Hello all,

I am not getting the clear way out to remove datanode from the cluster.

please explain me decommissioning steps with example.  

like how to creating exclude files and other steps involved in it.

Thanks & regards

Yogesh Kumar    

Hi Yogesh

The detailed steps are available in hadoop wiki on FAQ page

http://wiki.apache.org/hadoop/FAQ#I_want_to_make_a_large_cluster_smaller_by_taking_out_a_bunch_of_nodes_simultaneously._How_can_this_be_done.3F

Regrads
Bejoy KS

On Wed, Sep 12, 2012 at 12:14 AM, yogesh dhari <[EMAIL PROTECTED]> wrote:

>  Hello all,
>
> I am not getting the clear way out to remove datanode from the cluster.
>
> please explain me decommissioning steps with example.
> like how to creating exclude files and other steps involved in it.
>
>
> Thanks & regards
> Yogesh Kumar
>

hi yogesh,

Hope this helps

To remove nodes from the cluster:
1. Add the network addresses of the nodes to be decommissioned to the
exclude file. Do not update the include file at this point.
2. Update the namenode with the new set of permitted datanodes, with
this command:
% hadoop dfsadmin -refreshNodes
3. Update the jobtracker with the new set of permitted tasktrackers using:
% hadoop mradmin -refreshNodes
4. Go to the web UI and check whether the admin state has changed to
“Decommis- sion In Progress” for the datanodes being decommissioned.
They will start copying their blocks to other datanodes in the
cluster.
5. Whenallthedatanodesreporttheirstateas“Decommissioned,”thenalltheblocks
have been replicated. Shut down the decommissioned nodes.
6. Remove the nodes from the include file, and run:
% hadoop dfsadmin -refreshNodes
% hadoop mradmin -refreshNodes
7. Remove the nodes from the slaves file.

Regards
Abhi

On Tue, Sep 11, 2012 at 2:44 PM, yogesh dhari <[EMAIL PROTECTED]> wrote:
> Hello all,
>
> I am not getting the clear way out to remove datanode from the cluster.
>
> please explain me decommissioning steps with example.
> like how to creating exclude files and other steps involved in it.
>
>
> Thanks & regards
> Yogesh Kumar