How to write simple programs using Hadoop?

Is there any chance to see some simple programs for Hadoop (such as Hello world, counting numbers 1-10, reading two numbers and printing the larger one, other number, string and file processing examples,...etc) written in Java/C++. It seems that the only available public code on the world

Re: How to write simple programs using Hadoop?

On May 7, 2008, at 12:33 AM, Hadoop wrote: Is there any chance to see some simple programs for Hadoop (such as Hello world, counting numbers 1-10, reading two numbers and printing the larger one, other number, string and file processing examples,...etc) written in Java/C++. It seems

Re: Collecting output not to file

Derek Shaw wrote: Hey, From the examples that I have seen thus far, all of the results from the reduce function are being written to a file. Instead of writing results to a file, I want to store them What do you mean by store and inspect? and inspect them after the job is completed. (I

Re: single node Hbase

Try this one http://hadoop.apache.org/hbase/docs/r0.1.1/api/overview-summary.html#overview_description - Yuri. On Wed, May 7, 2008 at 4:40 PM, Ahmed Shiraz Memon [EMAIL PROTECTED] wrote: the link is not working... Shiraz On Mon, Mar 17, 2008 at 9:34 PM, stack [EMAIL PROTECTED] wrote: Try

Not allow file split

Hi at all, I'm a newbie and I have the following problem. I need to implement an InputFormat such that the isSplitable always returns false ah shown in http://wiki.apache.org/hadoop/FAQ (question no 10). And here there is the problem. I have also to implement the RecordReader interface for

Re: Not allow file split

You can implement a custom input format and a record reader. Assuming your record data type is class RecType, the input format should subclass FileInputFormat LongWritable, RecType and the record reader should implement RecordReader LongWritable, RecType In this case the key could be the

Where is the files?

Hi All, I started Hadoop in standalone mode, and put some file on to HDSF. I strictly followed the instructions in Hadoop Quick Start. HDSF is mapped to a local directory in my local file system, right? and where is it? Thank you in advance!

Re: Where is the files?

it will be mapped to /tmp -- equivalanet to drive of HADOOP_ROOT/tmp in windows Regards, -Vikas. On Wed, May 7, 2008 at 8:06 PM, hong [EMAIL PROTECTED] wrote: Hi All, I started Hadoop in standalone mode, and put some file on to HDSF. I strictly followed the instructions in Hadoop Quick

Re: Not allow file split

On May 7, 2008, at 6:30 AM, Roberto Zandonati wrote: Hi at all, I'm a newbie and I have the following problem. I need to implement an InputFormat such that the isSplitable always returns false ah shown in http://wiki.apache.org/hadoop/FAQ (question no 10). And here there is the problem. I

Re: Where is the files?

DFS files are mapped into blocks. Blocks are stored under dfs.data.dir/current. Hairong On 5/7/08 7:36 AM, hong [EMAIL PROTECTED] wrote: Hi All, I started Hadoop in standalone mode, and put some file on to HDSF. I strictly followed the instructions in Hadoop Quick Start. HDSF is mapped

Read timed out, Abandoning block blk_-5476242061384228962

What is this bit of the log trying to tell me, and what sorts of things should I be looking at to make sure it doesn't happen? I don't think the network has any basic configuration issues - I can telnet from the machine creating this log to the destination - telnet 10.252.222.239 50010 works fine

Re: Read timed out, Abandoning block blk_-5476242061384228962

I noticed that there was a hard-coded timeout value of 6000 (ms) in src/java/org/apache/hadoop/dfs/DFSClient.java - as an experiment, I took that way down and now I'm not noticing the problem. (Doesn't mean it's not there, I just don't feel the pain...) This feels like a terrible

Hadoop Permission Problem

Hi, My datanode and jobtracker are started by user hadoop. And user Test needs to submit the job. So if the user Test copies file to HDFS, there is a permission error. /usr/local/hadoop/bin/hadoop dfs -copyFromLocal /home/Test/somefile.txt myapps copyFromLocal:

Re: Read timed out, Abandoning block blk_-5476242061384228962

Taking the timeout out is very dangerous. It may cause your application to hang. You could change the timeout parameter to a larger number. HADOOP-2188 fixed the problem. Check https://issues.apache.org/jira/browse/HADOOP-2188. Hairong On 5/7/08 2:36 PM, James Moore [EMAIL PROTECTED] wrote: I

Re: Read timed out, Abandoning block blk_-5476242061384228962

Hi James Were you able to start all the nodes in the same 'availability zone'? You using the new AMI kernels? If you are using the contrib/ec2 scripts, you might upgrade (just the scripts) to http://svn.apache.org/viewvc/hadoop/core/branches/branch-0.17/src/contrib/ec2/ These support the

Re: Hadoop Permission Problem

Hi Senthil, Since the path myapps is relative, copyFromLocal will copy the file to the home directory, i.e. /user/Test/myapps in your case. If /user/Test doesn't not exist, it will first try to create it. You got AccessControlException because the permission of /user is 755. Hope this

Fwd: Collecting output not to file

To clarify: static class TestOutputFormat implements OutputFormat Text, Text { static class TestRecordWriter implements RecordWriter Text, Text { TestOutputFormat output; public TestRecordWriter