LC Server Enhancements from Index Data

LC has been working with Index Data to create a front end for
our Z39.50 server that would provide us with a way to enhance
our server's performance.  Index Data has created, and we have
installed, what is essentially a Z39.50 to Z39.50 gateway by 
using two of their popular toolkits:  YAZ and an enhanced 
version of YAZ++.  For more information about these toolkits,
see the following:

   http://www.indexdata.dk/yaz/
   http://www.indexdata.dk/yazplusplus/
    (note: LC is not running the current public version of YAZ++)

In addition to enhancing our server's performance with a load
balancing mechanism (between multiple back end ports), inactivity
timers, enhanced initialization throughput to our server, query
and record caching, a way to filter problematic Bib-1 attributes,
and configurable thresholds to better control abusive client 
behavior, the front end also provides support for the following 
new services:

     -  support for delivery of XML record syntax (MARCXML is 
            the default).
     -  Mods and Dublin Core records can be requested using
            elementSetNames parameter values of "mods" or "dc".
     -  support for SRW and SRU via a gateway to our Z39.50 
            server (back end).  (Our base URL for SRW/SRU is
            http://z3950.loc.gov:7090/voyager?)

FYI, the next YAZ++ public release will contain all of the 
functionality of the version that we are currently running and 
will be under a General Public License.

Please contact me if you have any questions.
Larry

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Larry E. Dixson                    Internet:    ldix@loc.gov
Network Development and MARC
   Standards Office, LM639
Library of Congress                Telephone: (202) 707-5807
Washington, D.C.  20540-4402       Fax:       (202) 707-0115