, Condor jobs can flow between pools (they call this
>> "flocking") and pools can naturally cover multiple data centers. The
>> largest demonstration I'm aware of is 100,000 cores across the US; the
>> largest production pool I'm aware of is about 20-30k cores across 100
>> universities/labs on multiple continents. This is not a criticism of Hadoop
>> - Condor doesn't really have the same level of data-integration as Hadoop
>> does, so tackles a much simpler problem (i.e.,
>> bring-your-own-data-management!).
>>
>>
>>
>> Brian
>>
++
Chris Mattmann, Ph.D.
Senior Computer Scientist
NASA Jet Propulsion Laboratory Pasadena, CA 91109 USA
Office: 171-266B, Mailstop: 171-246
Email: chris.a.mattm...@nasa.gov
WWW: http://sunset.usc.edu/~mattmann/
++
Adjunct Assistant Professor, Computer Science Department
University of Southern California, Los Angeles, CA 90089 USA
++
setting mapred.map.child.java.opts not working
Hi, Can someone help me asap? when i run my mapred job, it fails with this error - 12/01/12 02:58:36 INFO mapred.JobClient: Task Id : attempt_201112151554_0050_m_71_0, Status : FAILED Error: Java heap space attempt_201112151554_0050_m_71_0: log4j:ERROR Failed to flush writer, attempt_201112151554_0050_m_71_0: java.io.IOException: Stream closed attempt_201112151554_0050_m_71_0: at sun.nio.cs.StreamEncoder.ensureOpen(StreamEncoder.java:44) attempt_201112151554_0050_m_71_0: at sun.nio.cs.StreamEncoder.flush(StreamEncoder.java:139) attempt_201112151554_0050_m_71_0: at java.io.OutputStreamWriter.flush(OutputStreamWriter.java:229) attempt_201112151554_0050_m_71_0: at org.apache.log4j.helpers.QuietWriter.flush(QuietWriter.java:58) attempt_201112151554_0050_m_71_0: at org.apache.hadoop.mapred.TaskLogAppender.flush(TaskLogAppender.java:94) attempt_201112151554_0050_m_71_0: at org.apache.hadoop.mapred.TaskLog.syncLogs(TaskLog.java:260) attempt_201112151554_0050_m_71_0: at org.apache.hadoop.mapred.Child$2.run(Child.java:142) so i updated my mapred-site.xml with these settings - mapred.map.child.java.opts -Xmx2048M mapred.reduce.child.java.opts -Xmx2048M also, when i run my jar, i provide - "-Dmapred.map.child.java.opts="-Xmx4000m" at the end. inspite of this, the task is not getting the max heap size im setting. where did i go wrong? after changing mapred-site.xml, i restarted jobtracker and tasktracker.. is that not good enough? thanks
Re: setting mapred.map.child.java.opts not working
These properties are not available on Apache Hadoop 1.0 (Formerly known as 0.20.x). This was a feature introduced in 0.21 (https://issues.apache.org/jira/browse/MAPREDUCE-478), and is available today on 0.22 and 0.23 line of releases. For 1.0/0.20, use "mapred.child.java.opts", that applies to both map and reduce commonly. Would also be helpful if you can tell us what doc guided you to use these property names instead of the proper one, so we can fix it. On Thu, Jan 12, 2012 at 8:44 AM, T Vinod Gupta wrote: > Hi, > Can someone help me asap? when i run my mapred job, it fails with this > error - > 12/01/12 02:58:36 INFO mapred.JobClient: Task Id : > attempt_201112151554_0050_m_71_0, Status : FAILED > Error: Java heap space > attempt_201112151554_0050_m_71_0: log4j:ERROR Failed to flush writer, > attempt_201112151554_0050_m_71_0: java.io.IOException: Stream closed > attempt_201112151554_0050_m_71_0: at > sun.nio.cs.StreamEncoder.ensureOpen(StreamEncoder.java:44) > attempt_201112151554_0050_m_71_0: at > sun.nio.cs.StreamEncoder.flush(StreamEncoder.java:139) > attempt_201112151554_0050_m_71_0: at > java.io.OutputStreamWriter.flush(OutputStreamWriter.java:229) > attempt_201112151554_0050_m_71_0: at > org.apache.log4j.helpers.QuietWriter.flush(QuietWriter.java:58) > attempt_201112151554_0050_m_71_0: at > org.apache.hadoop.mapred.TaskLogAppender.flush(TaskLogAppender.java:94) > attempt_201112151554_0050_m_71_0: at > org.apache.hadoop.mapred.TaskLog.syncLogs(TaskLog.java:260) > attempt_201112151554_0050_m_71_0: at > org.apache.hadoop.mapred.Child$2.run(Child.java:142) > > > so i updated my mapred-site.xml with these settings - > > > mapred.map.child.java.opts > -Xmx2048M > > > > mapred.reduce.child.java.opts > -Xmx2048M > > > also, when i run my jar, i provide - > "-Dmapred.map.child.java.opts="-Xmx4000m" at the end. > inspite of this, the task is not getting the max heap size im setting. > > where did i go wrong? > > after changing mapred-site.xml, i restarted jobtracker and tasktracker.. is > that not good enough? > > thanks -- Harsh J
