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From sulabh choudhury <sula...@gmail.com>
Subject Re: Checkpoint vs Backup Node
Date Wed, 25 May 2011 20:51:07 GMT
Thanks for the response.
Well the hanging of BN and its consequences seem to be a scary situation.
So when using a CN, in case of a NN failure...we would loose the edits after
the last checkpoint, but it seems to be a decent trade-off for the stability
which the Backup Node might lack.


On Tue, May 24, 2011 at 6:12 PM, Todd Lipcon <todd@cloudera.com> wrote:

> Hi Sulabh,
>
> Neither of these nodes have been "productionized" -- so I don't think
> anyone would have a good answer for you about what works in
> production. They are only available in 0.21 and haven't had any
> substantial QA.
>
> One of the potential issues with the BN is that it can delay the
> logging of edits by the primary NN, if the BN were to hang or go
> offline. The CN would not have such an issue.
>
> -Todd
>
> On Tue, May 24, 2011 at 5:08 PM, sulabh choudhury <sulabhc@gmail.com>
> wrote:
> > As far as my understanding goes, I feel that Backup node is much more
> > efficient then the Checkpoint node, as it has the current(up-to-date)
> copy
> > of file system too.
> > I do not understand what would be the use case (in a production
> environment)
> > tin which someone would prefer Checkpoint node over Backup node, or I
> should
> > ask, what do people generally prefer of the two and why ?
> >
>
>
>
> --
> Todd Lipcon
> Software Engineer, Cloudera
>

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