Re: [Storagesync] Storagesync Digest, Vol 5, Issue 1

Markus Unterwaditzer <markus@unterwaditzer.net> Sun, 06 December 2015 17:36 UTC

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Date: Sun, 06 Dec 2015 18:36:46 +0100
From: Markus Unterwaditzer <markus@unterwaditzer.net>
To: Linhui Sun <lh.sunlinh@gmail.com>
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Cc: storagesync <storagesync@ietf.org>, Ted Lemon <mellon@fugue.com>
Subject: Re: [Storagesync] Storagesync Digest, Vol 5, Issue 1
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> IMO, etag is designed for client side cache. A typical usage: if the file
> on the server has no actual change, the client will use the cache and the
> server does not need to send the file content again. While for a storage
> service, we also need some some similar mechanism at server side. In this
> way, the client do not need to upload unchanged content to the server.

There is no "true-and-only" usecase for etags, and no, you do not need anything
more than etags for synchronization. Using a additional "metadata" file, the
client can cheaply determine whether local content changed and whether server
content changed, and that's all that is required for (in this case) file
synchronization. Sync conflicts are a different story, and the solution to that
heavily depends on the kind of data you're syncing.

> 
> > --
> > Sent from my phone. Please excuse my brevity.
> >
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