Mind.random()

For the past many months i have been out of blogging due to personal reasons. By the Grace of God, things have just turned perfectly good for me.  So, i am back to experimenting with some really cool stuff.

These instructions are an excerpt from

http://www.michael-noll.com/wiki/Running_Hadoop_On_Ubuntu_Linux_(Multi-Node_Cluster)

and Hadoop, HBase API documentation.

1) Download Hadoop (hadoop-0.18.1)
2) Download HBase (hbase-0.18.0)
3) I just setup the environment as Pseudo-Distributed.

a) Open up the hadoop-env.sh file in the conf directory of hadoop. Change the JAVA_HOME directory to point to your own machine setup. Mine looks like this :

export JAVA_HOME=/usr/lib/jvm/java-6-sun-1.6.0.07

b) Open up the hbase-env.sh file in the conf directory of hbase and set JAVA_HOME.

c) Edit hbase-site.xml and make your configuration tag look like this :

<configuration>
<property>
<name>fs.default.name</name>
<value>hdfs://localhost/hbase</value>
</property>
</configuration>

d) Make hadoop-site.xml to look like the following :

<configuration>
<property>
<name>fs.default.name</name>
<value>hdfs://localhost/</value>
</property>
<property>
<name>dfs.replication</name>
<value>1</value>
</property>
</configuration>

e) Issue the following command inside the bin directory of your hadoop
./start-all.sh

eg : arun@arun-laptop:~/softy/hadoop-0.18.1/bin$ ./start-all.sh

f) Issue the following command to start HBase

eg : arun@arun-laptop:~/softy/hbase-0.18.0/bin$ ./start-hbase.sh

You can play with the shell if you wanted to.

arun@arun-laptop:~/softy/hbase-0.18.0/bin$ ./hbase shell

There is an example on http://hadoop.apache.org/hbase/docs/r0.18.0/api/index.html which

i used to test my setup. The example would need us to create a table ‘myTable’ with a column family ‘myColumnFamily’

Execute the following command on the shell

create ‘myTable’,'myColumnFamily’

Here is what i got as output on execution of the example program :

Found row: myRow with value: timestamp=1225023942810, value=columnQualifier1 value!

Let me know if I could help you with any of the setup problems. I didnt copy the hadoop-site.xml to hbase conf. Later i learnt that it is useful only on “truly” distributed environment.

The above setup instructions were just derived from
a) http://hadoop.apache.org/core/docs/r0.18.1/api/index.html
and
b) http://hadoop.apache.org/hbase/docs/r0.18.0/api/index.html

Food for the bots : Here is the list of exceptions i got during the process of setting this up :

INFO  20:39:19 [org.apache.hadoop.hbase.client.HConnectionManager$TableServers (202):getMaster]:

Attempt 0 of 10 failed with <java.io.IOException: Call failed on local exception>.

Retrying after sleep of 5000

Exception in thread “main” org.apache.hadoop.hbase.MasterNotRunningException: localhost:60000

The above log just means that the hbase and hadoop are not started at all. Check the log for exceptions.

Remember, Hadoop must be started first followed by HBase.