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Posted to hdfs-user@hadoop.apache.org by Harold Lim <ro...@yahoo.com> on 2009/09/15 22:55:57 UTC

Question about decommissioning a node

Hi All,

Is there a document or can anyone explain to me what actually happens during the decommissioning process? What does the name node do?
Also, how much bandwidth does the decommissioning process take? Is there a cap to the maximum bandwidth consumed?


Thanks,
Harold

Re: Question about decommissioning a node

Posted by Dhruba Borthakur <dh...@gmail.com>.

>s the source of transfers always the node being decommissioned?

No. the source of the transfer(s) could be any other node in the cluster.

dhruba


On Wed, Sep 16, 2009 at 10:06 AM, Harold Lim <ro...@yahoo.com> wrote:

> Thanks.
>
> Another Question: During decommissioning process, does HDFS strictly copy
> blocks/files from the decommissioned node to the other live nodes? Or do
> blocks get copied from other live nodes too?
>
> i.e., is the source of transfers always the node being decommissioned?
>
> -Harold
>
> --- On Tue, 9/15/09, Dhruba Borthakur <dh...@gmail.com> wrote:
>
> > From: Dhruba Borthakur <dh...@gmail.com>
> > Subject: Re: Question about decommissioning a node
> > To: hdfs-user@hadoop.apache.org
> > Date: Tuesday, September 15, 2009, 5:03 PM
> > This might help:
> >
> > http://wiki.apache.org/hadoop/FAQ#17
> > https://issues.apache.org/jira/browse/HADOOP-681
> >
> >
> > Bandwidth can be throttled on a  datanode via
> > dfs.balance.bandwidthPerSec
> >
> > thanks,
> > dhruba
> >
> >
> > On Tue, Sep 15, 2009 at 1:55 PM,
> > Harold Lim <ro...@yahoo.com>
> > wrote:
> >
> > Hi All,
> >
> >
> >
> > Is there a document or can anyone explain to me what
> > actually happens during the decommissioning process? What
> > does the name node do?
> >
> > Also, how much bandwidth does the decommissioning process
> > take? Is there a cap to the maximum bandwidth consumed?
> >
> >
> >
> >
> >
> > Thanks,
> >
> > Harold
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
>
>
>
>

Re: Question about decommissioning a node

Posted by Harold Lim <ro...@yahoo.com>.

Thanks.

Another Question: During decommissioning process, does HDFS strictly copy blocks/files from the decommissioned node to the other live nodes? Or do blocks get copied from other live nodes too?

i.e., is the source of transfers always the node being decommissioned?

-Harold

--- On Tue, 9/15/09, Dhruba Borthakur <dh...@gmail.com> wrote:

> From: Dhruba Borthakur <dh...@gmail.com>
> Subject: Re: Question about decommissioning a node
> To: hdfs-user@hadoop.apache.org
> Date: Tuesday, September 15, 2009, 5:03 PM
> This might help:
> 
> http://wiki.apache.org/hadoop/FAQ#17
> https://issues.apache.org/jira/browse/HADOOP-681
> 
> 
> Bandwidth can be throttled on a  datanode via
> dfs.balance.bandwidthPerSec
> 
> thanks,
> dhruba
> 
> 
> On Tue, Sep 15, 2009 at 1:55 PM,
> Harold Lim <ro...@yahoo.com>
> wrote:
> 
> Hi All,
> 
> 
> 
> Is there a document or can anyone explain to me what
> actually happens during the decommissioning process? What
> does the name node do?
> 
> Also, how much bandwidth does the decommissioning process
> take? Is there a cap to the maximum bandwidth consumed?
> 
> 
> 
> 
> 
> Thanks,
> 
> Harold
> 
> 
> 
> 
> 
> 
> 
> 
> 
>

Re: Question about decommissioning a node

Posted by Dhruba Borthakur <dh...@gmail.com>.

This might help:

http://wiki.apache.org/hadoop/FAQ#17
https://issues.apache.org/jira/browse/HADOOP-681

Bandwidth can be throttled on a  datanode via dfs.balance.bandwidthPerSec

thanks,
dhruba


On Tue, Sep 15, 2009 at 1:55 PM, Harold Lim <ro...@yahoo.com> wrote:

> Hi All,
>
> Is there a document or can anyone explain to me what actually happens
> during the decommissioning process? What does the name node do?
> Also, how much bandwidth does the decommissioning process take? Is there a
> cap to the maximum bandwidth consumed?
>
>
> Thanks,
> Harold
>
>
>
>