The readFields and write method is empty ?
When data is transfered from map phase to reduce phase, data is serialized
and deserialized , so the write and readFields will be called. You should
not leave them empty.
Jeff Zhang
On Tue, Dec 29, 2009 at 1:29 PM, bharath v <
bharathvissapragada1...@
Hi ,
I've implemented a simple VectorWritable class as follows
package com;
import org.apache.hadoop.*;
import org.apache.hadoop.io.*;
import java.io.*;
import java.util.Vector;
public class VectorWritable implements WritableComparable {
private Vector value = new Vector();
public Vector
Regarding the ability to include other files in configuration files:
http://issues.apache.org/jira/browse/HADOOP-4944
I'm seeing apparent differing behavior that may make sense to someone. I say
I have my core-site.xml as follows:
http://www.w3.org/2001/XInclude";>
include-site.
Thanks for pointing that out Edward, I'll take a look at the most
recent documentation on HOD.
On Mon, Dec 28, 2009 at 7:39 PM, Edward Capriolo wrote:
> Jim,
>
> Most components of hadoop now have a document branch per release, that
> documentation is inline and is generated by forest. Anything t
Hi.
Going back to the subject, has anyone ever bench-marked small (10 - 20 node)
HDFS clusters?
I did my own speed checks, and it seems I can reach ~77Mbps, on a quad-disk
node. This comes to ~19Mbps per disk, which seems quite low in my opinion.
Can anyone advice about this?
Thanks.
Hi all,
I need your help on multiple file output. I have many big files and I hope the
processing result of each file is outputted to a separate file. I know in the
old Hadoop APIs, the class MultipleOutputFormat works for this propose. But I
cannot find the same class in new APIs. Does anybod
Jim,
Most components of hadoop now have a document branch per release, that
documentation is inline and is generated by forest. Anything that you
find not on the wiki, with a version number, should have a more up to
date page.
For example:
http://hadoop.apache.org/common/
Drop down 'Documentatio
the point is that in java everything is an object, the byte[ ] as well
so when you call byte[].toString() as usual you get '[', a letter that
defines the type 'B', then comes '@' and then the hash code
this is the standard toString() implementation for the array object
I would recommend to impleme
Hi,
I'd like to get Hadoop running on a large University cluster which is
used by many people to run different types of applications. We are
currently using Torque to assign nodes and manage the queue. What I
want to do is to enable people to request "n" processors, and
automatically start Hadoop
Furthermore, Text is meant for use when you have a UTF8-encoded string.
Creating a Text object from a byte array that is not proper UTF-8 is likely
to result in some kind of exception or data mangling. You should use
BytesWritable for this purpose
-Todd
2009/12/28 Edward Capriolo
> Calling bitA
Calling bitArray.toString() does not return your data. You can test
this in a standalong program.
You need to write the array out bitwise or byte wise. toString() does
not do what you want.
Edward
2009/12/28 Gang Luo :
> Hi all,
> I don't know too much about text coding and there is one thing con
Hi,
I'm really frustrated because I've already lost some days trying to
deploy hadoop but it doesn't work.
If I deploy in a single cluster all things work ok (the mapreduce
example as well the deployment).
However when I try to install hadoop in a cluster the problems appear.
The conf
Hi all,
I don't know too much about text coding and there is one thing confusing me. I
am implementing the bloom filter in mapreduce. The output is a bit array
(implemented as byte[ ]) and the length is 2 exp 24 (that means, 2exp21 bytes).
The size of the array should be 2 mb. But when I output
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