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Re: [Handle-info] Re: Please help me understand the value of Handle


Things are getting a little confusing. Hopefully I can help and not make it worse...

Steve:
Your *handle* server is located by its IP address, not its domain name. That IP address is registered with the root/global handle service by sending in your sitebndl.zip and/or siteinfo.bin file. If the domain name of your handle server changes, no problem. If the IP address changes then you need to update your siteinfo.bin file and re- submit it. The easy way to do this is to re-run the setup process.

Also, please note that if your handle server has an address such as 192.168.* (ie on a private network) then it will not be accessible by any handle clients outside of your organization, including the http:// hdl.handle.net http-to-hdl proxy/gateway which is how most handles are resolved nowadays.



Tim:
I would advise against creating your own customized proxy, at least for the reason described. If your handles are not resolvable by native handle resolvers (ie browser plugins, the hdl.handle.net proxy, etc) then they will break when someone tries to access them in any way except for through your proxy. In this situation your handles are no longer useful unless they are accessed through http:// hdl.coalliance.org/ which means that the handle server is really only serving as a local database for an HTTP redirector.

Wouldn't it be better if your handle identifiers can be resolved from anywhere in order to access the resource to which they refer?

In general if the URL for a document that has been assigned a handle changes, then you should update the handle to point to the new location. This is the indirection service that the handle system provides - you keep the same handle but the document can move to wherever you like. If you move all of your documents from one domain to another then a (batch) change of the handles for those documents is the proper way to keep things consistent.

Cheers,
Sean

On Mar 23, 2007, at 4:19 PM, Steve wrote:

I want to chime in, for fear that I am confused.

The way I understand it, When a server changes from shield to dagger or anything else for that matter is it not just a simple matter of rebuilding the sitebndl file sending it to CNRI for processing or am I missing something?

Tim Donnelly wrote:

This is intriguing to me. Let me see if I understand this correctly.

If I host my own proxy, and customize it as you suggest, so that the domain (http://shield.mydomain.com <http://shield.mydomain.com/ >) is part of the handle name space, I can then create my Handle so that the URL only contains the final destination (todo.txt). This way, if shield ever changes to dagger I only have to update the information in the proxy server.

I think I just rehashed exactly what you wrote, but I want to be clear on this. If this is correct, it is almost exactly what we had envisioned the Handle system to be.

Thanks again


Tim Donnelly
Systems/Network Administrator
Colorado Alliance of Research Libraries
(303)759-3399 x106

*On Fri Mar 23 7:38 , Giridhar Manepalli sent:

*

    Tim,
    Adding to what Larry Lannom has already mentioned:
    Handle Sytem provides advanced capabilities to be used by service
    providers that provide a low entry barrier for the clients to use
    these
    capabilities efficiently.

Coming back to your particular case: I would recommend you to
slightly
customize the handle proxy software. Handle proxy software is the one
that is deployed in various locations and people use them by calling
hdl.handle.net.

You may very well deploy your own proxy server (let's say
hdl.coalliance.org) with slight customization. The customization is
necessary to allow the root domain of the your web server
(http://shield.mydomain.org/
<parse.pl?redirect=http%3A%2F%2Fshield.mydomain.org%2F>

    ) be part
    of your handle namespace.
    The handles can now have todo.txt as part of the URL handle
    record. (for
    example, in the handle 98765/todo).

Now, as a result of the customization at the proxy level - you could
access http://hdl.coalliance.org/98765/todo
<parse.pl?redirect=http%3A%2F%2Fhdl.coalliance.org%2F98765% 2Ftodo>
and that would resolve to
http://shield.mydomain.org/
<parse.pl?redirect=http%3A%2F%2Fshield.mydomain.org%2F>
todo.txt

If the root domain of your webserver changes - this would require
you to
just change a single configuration at the proxy level. This would
relieve you from using a batch process to update all the handles (and
even before, documenting what those handles are).

Based on your use case and requirement, you may pursue either of the
options (proxy customization or batch update process) - we are
glad to
guide you in either of your efforts, if need may be.


