Comments for ole-martin.net

Comment on HBase tutorial for beginners by kiran

kiran — Mon, 16 Apr 2012 05:49:28 +0000

Its very Good Tutorial, it would be great help if i get more good explanations as you mentioned

Comment on HBase tutorial for beginners by timekiller

timekiller — Thu, 12 Apr 2012 22:26:32 +0000

The code above is very out of date. I made the minimum number of necessary adjustments to just get it compiling and running with HBase 0.90.4. It’s clearly in poor form now in a number of ways, but I figured I’d post it anyway, you can clean it up from here…

import org.apache.hadoop.hbase.client.HTable;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.client.Result;
import org.apache.hadoop.hbase.KeyValue;
import org.apache.hadoop.hbase.client.Get;
import org.apache.hadoop.hbase.util.Bytes;

import java.util.HashMap;
import java.util.Map;
import java.io.IOException;

public class HBaseConnector {

public static Map retreivePost(String postId) throws IOException {
HTable table = new HTable(new HBaseConfiguration(), “blogposts”);
Map post = new HashMap();

Result result = table.get(new Get(Bytes.toBytes(postId)));

for (KeyValue column : result.list()) {

post.put(new String(column.getFamily()) + “:” + new String(column.getQualifier()), new String(column.getValue()));
}
return post;
}

public static void main(String[] args) throws IOException {
Map blogpost = HBaseConnector.retreivePost(“post1″);
System.out.println(blogpost.get(“post:title”));
System.out.println(blogpost.get(“post:author”));
}
}

Comment on HBase tutorial for beginners by amsal

amsal — Thu, 08 Mar 2012 09:38:11 +0000

hi
i have created a table in hbase with 12 columns in each row and each column has 8 qualifiers.when i try to read complete row it returns correct value for 1:1 in row 1 but returns null for 1:2
it reads all the columns correctly from 2 to 12….
plz help how to solve this problem
i m using this code for reading….it is inside for loop thar runs from 1 to 10..

train[0][i] = Double.parseDouble(Bytes.toString (r.getValue (Bytes.toBytes(Integer.toString(i)),Bytes.toBytes(“1″))));

train[1][i] = Double.parseDouble (Bytes.toString (r.getValue (Bytes.toBytes(Integer.toString(i)), Bytes.toBytes(“2″))));

train[2][i] = Double.parseDouble (Bytes.toString (r.getValue (Bytes.toBytes(Integer.toString(i)), Bytes.toBytes(“3″))));

train[3][i] = Double.parseDouble (Bytes.toString (r.getValue (Bytes.toBytes(Integer.toString(i)), Bytes.toBytes(“4″))));

train[4][i] = Double.parseDouble (Bytes.toString (r.getValue (Bytes.toBytes(Integer.toString(i)), Bytes.toBytes(“5″))));

train[5][i] = Double.parseDouble (Bytes.toString (r.getValue (Bytes.toBytes(Integer.toString(i)), Bytes.toBytes(“6″))));

train[6][i] = Double.parseDouble (Bytes.toString (r.getValue (Bytes.toBytes(Integer.toString(i)), Bytes.toBytes(“7″))));

train[7][i] = Double.parseDouble (Bytes.toString (r.getValue (Bytes.toBytes(Integer.toString(i)), Bytes.toBytes(“8″))));

Comment on HBase tutorial for beginners by tahreem

tahreem — Tue, 21 Feb 2012 06:51:50 +0000

hey ive been trying dis code but its not executing the compiler says
package org.apache.hadoop.hbase.client does not exist.
import org.apache.hadoop.hbase.client.HTable .

package org.apache.hadoop.hbase does not exist.
import org.apache.hadoop.hbase.HBaseConfiguration.

package org.apache.hadoop.hbase.io does not exist.
import org.apache.hadoop.hbase.io.RowResult.

plz help asap.

Comment on HBase tutorial for beginners by ole-martin

ole-martin — Wed, 21 Dec 2011 12:19:42 +0000

This post is old Rahul. There might have been some changes to the hbase api since then.
What does your compiler say?

Comment on HBase tutorial for beginners by Rahul

Rahul — Wed, 21 Dec 2011 12:10:24 +0000

Hi
Can anybody tell me how to compile and run the HBaseConnecto program which is given in above tutorial .
I tried a lot but not successful if anybody knows any link please share.
Kindly Help.
Thanks

Comment on HBase tutorial for beginners by hbase | riding in tech world.

hbase | riding in tech world. — Fri, 02 Dec 2011 05:04:34 +0000

[...] good tutorial for beginners: http://ole-martin.net/hbase-tutorial-for-beginners/ [...]

Comment on HBase tutorial for beginners by HBase tutorial for beginners « meisterxu

HBase tutorial for beginners « meisterxu — Thu, 18 Aug 2011 08:08:22 +0000

[...] HBase tutorial for beginners From ole-martin.net » HBase tutorial for beginners – a blog by Ole-Martin Mørk. [...]

Comment on HBase tutorial for beginners by Ramesh Babu

Ramesh Babu — Mon, 06 Jun 2011 20:11:38 +0000

Check your IP address in the Host File and it should match the local machine IP

Comment on HBase tutorial for beginners by Misty

Misty — Mon, 02 May 2011 12:51:59 +0000

Can you please guide me how to use HBase in Java programs, I tried running your example but it gives this error

11/05/02 17:44:40 INFO ipc.Client: Retrying connect to server: localhost/127.0.0.1:60000. Already tried 0 time(s).
11/05/02 17:44:42 INFO ipc.Client: Retrying connect to server: localhost/127.0.0.1:60000. Already tried 1 time(s).
11/05/02 17:44:44 INFO ipc.Client: Retrying connect to server: localhost/127.0.0.1:60000. Already tried 2 time(s).
11/05/02 17:44:46 INFO ipc.Client: Retrying connect to server: localhost/127.0.0.1:60000. Already tried 3 time(s).
11/05/02 17:44:48 INFO ipc.Client: Retrying connect to server: localhost/127.0.0.1:60000. Already tried 4 time(s).
11/05/02 17:44:50 INFO ipc.Client: Retrying connect to server: localhost/127.0.0.1:60000. Already tried 5 time(s).
11/05/02 17:44:52 INFO ipc.Client: Retrying connect to server: localhost/127.0.0.1:60000. Already tried 6 time(s).
11/05/02 17:44:54 INFO ipc.Client: Retrying connect to server: localhost/127.0.0.1:60000. Already tried 7 time(s).
11/05/02 17:44:56 INFO ipc.Client: Retrying connect to server: localhost/127.0.0.1:60000. Already tried 8 time(s).
11/05/02 17:44:58 INFO ipc.Client: Retrying connect to server: localhost/127.0.0.1:60000. Already tried 9 time(s).
11/05/02 17:44:59 INFO client.HConnectionManager$TableServers: Attempt 0 of 10 failed with . Retrying after sleep of 2000

please let me know where am i going wrong. please suggest a simple way to use HBase