Z39.50 broadcast searching and Z-server response times - Perspectives from CC-interop
Purpose - Aims to focus on research and findings relating to the Z-server response times and the performance of Z39.50 for parallel searching. Design/methodology/approach - This paper begins by briefly outlining the evolution of Z39.50 and the current trends, including the work of the JISC CC-interop project. The research crux of the paper focuses on an investigation conducted with respect to testing Z39.50 server (Z-server) response times in a broadcast (parallel) searching environment. Customised software was configured to broadcast a search to all test Z-servers once an hour, for 11 weeks. The results were logged for analysis. Findings - Most Z-servers responded rapidly. "Network congestion" and local online public catalogue usage were not found to influence Z-server performance significantly. Response time issues encountered by implementers may be the result of non-response by the Z-server and how Z-client software deals with this. The influence of "quick and dirty" Z39.50 implementations is also identified as a potential cause of slow broadcast searching. Research limitations/implications - The paper indicates various areas for further research, including setting shorter time-outs and greater end-user behavioural research to ascertain user requirements in this area. The influence more complex searches, such as Boolean, have on response times and suboptimal Z39.50 implementations are also emphasised for further study. Practical implications - This paper informs the library and information science (LIS) research community and has practical implications for those establishing Z39.50 based distributed systems, as well as those in the web services community. Originality/value - The paper challenges popular LIS opinion that Z39.50 is inherently sluggish and thus unsuitable for the demands of the modem user.
z39.50 online catalogues information retrieval