Re: setting mapred.map.child.java.opts not working
Hi Harsh, Wasn't MAPREDUCE-478 in 1.0 ? Maybe the Jira is not up to date. Koji On 1/11/12 8:44 PM, "Harsh J" wrote: > These properties are not available on Apache Hadoop 1.0 (Formerly > known as 0.20.x). This was a feature introduced in 0.21 > (https://issues.apache.org/jira/browse/MAPREDUCE-478), and is > available today on 0.22 and 0.23 line of releases. > > For 1.0/0.20, use "mapred.child.java.opts", that applies to both map > and reduce commonly. > > Would also be helpful if you can tell us what doc guided you to use > these property names instead of the proper one, so we can fix it. > > On Thu, Jan 12, 2012 at 8:44 AM, T Vinod Gupta wrote: >> Hi, >> Can someone help me asap? when i run my mapred job, it fails with this >> error - >> 12/01/12 02:58:36 INFO mapred.JobClient: Task Id : >> attempt_201112151554_0050_m_71_0, Status : FAILED >> Error: Java heap space >> attempt_201112151554_0050_m_71_0: log4j:ERROR Failed to flush writer, >> attempt_201112151554_0050_m_71_0: java.io.IOException: Stream closed >> attempt_201112151554_0050_m_71_0: at >> sun.nio.cs.StreamEncoder.ensureOpen(StreamEncoder.java:44) >> attempt_201112151554_0050_m_71_0: at >> sun.nio.cs.StreamEncoder.flush(StreamEncoder.java:139) >> attempt_201112151554_0050_m_71_0: at >> java.io.OutputStreamWriter.flush(OutputStreamWriter.java:229) >> attempt_201112151554_0050_m_71_0: at >> org.apache.log4j.helpers.QuietWriter.flush(QuietWriter.java:58) >> attempt_201112151554_0050_m_71_0: at >> org.apache.hadoop.mapred.TaskLogAppender.flush(TaskLogAppender.java:94) >> attempt_201112151554_0050_m_71_0: at >> org.apache.hadoop.mapred.TaskLog.syncLogs(TaskLog.java:260) >> attempt_201112151554_0050_m_71_0: at >> org.apache.hadoop.mapred.Child$2.run(Child.java:142) >> >> >> so i updated my mapred-site.xml with these settings - >> >> >> mapred.map.child.java.opts >> -Xmx2048M >> >> >> >> mapred.reduce.child.java.opts >> -Xmx2048M >> >> >> also, when i run my jar, i provide - >> "-Dmapred.map.child.java.opts="-Xmx4000m" at the end. >> inspite of this, the task is not getting the max heap size im setting. >> >> where did i go wrong? >> >> after changing mapred-site.xml, i restarted jobtracker and tasktracker.. is >> that not good enough? >> >> thanks > >
Re: setting mapred.map.child.java.opts not working
Koji, Harsh mapred-478 seems to be in v1, but those new settings have not yet been added to mapred-default.xml. (for backwards compatibility?) George On 2012/01/12 13:50, Koji Noguchi wrote: Hi Harsh, Wasn't MAPREDUCE-478 in 1.0 ? Maybe the Jira is not up to date. Koji On 1/11/12 8:44 PM, "Harsh J" wrote: These properties are not available on Apache Hadoop 1.0 (Formerly known as 0.20.x). This was a feature introduced in 0.21 (https://issues.apache.org/jira/browse/MAPREDUCE-478), and is available today on 0.22 and 0.23 line of releases. For 1.0/0.20, use "mapred.child.java.opts", that applies to both map and reduce commonly. Would also be helpful if you can tell us what doc guided you to use these property names instead of the proper one, so we can fix it. On Thu, Jan 12, 2012 at 8:44 AM, T Vinod Gupta wrote: Hi, Can someone help me asap? when i run my mapred job, it fails with this error - 12/01/12 02:58:36 INFO mapred.JobClient: Task Id : attempt_201112151554_0050_m_71_0, Status : FAILED Error: Java heap space attempt_201112151554_0050_m_71_0: log4j:ERROR Failed to flush writer, attempt_201112151554_0050_m_71_0: java.io.IOException: Stream closed attempt_201112151554_0050_m_71_0: at sun.nio.cs.StreamEncoder.ensureOpen(StreamEncoder.java:44) attempt_201112151554_0050_m_71_0: at sun.nio.cs.StreamEncoder.flush(StreamEncoder.java:139) attempt_201112151554_0050_m_71_0: at java.io.OutputStreamWriter.flush(OutputStreamWriter.java:229) attempt_201112151554_0050_m_71_0: at org.apache.log4j.helpers.QuietWriter.flush(QuietWriter.java:58) attempt_201112151554_0050_m_71_0: at org.apache.hadoop.mapred.TaskLogAppender.flush(TaskLogAppender.java:94) attempt_201112151554_0050_m_71_0: at org.apache.hadoop.mapred.TaskLog.syncLogs(TaskLog.java:260) attempt_201112151554_0050_m_71_0: at org.apache.hadoop.mapred.Child$2.run(Child.java:142) so i updated my mapred-site.xml with these settings - mapred.map.child.java.opts -Xmx2048M mapred.reduce.child.java.opts -Xmx2048M also, when i run my jar, i provide - "-Dmapred.map.child.java.opts="-Xmx4000m" at the end. inspite of this, the task is not getting the max heap size im setting. where did i go wrong? after changing mapred-site.xml, i restarted jobtracker and tasktracker.. is that not good enough? thanks
Re: JobTracker webUI stopped showing suddenly
Guys, any updates on this. My jobtracker is running fine. I am able to submit the jobs also. Jobs are running fine also. Not seeing any thing unusual at logs also. Only the Jobtracker webpage is not displaying. Doing netstat -ptlen on Jobtracker node, also showing jobtracker port 50030 is open. Please guide me.. why its happening like this ? Thanks, Praveenesh On Wed, Jan 11, 2012 at 7:32 PM, praveenesh kumar wrote: > Its running,. > I am running jobs on hadoop. they are running fine, > > Thanks, > Praveenesh > > > On Wed, Jan 11, 2012 at 7:20 PM, hadoop hive wrote: > >> your job tracker is not running >> >> On Wed, Jan 11, 2012 at 7:08 PM, praveenesh kumar > >wrote: >> >> > Jobtracker webUI suddenly stopped showing. It was working fine before. >> > What could be the issue ? Can anyone guide me how can I recover my >> WebUI ? >> > >> > Thanks, >> > Praveenesh >> > >> > >
Re: setting mapred.map.child.java.opts not working
@Koji - Ah, I had not checked the sources, rather just the JIRA, which I've updated now since there is indeed an svn commit listed there. Thanks for correcting me there! @George - I do not think it matters if these are present in default, but they should be present, yes. Mind filing a JIRA if this is still not the case in 0.23+? @Vinod - Do you see these props you set appear in your submitted job.xml? What does your job do exactly, and how much of RAM:Slots are configured/available for your slave machine? On 12-Jan-2012, at 11:04 AM, George Datskos wrote: > Koji, Harsh > > mapred-478 seems to be in v1, but those new settings have not yet been added > to mapred-default.xml. (for backwards compatibility?) > > > George > > On 2012/01/12 13:50, Koji Noguchi wrote: >> Hi Harsh, >> >> Wasn't MAPREDUCE-478 in 1.0 ? Maybe the Jira is not up to date. >> >> Koji >> >> >> On 1/11/12 8:44 PM, "Harsh J" wrote: >> >>> These properties are not available on Apache Hadoop 1.0 (Formerly >>> known as 0.20.x). This was a feature introduced in 0.21 >>> (https://issues.apache.org/jira/browse/MAPREDUCE-478), and is >>> available today on 0.22 and 0.23 line of releases. >>> >>> For 1.0/0.20, use "mapred.child.java.opts", that applies to both map >>> and reduce commonly. >>> >>> Would also be helpful if you can tell us what doc guided you to use >>> these property names instead of the proper one, so we can fix it. >>> >>> On Thu, Jan 12, 2012 at 8:44 AM, T Vinod Gupta >>> wrote: Hi, Can someone help me asap? when i run my mapred job, it fails with this error - 12/01/12 02:58:36 INFO mapred.JobClient: Task Id : attempt_201112151554_0050_m_71_0, Status : FAILED Error: Java heap space attempt_201112151554_0050_m_71_0: log4j:ERROR Failed to flush writer, attempt_201112151554_0050_m_71_0: java.io.IOException: Stream closed attempt_201112151554_0050_m_71_0: at sun.nio.cs.StreamEncoder.ensureOpen(StreamEncoder.java:44) attempt_201112151554_0050_m_71_0: at sun.nio.cs.StreamEncoder.flush(StreamEncoder.java:139) attempt_201112151554_0050_m_71_0: at java.io.OutputStreamWriter.flush(OutputStreamWriter.java:229) attempt_201112151554_0050_m_71_0: at org.apache.log4j.helpers.QuietWriter.flush(QuietWriter.java:58) attempt_201112151554_0050_m_71_0: at org.apache.hadoop.mapred.TaskLogAppender.flush(TaskLogAppender.java:94) attempt_201112151554_0050_m_71_0: at org.apache.hadoop.mapred.TaskLog.syncLogs(TaskLog.java:260) attempt_201112151554_0050_m_71_0: at org.apache.hadoop.mapred.Child$2.run(Child.java:142) so i updated my mapred-site.xml with these settings - mapred.map.child.java.opts -Xmx2048M mapred.reduce.child.java.opts -Xmx2048M also, when i run my jar, i provide - "-Dmapred.map.child.java.opts="-Xmx4000m" at the end. inspite of this, the task is not getting the max heap size im setting. where did i go wrong? after changing mapred-site.xml, i restarted jobtracker and tasktracker.. is that not good enough? thanks >> > >
Re: setting mapred.map.child.java.opts not working
> but those new settings have not yet been
> added to mapred-default.xml.
>
It's intentionally left out.
If set in mapred-default.xml, user's mapred.child.java.opts would be ignored
since mapred.{map,reduce}.child.java.opts would always win.
Koji
On 1/11/12 9:34 PM, "George Datskos" wrote:
> Koji, Harsh
>
> mapred-478 seems to be in v1, but those new settings have not yet been
> added to mapred-default.xml. (for backwards compatibility?)
>
>
> George
>
> On 2012/01/12 13:50, Koji Noguchi wrote:
>> Hi Harsh,
>>
>> Wasn't MAPREDUCE-478 in 1.0 ? Maybe the Jira is not up to date.
>>
>> Koji
>>
>>
>> On 1/11/12 8:44 PM, "Harsh J" wrote:
>>
>>> These properties are not available on Apache Hadoop 1.0 (Formerly
>>> known as 0.20.x). This was a feature introduced in 0.21
>>> (https://issues.apache.org/jira/browse/MAPREDUCE-478), and is
>>> available today on 0.22 and 0.23 line of releases.
>>>
>>> For 1.0/0.20, use "mapred.child.java.opts", that applies to both map
>>> and reduce commonly.
>>>
>>> Would also be helpful if you can tell us what doc guided you to use
>>> these property names instead of the proper one, so we can fix it.
>>>
>>> On Thu, Jan 12, 2012 at 8:44 AM, T Vinod Gupta
>>> wrote:
Hi,
Can someone help me asap? when i run my mapred job, it fails with this
error -
12/01/12 02:58:36 INFO mapred.JobClient: Task Id :
attempt_201112151554_0050_m_71_0, Status : FAILED
Error: Java heap space
attempt_201112151554_0050_m_71_0: log4j:ERROR Failed to flush writer,
attempt_201112151554_0050_m_71_0: java.io.IOException: Stream closed
attempt_201112151554_0050_m_71_0: at
sun.nio.cs.StreamEncoder.ensureOpen(StreamEncoder.java:44)
attempt_201112151554_0050_m_71_0: at
sun.nio.cs.StreamEncoder.flush(StreamEncoder.java:139)
attempt_201112151554_0050_m_71_0: at
java.io.OutputStreamWriter.flush(OutputStreamWriter.java:229)
attempt_201112151554_0050_m_71_0: at
org.apache.log4j.helpers.QuietWriter.flush(QuietWriter.java:58)
attempt_201112151554_0050_m_71_0: at
org.apache.hadoop.mapred.TaskLogAppender.flush(TaskLogAppender.java:94)
attempt_201112151554_0050_m_71_0: at
org.apache.hadoop.mapred.TaskLog.syncLogs(TaskLog.java:260)
attempt_201112151554_0050_m_71_0: at
org.apache.hadoop.mapred.Child$2.run(Child.java:142)
so i updated my mapred-site.xml with these settings -
mapred.map.child.java.opts
-Xmx2048M
mapred.reduce.child.java.opts
-Xmx2048M
also, when i run my jar, i provide -
"-Dmapred.map.child.java.opts="-Xmx4000m" at the end.
inspite of this, the task is not getting the max heap size im setting.
where did i go wrong?
