Re: Z39.50 - what I've learned

Hi!  Stephen wrote:

>Hi all,
>
>As you may know I've been trying to learn all about Z39.50 and how to
>implement it on my existing library system.
>
>Here is what I've learned. Please correct any mistakes.
>...

>This seems a bit like overkill to me because the Z39.50 client, the server
>and the database could all be sitting on the same machine (the web server),
>but if that's what's required to be compliant then so be it.

Yes, they could all be on the same machine, or they could each be located on
a different continent.  If you are ONLY concerned with the 1-machine
scenario then I suggest that Z39.50 is irrelevant to your situation.  The
advantage of Z39.50 compliance comes in when many diverse clients can all
access your server and your client can access multiple diverse servers.

>Would anyone argue that a web form on a web page is actually the client, and
>that the CGI app. is the server?

No.

>3. This raises other issues if what I say is correct. I need to allow my
>library data to be searchable by other Z39.50 clients. I'm guessing but
>there is probably no standard format for Z39.50 web forms, so that could be
>a problem. Comments?

Other clients would contact your server directly, not go through your form
or cgi script.

>4. People have mentioned that I need to write something that will listen on
>a port (typically 210 or 2100) accept Z39.50 requests and respond with
>information from your database. This would be the Z39.50 server application
>that would be listening, right? 

Yes.

>They will be listening for action from the
>Z39.50 client, which in this case is the CGI app. Is that right?

The server will be listening for action from ANY Z39.50 client, which in
this case could be your CGI app. or Sebastian's CGI app. or BookWhere or
something else entirely.  Once you publicize your Z39.50 server it is
relatively trivial for any Z39.50 user on the planet to target your server
with their own preferred client.  (You can of course limit this with various
security measures if you so desire.) Your Web form may be configured to
search your database(s) using your CGI app. while I set up a Web form using
the ZAP CGI app. to search several databases including yours that have some
connection that makes sense to me, like "British History libraries, museums
and archives" or "libraries within an 4-hour drive of my house" or whatever.
These Web forms make it easy for the Z39.50-ignorant to discover desired
information resources from any Web browser on the Internet.

>5. I may also develop a desktop application for staff at the colleges to
>use. The web interface would primarily be for students and people wanting to
>access the library data outside of the college. So the desktop app. would
>communicate with the Z39.50 server in the same way as the Z39.50 CGI. app.
>The desktop will be more powerful and do much more than is possible from a
>web browser.

In an internal closed-loop system like this you might want to design your
desktop app. to work directly with your back-end database using SQL or some
such.  Again, Z39.50 becomes relevant when you go outside the closed-loop
system.

I hope that this has been helpful, and I'm sure that other list members will
correct me if I have made any errors.


Kevin C. Marsh, Executive Director
Information Access Institute
KMarsh@Information.org     http://Information.org

Received on Wednesday, 13 June 2001 13:28:44 UTC