Re: [Koha-devel] z39.50 client: extended services

[MJ Ray]

Roger Horne <address@hidden> wrote:
> Several years ago MJ Ray suggested replacing the daemon with a z3950 program
> that was called when needed: has this idea been completely dropped? 

Years, really? The problem with it is that the z3950 servers would
only have a relatively short time to answer. I've not dropped the idea,
but I've no way to fund the necessary learning, experiments and
programming time right now and just keep bodging the daemon for people.

> It may be, of course, that I have set up the client incorrectly for one or
> more of the servers. Are there any detailed instructions anywhere? 

It seems rather fiddly to debug IMO. Basically, one watches the z3950*
tables and the daemon's logfile and see what it's saying as a query is
submitted.

Even so, I still had one of my client libraries banned from a z3950
server following undetected problems and repeated requests that were
more-or-less a denial of service attack.

> In particular I note that if the standard scheme is set up for the intranet
> the client will set the download to use MARC21 by default while if it is set
> up as NPL, MARC21 is not an option, and the default is USMARC. Does this
> make a difference? ie will some servers refuse to send data in particular
> versions of MARC and will Koha translate between them?

z3950daemon experts need to answer that, but I think MARC21 and USMARC are
close enough to usually both work.

> And if a server is
> listed as only sending data using GRS-1 or SUTRS etc and not MARC, does that
> mean that it cannot be used with the Koha client? [...]

I don't think we can use those ones. I don't think it would be too hard
to extend koha to support that, but I'm working on the installer next.

> And finally, does the three seconds used by the daemon/script prevent data
> from being collected from slow servers, ie is the connection dropped before
> they can reply? If so, which script is it to be found in?

z3950 is usually served over UDP, which is sort-of
connectionless. I see COPAC only offers TCP. I'm not sure how
that works with the daemon. I think I only have UDP servers
working at present.

> Would it be possible for the "found" display to show more detail, and if so
> which file needs altering? [...]

Get the URL of the "found" display (info or properties from the right-click
menu if nothing else) and that tells you the script which may need altering.
The script will probably name the tmpl file which will also need altering to
display the extra output from the script.

Hope that helps,
-- 
MJ Ray (slef), K. Lynn, England, email see http://mjr.towers.org.uk/