after changing mapred-site.xml, i restarted jobtracker and tasktracker.. is
that not good enough?
thanks
>>
>
>
Re: setting mapred.map.child.java.opts not working
Harsh, did you mean my _conf.xml? for some strange reason, i do see
these 3 lines -
mapred.reduce.child.java.opts-Xmx2048M
mapred.child.java.opts-Xmx200m
mapred.map.child.java.opts-Xmx2048M
the 1st and 3rd is what i set. but i don't know if the middle property
overrides the others.
btw, my hadoop version is below -
Hadoop 0.20.2-cdh3u1
Subversion file:///tmp/topdir/BUILD/hadoop-0.20.2-cdh3u1 -r
bdafb1dbffd0d5f2fbc6ee022e1c8df6500fd638
Compiled by root on Mon Jul 18 09:40:22 PDT 2011
>From source with checksum 3127e3d410455d2bacbff7673bf3284c
thanks
On Wed, Jan 11, 2012 at 10:57 PM, Koji Noguchi wrote:
> > but those new settings have not yet been
> > added to mapred-default.xml.
> >
> It's intentionally left out.
> If set in mapred-default.xml, user's mapred.child.java.opts would be
> ignored
> since mapred.{map,reduce}.child.java.opts would always win.
>
> Koji
>
> On 1/11/12 9:34 PM, "George Datskos"
> wrote:
>
> > Koji, Harsh
> >
> > mapred-478 seems to be in v1, but those new settings have not yet been
> > added to mapred-default.xml. (for backwards compatibility?)
> >
> >
> > George
> >
> > On 2012/01/12 13:50, Koji Noguchi wrote:
> >> Hi Harsh,
> >>
> >> Wasn't MAPREDUCE-478 in 1.0 ? Maybe the Jira is not up to date.
> >>
> >> Koji
> >>
> >>
> >> On 1/11/12 8:44 PM, "Harsh J" wrote:
> >>
> >>> These properties are not available on Apache Hadoop 1.0 (Formerly
> >>> known as 0.20.x). This was a feature introduced in 0.21
> >>> (https://issues.apache.org/jira/browse/MAPREDUCE-478), and is
> >>> available today on 0.22 and 0.23 line of releases.
> >>>
> >>> For 1.0/0.20, use "mapred.child.java.opts", that applies to both map
> >>> and reduce commonly.
> >>>
> >>> Would also be helpful if you can tell us what doc guided you to use
> >>> these property names instead of the proper one, so we can fix it.
> >>>
> >>> On Thu, Jan 12, 2012 at 8:44 AM, T Vinod Gupta
> >>> wrote:
> Hi,
> Can someone help me asap? when i run my mapred job, it fails with this
> error -
> 12/01/12 02:58:36 INFO mapred.JobClient: Task Id :
> attempt_201112151554_0050_m_71_0, Status : FAILED
> Error: Java heap space
> attempt_201112151554_0050_m_71_0: log4j:ERROR Failed to flush
> writer,
> attempt_201112151554_0050_m_71_0: java.io.IOException: Stream
> closed
> attempt_201112151554_0050_m_71_0: at
> sun.nio.cs.StreamEncoder.ensureOpen(StreamEncoder.java:44)
> attempt_201112151554_0050_m_71_0: at
> sun.nio.cs.StreamEncoder.flush(StreamEncoder.java:139)
> attempt_201112151554_0050_m_71_0: at
> java.io.OutputStreamWriter.flush(OutputStreamWriter.java:229)
> attempt_201112151554_0050_m_71_0: at
> org.apache.log4j.helpers.QuietWriter.flush(QuietWriter.java:58)
> attempt_201112151554_0050_m_71_0: at
>
> org.apache.hadoop.mapred.TaskLogAppender.flush(TaskLogAppender.java:94)
> attempt_201112151554_0050_m_71_0: at
> org.apache.hadoop.mapred.TaskLog.syncLogs(TaskLog.java:260)
> attempt_201112151554_0050_m_71_0: at
> org.apache.hadoop.mapred.Child$2.run(Child.java:142)
>
>
> so i updated my mapred-site.xml with these settings -
>
>
> mapred.map.child.java.opts
> -Xmx2048M
>
>
>
> mapred.reduce.child.java.opts
> -Xmx2048M
>
>
> also, when i run my jar, i provide -
> "-Dmapred.map.child.java.opts="-Xmx4000m" at the end.
> inspite of this, the task is not getting the max heap size im setting.
>
> where did i go wrong?
>
> after changing mapred-site.xml, i restarted jobtracker and
> tasktracker.. is
> that not good enough?
>
> thanks
> >>
> >
> >
>
>
