Delivery-Date: Thu Nov 20 14:04:19 2008
Message-Id: <200811202201.mAKM1flx023598@bourbon.usc.edu>
To: cs551@merlot.usc.edu
Subject: Re: Doubt in Get Request
Date: Thu, 20 Nov 2008 14:01:41 -0800
From: Bill Cheng <william@bourbon.usc.edu>

Someone wrote:

  > So, suppose we have a copy in the files directory as 0.meta and 0.data, and
  > we request for a copy of the same file from another node, we flood the Get
  > Request and actually get the file from another node.
  > 
  > So, now we have another copy as 1.data and 1.meta right?, also all our index
  > structures will have 2 entries for the same file copies, isnt it?
  > 
  > Or, are we supposed to just maintain one copy and delete 1.meta and 1.data?

The rule is that you must not store two files with the same
FileName, SHA1, *and* Nonce in your node, no matter what!

  > I think, the case should be similar to the one, where we do a GET for the
  > same fileID twice. Are we supposed to keep both 0.* and 1.* ?
  > 
  > Also for cached files, if we already have cached a file , we should not
  > cache it again, even if it passes through once many times. right?

You should apply the same rule as above.
--
Bill Cheng // bill.cheng@usc.edu <URL:http://merlot.usc.edu/william/usc/>


  On Thu, Nov 20, 2008 at 1:28 PM, Bill Cheng <william@bourbon.usc.edu> wrote:
  > Someone wrote:
  >
  >  > We had a doubt regarding the Get command:
  >  > Suppose, In a get request, we request for a file on another node. But, a
  >  > copy of the same file(Filename, sha1, Nonce) exists on the current node.
  >  > Then, should we just copy the local file, or do we have to flood a get
  >  > request, so that the file becomes popular??
  >
  > You must flood a GET message in this case for the reason you stated.
  > --
  > Bill Cheng // bill.cheng@usc.edu <URL:http://merlot.usc.edu/william/usc/>