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From n keywal <nkey...@gmail.com>
Subject Re: Hbase clustering
Date Thu, 27 Sep 2012 07:51:53 GMT
You should launch the master only once, on whatever machine you like. Then
you will be able to access it from any other machine.
Please have a look at the blog I mentioned in my previous mail.

On Thu, Sep 27, 2012 at 9:39 AM, Venkateswara Rao Dokku <dvrao.584@gmail.com
> wrote:

> I can see that HMaster is not started on the data-node machine when the
> start scripts in hadoop & hbase ran on the hadoop-namenode. My doubt is
> that,Shall we have to start that master on the hadoop-datanode1 too or the
> hadoop-datanode1 will access the Hmaster that is running on the
> hadoop-namenode to create,list,scan tables as the two nodes are in the
> cluster as namenode & datanode.
>
> On Thu, Sep 27, 2012 at 1:02 PM, n keywal <nkeywal@gmail.com> wrote:
>
> > Hi,
> >
> > I would like to direct you to the reference guide, but I must acknowledge
> > that, well, it's a reference guide, hence not really easy for a plain new
> > start.
> > You should have a look at Lars' blog (and may be buy his book), and
> > especially this entry:
> > http://www.larsgeorge.com/2009/10/hbase-architecture-101-storage.html
> >
> > Some hints however:
> > - the replication occurs at the hdfs level, not the hbase level: hbase
> > writes files that are split in hdfs blocks that are replicated accross
> the
> > datanodes. If you want to check the replications, you must look at what
> > files are written by hbase and how they have been split in blocks by hdfs
> > and how these blocks have been replicated. That will be in the hdfs
> > interface. As a side note, it's not the easiest thing to learn when you
> > start :-)
> > - The error > ERROR: org.apache.hadoop.hbase.MasterNotRunningException:
> > Retried 7 times
> >   this is not linked to replication or whatever. It means that second
> > machine cannot find the master. You need to fix this first. (googling &
> > checking the logs).
> >
> >
> > Good luck,
> >
> > Nicolas
> >
> >
> >
> >
> > On Thu, Sep 27, 2012 at 9:07 AM, Venkateswara Rao Dokku <
> > dvrao.584@gmail.com
> > > wrote:
> >
> > > How can we verify that the data(tables) is distributed across the
> > cluster??
> > > Is there a way to confirm it that the data is distributed across all
> the
> > > nodes in the cluster.?
> > >
> > > On Thu, Sep 27, 2012 at 12:26 PM, Venkateswara Rao Dokku <
> > > dvrao.584@gmail.com> wrote:
> > >
> > > > Hi,
> > > >     I am completely new to Hbase. I want to cluster the Hbase on two
> > > > nodes.I installed hadoop,hbase on the two nodes & my conf files are
> as
> > > > given below.
> > > > *cat  conf/regionservers *
> > > > hbase-regionserver1
> > > > hbase-master
> > > > *cat conf/masters *
> > > > hadoop-namenode
> > > > * cat conf/slaves *
> > > > hadoop-datanode1
> > > > *vim conf/hdfs-site.xml *
> > > > <?xml version="1.0"?>
> > > > <?xml-stylesheet type="text/xsl" href="configuration.xsl"?>
> > > >
> > > > <!-- Put site-specific property overrides in this file. -->
> > > >
> > > > <configuration>
> > > > <property>
> > > >         <name>dfs.replication</name>
> > > >         <value>2</value>
> > > >         <description>Default block replication.The actual number
of
> > > > replications can be specified when the file is created. The default
> is
> > > used
> > > > if replication is not specified in create time.
> > > >         </description>
> > > > </property>
> > > > <property>
> > > >         <name>dfs.support.append</name>
> > > >         <value>true</value>
> > > >         <description>Default block replication.The actual number
of
> > > > replications can be specified when the file is created. The default
> is
> > > used
> > > > if replication is not specified in create time.
> > > >         </description>
> > > > </property>
> > > > </configuration>
> > > > *& finally my /etc/hosts file is *
> > > > 127.0.0.1       localhost
> > > > 127.0.0.1       oc-PowerEdge-R610
> > > > 10.2.32.48  hbase-master hadoop-namenode
> > > > 10.240.13.35 hbase-regionserver1  hadoop-datanode1
> > > >  The above files are identical on both of the machines. The following
> > are
> > > > the processes that are running on my m/c's when I ran start scripts
> in
> > > > hadoop as well as hbase
> > > > *hadoop-namenode:*
> > > > HQuorumPeer
> > > > HMaster
> > > > Main
> > > > HRegionServer
> > > > SecondaryNameNode
> > > > Jps
> > > > NameNode
> > > > JobTracker
> > > > *hadoop-datanode1:*
> > > >
> > > > TaskTracker
> > > > Jps
> > > > DataNode
> > > > -- process information unavailable
> > > > Main
> > > > NC
> > > > HRegionServer
> > > >
> > > > I can able to create,list & scan tables on the *hadoop-namenode*
> > machine
> > > > using Hbase shell. But while trying to run the same on the  *
> > > > hadoop-datanode1 *machine I couldn't able to do it as I am getting
> > > > following error.
> > > > hbase(main):001:0> list
> > > > TABLE
> > > >
> > > >
> > > > ERROR: org.apache.hadoop.hbase.MasterNotRunningException: Retried 7
> > times
> > > >
> > > > Here is some help for this command:
> > > > List all tables in hbase. Optional regular expression parameter could
> > > > be used to filter the output. Examples:
> > > >
> > > >   hbase> list
> > > >   hbase> list 'abc.*'
> > > > How can I list,scan the tables that are created by the
> > *hadoop-namenode *
> > > > from the *hadoop-datanode1* machine. Similarly Can I create some
> tables
> > > > on  *hadoop-datanode1 *& can I access them from the *hadoop-namenode
> *
> > &
> > > > vice-versa as the data is distributed as this is a cluster.
> > > >
> > > >
> > > >
> > > > --
> > > > Thanks & Regards,
> > > > Venkateswara Rao Dokku,
> > > > Software Engineer,One Convergence Devices Pvt Ltd.,
> > > > Jubille Hills,Hyderabad.
> > > >
> > > >
> > >
> > >
> > > --
> > > Thanks & Regards,
> > > Venkateswara Rao Dokku,
> > > Software Engineer,One Convergence Devices Pvt Ltd.,
> > > Jubille Hills,Hyderabad.
> > >
> >
>
>
>
> --
> Thanks & Regards,
> Venkateswara Rao Dokku,
> Software Engineer,One Convergence Devices Pvt Ltd.,
> Jubille Hills,Hyderabad.
>

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