[Architecture] Having UUIDs for a resource

[Samisa Abeysinghe]

On Tue, Mar 29, 2011 at 8:34 AM, Sanjiva Weerawarana <sanjiva at wso2.com>wrote:

> How will we define "same" .. are two versions going to have the same UUID
> or different UUIDs? Is the user going to be able to set the UUID or at least
> give instructions when to re-use a UUID of another resource? If I copy a
> resource to another place do we retain the same UUID?


To ask the same questions in a different manner, would a resource change if
we:

   1. create a new version
   2. re-use a resource
   3. copy a resource

If yes, the the UUID should change, else it should not.


>
> If we do intro this concept then we should also have a way to get to
> resources via this directly - something like /uuid/FDJHJHGDSFSSHFSNFSFSN to
> get that resource directly. I think we discussed something similar in the
> UDDI context right?
>
> It almost feels to me like we should create an ETag [1] based on the
> resource content and make that be the UUID. That way we can ignore the path
> too just like with a UUID.
>
> Sanjiva.
> [1] http://en.wikipedia.org/wiki/HTTP_ETag
>
> On Sun, Mar 27, 2011 at 9:47 PM, Senaka Fernando <senaka at wso2.com> wrote:
>
>> Hi Hiranya,
>>
>> On Sun, Mar 27, 2011 at 11:47 AM, Hiranya Jayathilaka <hiranya at wso2.com>wrote:
>>
>>> Looks like a useful thing. Are we going to provide any special support
>>> for this feature in the UI?
>>
>>
>> We have not yet thought about the UI-level improvements around this.
>> Currently this is a concept that lives at API-level. The UI might need these
>> improvements in some form someday.
>>
>> Thanks,
>> Senaka.
>>
>>>
>>> Thanks,
>>> Hiranya
>>>
>>> On Sun, Mar 27, 2011 at 2:01 AM, Senaka Fernando <senaka at wso2.com>wrote:
>>>
>>>> Hi all,
>>>>
>>>> Resources added to our repository can be moved from one location to
>>>> another, or checked-out and checked-in to another repository. However, there
>>>> might be applications which need to be able to uniquely identify a resource
>>>> despite the change in the location where it has been stored (rename or
>>>> move). For example, you might add a PDF document into location /foo/bar, and
>>>> then move it to /foo/foobar/bar sometime later. There should be someway to
>>>> identify that it is the same PDF that exists in this new location.
>>>>
>>>> This is somewhat like a tag, but a tag is a more generic concept (and
>>>> more than one resource can have the same tag). Also, the same UUID should be
>>>> used, whenever this particular resource needs to be uniquely identified
>>>> (i.e. there should not be two unique identifiers stored against the same
>>>> resource). So, for example, a WS-Eventing subscription id, should be equal
>>>> to the UUID of the resource which is used to store that subscription.
>>>>
>>>> And, interestingly, this concept can change from application to
>>>> application. In other words, copies of a single resource might carry the
>>>> same UUID or might carry different UUIDs. Similarly, irrespective of the
>>>> behaviour during a copy operation, when a resource is checked-out and
>>>> checked-in to a new repository, you might want the UUID to be carried to the
>>>> new repository.
>>>>
>>>> Given the requirements, this can be facilitated using a handler (so that
>>>> the concept can be disabled/customized depending on its application), along
>>>> with a standard property name (a constant defined in RegistryConstants), so
>>>> that components like eventing, can make use of this concept if it has been
>>>> enabled.
>>>>
>>>> WDYT?
>>>>
>>>> Thanks,
>>>> Senaka.
>>>>
>>>> --
>>>> *Senaka Fernando*
>>>> Product Manager - WSO2 Governance Registry;
>>>> Associate Technical Lead; WSO2, Inc.; http://wso2.com*
>>>> Member; Apache Software Foundation; http://apache.org
>>>>
>>>> E-mail: senaka AT wso2.com
>>>> **P: +1 408 754 7388; ext: 51736*; *M: +94 77 322 1818
>>>> Linked-In: http://www.linkedin.com/in/senakafernando
>>>>
>>>> *Lean . Enterprise . Middleware
>>>>
>>>>
>>>> _______________________________________________
>>>> Architecture mailing list
>>>> Architecture at wso2.org
>>>> https://mail.wso2.org/cgi-bin/mailman/listinfo/architecture
>>>>
>>>>
>>>
>>>
>>> --
>>> Hiranya Jayathilaka
>>> Senior Software Engineer;
>>> WSO2 Inc.;  http://wso2.org
>>> E-mail: hiranya at wso2.com;  Mobile: +94 77 633 3491
>>> Blog: http://techfeast-hiranya.blogspot.com
>>>
>>
>>
>>
>> --
>> *Senaka Fernando*
>> Product Manager - WSO2 Governance Registry;
>> Associate Technical Lead; WSO2, Inc.; http://wso2.com*
>> Member; Apache Software Foundation; http://apache.org
>>
>> E-mail: senaka AT wso2.com
>> **P: +1 408 754 7388; ext: 51736*; *M: +94 77 322 1818
>> Linked-In: http://www.linkedin.com/in/senakafernando
>>
>> *Lean . Enterprise . Middleware
>>
>>
>> _______________________________________________
>> Architecture mailing list
>> Architecture at wso2.org
>> https://mail.wso2.org/cgi-bin/mailman/listinfo/architecture
>>
>>
>
>
> --
> Sanjiva Weerawarana, Ph.D.
> Founder, Chairman & CEO; WSO2, Inc.;  http://wso2.com/
> email: sanjiva at wso2.com; phone: +94 11 763 9614; cell: +94 77 787 6880 |
> +1 650 265 8311
> blog: http://sanjiva.weerawarana.org/
>
> Lean . Enterprise . Middleware
>
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> Architecture mailing list
> Architecture at wso2.org
> https://mail.wso2.org/cgi-bin/mailman/listinfo/architecture
>
> Thanks,
Samisa...

Samisa Abeysinghe
VP Engineering
WSO2 Inc.
http://wso2.com
http://wso2.org
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