[Koha-zebra] [Fwd from koha-devel]: Worries about zebra

[Sebastian Hammer]

Hi All,

I work at Index Data, and I know something about what Zebra can and can't 
do.. and perhaps of the pros and cons of different ways of approaching the 
task of integrating it into an application. I hope it's OK if I take the 
liberty of butting my head into the conversation.

At 06:09 PM 7/7/2005 +0200, Thomas D wrote:

>I hope Windows users would not be lost by the change to Zebra.

They shouldn't be.. Zebra runs fine under Windows, and is use by one or two 
Win-based (closed-source) ILS vendors today. We'd want to make sure that 
the installation process is smooth and well-integrated with the install 
process for the rest of Koha, that's all.

>A Unix system might be installed at their site for actually running Koha.
>It could be administered remotely if on site experience was lacking.

Yes indeed. For remote support, I personally have a great preference for 
Unix, although I guess if you know what you're doing, it is possible to do 
some remote support of a Win-box, too.

>It would, however, be nice if the Event module and other software could be
>installed on a wider range of systems.  Apparently OSX is also problematic
>for the event module.

I am guessing that this comment might address the Net::Z3950 module. For 
various reasons, I would really like to see Koha use instead a newer Z39.50 
client API, preferably one based directly on the YAZ/ZOOM high-level client 
API in C. The YAZ/ZOOM API was developed after Net::Z3950, and it really 
represents a generational leap... here are some of the benefits:

o YAZ/ZOOM can normalize MARC records into UTF-8 and XML, which potentially 
simplifies a lot of things on the client side.

o Unlike the Event module in Net::Z3950, which has caused some problems 
over the years, the multiplexing code in YAZ/ZOOM is very robust, and very 
efficient.

o YAZ/ZOOM supports certain extensions to Z39.50 which allows a Perl 
application to directly manage databases in a Zebra installation, update 
records, etc. I believe that this may be the neatest and most efficient way 
to integrate an application like Koha with Zebra.. superior to system() 
calling the Zebra command-line interface, and more robust than the native 
Zebra Perl API, which was developed by a third party and which may not be 
entirely reliable.

o It includes support for the Z39.50 next-generation protocols SRW and SRU, 
for whenever that becomes relevant.

o It integrates closely with Index Data's YAZ Proxy which provides caching 
and session-management functionality which can hugely boost performance 
when YAZ/ZOOM is used to access slower, remote targets (i.e. not Zebra). 
This is valuable if you'll look at extdending Koha's remote-searching 
capabilities in the future.

You'll see some discussion about YAZ/ZOOM at 
http://www.indexdata.dk/yaz/doc/zoom.tkl, and about ZOOM in general at 
http://zoom.z3950.org/. I can't promise that the Zebra-specific, 
database-management options are documented here, though.

The big catch is that there is not presently a Perl-wrapper directly over 
the YAZ/ZOOM "C" language API.. I ran into a fellow at ALA who used it 
indirectly, by accessing the Visual Basic implementation directly through 
Perl, under Windows, but of course that would leave our Unix customers 
stranded.  :-)   At Index Data, we've developed most of our web-based 
applications in PHP so we haven't been strongly motivated to work on this 
yet... However, we do have a functional implementation of a Perl API over 
YAZ/ZOOM floating around the office which might be a good starting point. 
Finally, I'll note that the ZOOM API is, by design, very, very simple, and 
friendly to the idioms of most programming languages.. it should not be a 
very demanding job either for us at Index Data or or for someone else, to 
roll out a neatly packaged implementation of ZOOM under Perl based on the 
YAZ/ZOOM implementation of Z39.50.

I hope this helps clear up some issues, and maybe spark some discussion 
about the integration issues.

--Sebastian
--
Sebastian Hammer, Index Data, www.indexdata.com
Direct phone: (603) 209-6853 Fax: (603) 357-1813