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From Michael Segel <michael_se...@hotmail.com>
Subject Re: Question about Name Spaces…
Date Wed, 15 May 2013 22:19:29 GMT
Actually creating links, symbolic or hard links makes sense in a couple of scenarios. 
Especially in terms of hive... ;-) 

So it kind of goes back to my extension of the question about that Jira (HDFS-3370) to see
if its alive or just forgotten? 

The point is that one of the arguments against doing it didn't make sense. Creating hard links
across Name Spaces.
IMHO you'd want to create hard links within the same NN. Maybe a symbolic link across name
spaces, but even then, I'm not so sure... still need to think more about the problem.

On May 15, 2013, at 1:30 PM, Harsh J <harsh@cloudera.com> wrote:

> Namespace divides are designed with application-level separation in
> mind. Sharing a file across namespaces does not make a whole lot of
> sense to me.
> 
> Anyhow, the data is on the same set of DNs, and there's HA for NN's
> own availability (if thats really a concern), so I don't see why
> anyone would like to _maintain_ two synced copies of files as thats
> just data duplication when all you need is a simple path (viewfs)/URI
> (hdfs) to access a file lying on a different NN.
> 
> The reason you mention of metadata availability doesn't sound logical
> - in such a case a person has to build a self failover of URIs for
> said file, which they can simply avoid by using HDFS HA for the
> hosting NN.
> 
> On Wed, May 15, 2013 at 7:47 PM, Michael Segel
> <michael_segel@hotmail.com> wrote:
>> Quick question...
>> So when we have a cluster which has multiple namespaces (multiple name nodes) , why
would you have a file in two different namespaces?
>> 
>> 
> 
> 
> 
> -- 
> Harsh J
> 


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