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From "Ahmad Humayun" <ahmad.hu...@gmail.com>
Subject Re: deleting files from the DFS
Date Wed, 12 Mar 2008 18:00:49 GMT
So does that mean nodes can possibly read files that have been "deleted"

thanks :)


regards,

On Wed, Mar 12, 2008 at 10:57 PM, Hairong Kuang <hairong@yahoo-inc.com>
wrote:

> > Case 1: Lets say there is a node which opens a file on the DFS to read.
> From
> > my understanding, the open request will go to the namenode, which will
> tell
> > it where the blocks of the file are. What if another node comes up and
> asks
> > to delete that file. Of course this request will go to the namenode. How
> > will the namenode respond in such a situation?
> >
>
> The namenode is stateless. So the delete request will go through. The
> first
> request may fail.
>
> > Case 2: Whenever a node wants to delete a file, I think the request
> first
> > lands with the namenode? What happens to the replicas of the blocks of
> that
> > file, as soon as that file gets deleted?
> >
>
> The replicas are scheduled to be deleted by the namenode. But there may be
> some delay before they are actually deleted on the datanodes.
>
> Hairong
>
>


-- 
Ahmad Humayun
Research Assistant
Computer Science Dpt., LUMS
+92 321 4457315

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