    Thanks,
    Giridhar

Tim Donnelly wrote:

> OK, that makes some sense. I assume then that if I have 1 million
> handles (which is not outside the relm of possiblity for the
project)
> that I can use a batch process to update all of those if, for some
> reason, it becomes necessary?
>
> While it's not excatly what we were thinking, I can see that
there is
> some value added by the Handle System.
>
> Thanks for all the replies.
>
> Tim Donnelly
> Systems/Network Administrator
> Colorado Alliance of Research Libraries
> (303)759-3399 x106
>
> *On Fri Mar 23 6:10 , handle-info-request@cnri.reston.va.us
<javascript:top.opencompose('handle-info- request@cnri.reston.va.us','','','')>
sent:
> *
>
>
> Message: 2
> To: handle-info@cnri.reston.va.us
<javascript:top.opencompose('handle- info@cnri.reston.va.us','','','')>
> handle-info@cnri.reston.va.us
<javascript:top.opencompose('handle- info@cnri.reston.va.us','','','')>','','','')>
> Subject: Re: [Handle-info] Please help me understand the value of
> Handle
> From: Michael Judd <
<javascript:top.opencompose('handle- info@cnri.reston.va.us','','','')>m.judd@griffith.edu.au
<javascript:top.opencompose('m.judd@griffith.edu.au','','','')>
> m.judd@griffith.edu.au
<javascript:top.opencompose('m.judd@griffith.edu.au','','','') >','','','')>>
> Date: Fri, 23 Mar 2007 10:04:48 +1000
>
> This is a multipart message in MIME format.
> --=_alternative 000044514A2572A7_=
> Content-Type: text/plain; charset="US-ASCII"
>
> Hi Tim,
> I'm no handle expert but here goes...
> Handles are just updatable mappings to URLs.
> They allow you to publish URLs to documents that, as long as you
> maintain
> the mapping, will always resolve.
> So in your example, originally you might have given the URL
> <javascript:top.opencompose ('m.judd@griffith.edu.au','','','')>http://hdl.handle.net/98765/todo
<http://webmail.coalliance.org/parse.pl?redirect=http%3A%2F% 2Fhdl.handle.net%2F98765%2Ftodo>
> to
> someone so that they could see the
> document at http://shield.mydomain.org/todo.txt
<http://webmail.coalliance.org/parse.pl?redirect=http%3A%2F% 2Fshield.mydomain.org%2Ftodo.txt>
> .
> (Any handle server should be able to resolve any handle, but since
> handle
> servers themselves are suseptable to hostname changes etc. you
> should use
> the cnri handle server (hdl.handle.net) when giving out handle
> URLs as it
> is guaranteed not to change.)
> Back to your example, after your hostname change you would update
> 98765/todo to point to http://dagger.mydomain.org/todo.txt
<http://webmail.coalliance.org/parse.pl?redirect=http%3A%2F% 2Fdagger.mydomain.org%2Ftodo.txt>
> so
> that
> everyone who went to http://hdl.handle.net/98765/todo
<http://webmail.coalliance.org/parse.pl?redirect=http%3A%2F% 2Fhdl.handle.net%2F98765%2Ftodo>
>
> would continue to
> see the correct document.
> Originally you may have had another document at http://
> whatever.mydomain.org/whatever.txt that you created the handle
> http://hdl.handle.net/98765/whatever
<http://webmail.coalliance.org/parse.pl?redirect=http%3A%2F% 2Fhdl.handle.net%2F98765%2Fwhatever>
>
> for. This handle will still be valid
> as long as http://whatever.mydomain.org/whatever.txt
<http://webmail.coalliance.org/parse.pl?redirect=http%3A%2F% 2Fwhatever.mydomain.org%2Fwhatever.txt>
>
> points to the
> document.
> Handles with the same prefix (98765) don't have to resolve to the
> same
> server. The prefix is just used to locate the actual handle server.
> Using DNS cnames and aliases you can keep URLs that simply move
> servers or
> change hostnames resolving. But what happens if an organizations
> domain
> name changes? Or what happens if the repository software the
> documents
> exist in changes, and all the relative links change? This is where
> the
> value of handles and other persistant URL schemes come.
> That's how I see it anyway. :)
> Cheers!
>
> Regards,
>
> Michael Judd
>
> Nathan Campus, Griffith University.
> Brisbane 4111. Australia.
>
> m.judd@griffith.edu.au
<javascript:top.opencompose('m.judd@griffith.edu.au','','','')>
> m.judd@griffith.edu.au
<javascript:top.opencompose('m.judd@griffith.edu.au','','','') >','','','')>
> 07 3735 3801
>
>
>
>
>
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--
Steve DiSorbo
System Programmer
Yale University ITS, AM&T Library Systems
Voice (203) 432-6694
Fax   (203) 436-4067
steve.disorbo@yale.edu
http://www.library.yale.edu/


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