W3C home > Mailing lists > Public > ietf-dav-versioning@w3.org > July to September 2001

Re: Versions being deleted during a MERGE...

From: Peter Raymond <Peter.Raymond@merant.com>
Date: Mon, 20 Aug 2001 20:19:55 +0100
Message-ID: <3B8162DA.39C8D357@merant.com>
To: "Clemm, Geoff" <gclemm@rational.com>
CC: ietf-dav-versioning@w3.org
Hi,

"Clemm, Geoff" wrote:

> A server is of course free to refuse the DELETE request,
> and indicate as its reason that it didn't want to satisfy
> the postcondition that would remove that version URL from
> the DAV:merge-set.
>

I thought the servers (to be compliant) MUST enforce the postconditions.
Are you saying a deltav compliant server needs not honour all the
postconditions?  If servers do not honour the postconditions would it not
lead to possible non-interoperability?

>
> Note thought that even if the server allows the deletion,
> there is no race condition here, though,
> just some dangling version URL's that will return 404's
> when accessed.
>

The condition I was thinking of was when client A issues the MERGE request
(which checks-out the VCR) but after getting the HTTP response for the
query for
the checked-out resources DAV:merge-set client B deletes one of the
versions
referenced in that set.  Client A then goes on to do a GET (for example) to
retrieve
the content to be merged but it would fail (with a 404).....client B's
DELETE got there
first!

I guess I would implement Tims idea and lock down all the resources before
beginning the interactive merge.

Also I just noticed that in section 11.2 we define merged-set, updated-set,

and ignored-set but the example in section 11.2.1 has <D:update-set> etc
not <D:updated-set> etc.


Regards,
Peter Raymond - MERANT.

>
> Cheers,
> Geoff
>
> -----Original Message-----
> From: Peter Raymond [mailto:Peter.Raymond@merant.com]
> Sent: Sunday, August 19, 2001 8:22 AM
> To: ietf-dav-versioning@w3.org
> Subject: Versions being deleted during a MERGE...
>
> Hi,
>
> I just noticed a potential problem with versions being used for a merge
> operation
> being deleted during the merge.
>
> Section 11 says a checked-out resource has a DAV:merge-set identifying
> versions
> to be merged.  DELETE (section 11.5) says it will remove entries from
> the
> merge-set.  Shouldn't the server disallow the DELETE, someone somewhere
> is in the
> middle of a merge using this version, also there would be a race
> condition if someone
> deletes the version while the client is processing the DAV:merge-set of
> a checked-out
> resource.
>
> Regards,
> Peter Raymond - MERANT
Received on Monday, 20 August 2001 15:21:41 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Tuesday, 8 January 2008 13:57:42 GMT