BIBSYS System Architecture Jan Erik Kofoed BIBSYS Library Automation ELAG 2004 in Trondheim

Jan Erik Kofoed ELAG 2004 Trondheim 2 Architecture defined: The art and technique of designing and building, as distinguished from the skills associated with construction. Encyclopædia Britannica

Jan Erik Kofoed ELAG 2004 Trondheim 3 Why care about system architecture? Architecture describes: –requirements –plans –rules –methods Architecture assure: –a correct result –an enduring result –reasonable maintenance costs

Jan Erik Kofoed ELAG 2004 Trondheim 4 A word from the directors of BIBSYS: You shall be catedral builders, not stone cutters!

Jan Erik Kofoed ELAG 2004 Trondheim 5 Retrospective Let us look at some really old architecture: The stave church: –At a.d. nearly thousand stave churches in Norway, 29 have survived. –Built in wood –special architecture based on local skills resistant to hostile weather: wind, rain and snow

Jan Erik Kofoed ELAG 2004 Trondheim 6 Holtålen stave church Trøndelag Folk Museum, Trondheim

Jan Erik Kofoed ELAG 2004 Trondheim 7 Borgund stave church Sogn og Fjordane, Lærdal

Jan Erik Kofoed ELAG 2004 Trondheim 8 From a simple framework...

Jan Erik Kofoed ELAG 2004 Trondheim 9... to complex structure

Jan Erik Kofoed ELAG 2004 Trondheim 10 The challenge Complex and enduring buildings can be built based on: –simple principles –repeated patterns –traditions –new ideas Some of the stave churches are still regulary used after 900 years. Can we create an architecture for library systems so they last a fraction of that time?

Jan Erik Kofoed ELAG 2004 Trondheim 11 Basic principles Define a model Find components to put inside the model, e.g. –XML to ISO-2901 converter for MARC records. –MARC to Dublin Core translator. –ISBN/ISSN syntax checker. –Builder of FRBR relations from MARC records. –Access control. Use frameworks Check open sources and commercial sources, before starting own development Follow your method for development faithfully: –Analysis, design, implementation, testing, deployment Involve your customers

Jan Erik Kofoed ELAG 2004 Trondheim 12 Single tier model DBMS DATA LOGIC SCREENS BUSINESS LOGIC HELP TEXT FORTRAN COBOL Natural VT100/ Xterm/ NetTerm

Jan Erik Kofoed ELAG 2004 Trondheim 13 Server Client Server Model Business Logic Client Presentation Logic User Interface Data Logic Data base

Jan Erik Kofoed ELAG 2004 Trondheim 14 Three tier model

Jan Erik Kofoed ELAG 2004 Trondheim 15 BIBSYS three tier model from 2001

Jan Erik Kofoed ELAG 2004 Trondheim 16 Multi tiered model Data managing logic Data store (DBMS) Business logic Presentation logic User interaction Client tier Logic tiersData tiers

Jan Erik Kofoed ELAG 2004 Trondheim 17 Data store (DBMS) Tiers with components using Java Technologies Client tier Logic tiersData tiers Hierarchical database Data managing logic Business logic Presentation logic User interaction Servlets Java Server Pages MVC / Struts Pure HTML Java Applets JavaBeans Appl. via Java Web- start Enterprise Java Beans XML database RDBMS Object database Java Server Faces HTML & JavaScript JavaBeans Enterprise Java Beans

Jan Erik Kofoed ELAG 2004 Trondheim 18 J2EE – Java 2 Enterprise Edition Java technology for distributed systems –i.e. Java for program, processes and components that shall communicate over a network. Technologies with weight on: –communication –exchange of messages –handling of transactions –name services –and much more

Jan Erik Kofoed ELAG 2004 Trondheim 19 Framework Methods –Task descriptions –Algorithms Tools –Building blocks –Technologies –Software, library routines Rules –What is allowed and what is disallowed

Jan Erik Kofoed ELAG 2004 Trondheim 20 MVC Model – View - Controller Purpose: –divide presentation logic from business logic Model - business logic - data manipulation - state handling View –presentation Controller –controls flow between View and Model Jakarta Struts –Implementation of MVC in Java

Jan Erik Kofoed ELAG 2004 Trondheim 21 Access control Authentication: –secure identification of a user Username password IP and domain control PKI (Public Key Infrastructure) Certificates Smartcards Authorization: –what rights do the user have? –often based on roles Accounting –useful for payment systems and statistics Signle Sign On (SSO) –Logon once, access multiple heterogeneous systems

Jan Erik Kofoed ELAG 2004 Trondheim 22 FEIDE Federated Electronic Identity for Education Norwegian system for the Higher Education sector User information from a system of distributed user databases Authentication done by Authentication Servers The authentication can be accompanied with a controlled set of attributes BIBSYS is committed to provide FEIDE for its users

Jan Erik Kofoed ELAG 2004 Trondheim 23 Shibboleth A system for sharing access information between institutions May be used for single signon Provides open source tools Used between educational institutions Based on trust... then they said to him, “Say ‘Shibboleth.’” If he said, “Sibboleth,” and could not pronounce the word correctly, they grabbed him and executed him right there at the fords of the Jordan. On that day forty- two thousand Ephraimites fell dead. Judges 12,6.

Jan Erik Kofoed ELAG 2004 Trondheim 24 Identificators Identifcators are: –unique –permanent –unambiguous For printed documents: –ISBN, ISSN For digital documents: –SICI, BICI –DOI –URN

Jan Erik Kofoed ELAG 2004 Trondheim 25 URN – Uniform Resource Name Global scope Global uniqueness Persistence Scalability Legacy support Extensibility Independence Resolution

Jan Erik Kofoed ELAG 2004 Trondheim 26 URN for Libraries General URN syntax: –URN: : NID NBN (National Bibliographic Number NSS prefixed with ISO-3166 country code E.g. URN:NBN:no-2420 Resolver service important The National Library of Norway’s resolver: – –e.g.

Jan Erik Kofoed ELAG 2004 Trondheim 27 Data models and formats Data need to be organized (of course!) Stored in one or more databases according to a data model FRBR should be considered! Metadata for cataloguing not necessary equals metadata for exchange Many systems must be supported for exchange: –MARC –Dublin Core –Presentation formats –Reference manager formats –Abstract formats MARC Dublin Core –Physical formats ISO 2709 XML

Jan Erik Kofoed ELAG 2004 Trondheim 28 Multilingual support UNICODE character set Use a framework –e.g. Java Resource Boundles No text must be hardcoded All text in separate repositories divided from the program code

Jan Erik Kofoed ELAG 2004 Trondheim 29 Data store (DBMS) Tiers with components from different frameworks Client tier Logic tiersData tiers Hierarchical database Data managing logic Business logic Presentation logic User interaction Multilingual support Screen builder Print handling Access control Metadata converter Profile management Coordinating access to other systems XML database RDBMS Object database Mobile device support Single Sign On Applying cataloguing rules Identificator management

Jan Erik Kofoed ELAG 2004 Trondheim 30 Conclusion Use a model with several tiers Build the system from simple components Components must be simple and independent of each other Use well defined interfaces between tiers and components Use open source and commercial components when available BIBSYS have chosen Java as technology platform

Jan Erik Kofoed ELAG 2004 Trondheim 31 Thank you for your attention