[tdwg-guid] Handle System considered not interoperable with standard WWW and SW applications

Markus Döring m.doering at bgbm.org
Wed Jun 6 17:22:03 CEST 2007

Donald, Ricardo,

I fully agree with you and Rod that we need to go forward as fast as  
possible and dont need yet another discussion. If everyone else is  
pleased with LSIDs I will keep silent, promised. LSIDs are better  
than nothing. But if we would use URLs we could go a lot faster  
'cause its so much easier. Especially now after all the lessons learned.

Still some comments below inline

On 06.06.2007, at 16:00, Ricardo Pereira wrote:

> Roderic Page wrote:
>> This all begs the question, is there anything LSIDs give us that  
>> HTTP URIs don't?
> To me, the key difference between plain HTTP URIs and LSIDs with  
> the proxy proposal is that LSIDs name objects with pure identifiers  
> (the capital N in URN), while HTTP URIs mix names with locations.
> If we use the LSID specification with the proxy proposal, the  
> identifier associated permanently with the object is the pure LSID  
> in the form:
>    urn:lsid:authority.org:namespace:objectId
> which is completely independent of transfer protocol and thus may  
> remain associated with the object for hundreds of years. If HTTP or  
> DNS or whatever goes away, our grandchildren can still rebuild the  
> links between ids and objects using whatever technologies are  
> available in year 2207. More importantly, such a hypothetical new  
> solution would likely be elegant because that particular URN was  
> solely designed to name objects.
How does LSID resolution work without DNS? If the DNS-less LSID is  
just about persistent global *naming* and not *resolution*, then we  
can use UUIDs and be happy

> On the other hand, if we use HTTP URIs and that eventually goes  
> away, we would need to come up with a hack to keep the ids  
> associated with the objects. Also, HTTP URIs were originally  
> designed to locate resources (the last T on HTTP), not to name  
> them. So, in my opinion, using HTTP to name objects is a bit of a  
> hack (i.e. not very elegant). You end up trying to dereference IDs  
> that were not meant to be dereferenced, which only contribute to  
> link rot.
> Another point is in relation to link rot. Although the article  
> "Cool URIs Don't Change" provides very useful ideas about how to  
> make HTTP URIs permanent (which I literally use on every link on  
> the TDWG website), they don't completely solve the link rot  
> problem. We still have to deal with reorganizations in our web  
> servers and managing a stack of Apache rewrite rules is no fun.
> LSIDs on the other hand solve part of the problem, at least those  
> associated with path portion of the HTTP URI. LSIDs however present  
> the same persistence problems associated with DNS. To reduce that  
> problem, TDWG offers DNS entries of the form *.lsid.tdwg.org for  
> LSID authorities in our domain.

I can't see any big difference between LSID based redirection and  
http redirection a la PURL. What makes LSIDs easier to maintain for  
the final provider?

> So, in my opinion, these are strong reasons not to use only HTTP  
> URIs to name our objects.
> Cheers,
> Ricardo
>> If we go to all this trouble to make LSIDs behave as if they were  
>> HTTP URIs, isn't this tell us something...?
>> Regards
>> Rod
>> On 6 Jun 2007, at 14:13, Ricardo Pereira wrote:
>>> Roderic Page wrote:
>>>> Ricardo,
>>>> I think your arguments pretty much apply to LSIDs as well. By  
>>>> themselves, they don't play ball with the WWW or the Semantic Web.
>>>> For LSIDs we need a proxy that understands SOAP, can talk to the  
>>>> DNS, read WSDL files, and then do an HTTP look-up. You only get  
>>>> LSIDs to play ball by using a proxy that plays ball.
>>> I agree. That's why we are putting forward the LSID HTTP proxy  
>>> recommendations (http://wiki.tdwg.org/twiki/bin/view/GUID/ 
>>> LsidHttpProxyUsageRecommendation). And there will be at least one  
>>> LSID proxy (that at http://lsid.tdwg.org/) that will play ball  
>>> pretty soon. That proxy all that you said, just doesn't perform  
>>> the content-negotiation bit yet. But I'm currently working on that.
>>>> In principle we can do the same sort of thing for Handles (there  
>>>> is code for a proxy servlet at http://www.handle.net/ 
>>>> proxy_servlet.html).
>>> Only if handle types fully matched the standard WWW content  
>>> types. They could match if we defined handle types for our own  
>>> community, but they won't ever match with the types defined by  
>>> other communities like DOI and others using Handles.
>>> On the other hand, LSID spec allows us to implement standard  
>>> content negotiation seamlessly because the semantics of the  
>>> argument *accepted_formats* in the LSID getMetadata call is  
>>> appropriate for that purpose.
>>>> I'm not necessarily defending Handles, but I think our choice  
>>>> needs to be well-informed. I still don't think the case for  
>>>> LSIDs has really been made (or, at least, some of the arguments  
>>>> advanced in favour of LSIDs apply equally well, if not better,  
>>>> to other technologies).
>>> I agree with you on this. The case for LSIDs wasn't strong enough  
>>> because the original proposal doesn't integrate well with HTTP.  
>>> That is exactly why we are putting forward the LSID HTTP proxy  
>>> proposal. It was the missing point in the LSID case.
>>> In any case, I suppose we will talk more about this in the near  
>>> future.
>>> Cheers,
>>> Ricardo
>>> _______________________________________________
>>> tdwg-guid mailing list
>>> tdwg-guid at lists.tdwg.org
>>> http://lists.tdwg.org/mailman/listinfo/tdwg-guid
>> --------------------------------------------------------------------- 
>> -------------------------------------------
>> Professor Roderic D. M. Page
>> Editor, Systematic Biology
>> Graham Kerr Building
>> University of Glasgow
>> Glasgow G12 8QP
>> United Kingdom
>> Phone:    +44 141 330 4778
>> Fax:      +44 141 330 2792
>> email:    r.page at bio.gla.ac.uk
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