1. An Overview of OGSA-DAI Kostas Tourlas tourlas@nesc.ac.uk

2. ReSC Access Grid meeting, May 20052 Goals for OGSA-DAI l Aim to deliver application mechanisms that: u Meet the data requirements of Grid applications l Functionality, performance and reliability l Reduce development cost of data-centric Grid applications l Provide consistent interfaces to data resources u Acceptable and supportable by database providers l Trustable, imposed demand is acceptable, etc. l Provide a standard framework that satisfies standard requirements l A base for developing higher-level services u Data federation u Distributed query processing u Data mining u Data visualisation

3. ReSC Access Grid meeting, May 20053 Core features of OGSA-DAI l An extensible framework for building applications u Supports relational, xml and some files l MySQL, Oracle, DB2, SQL Server, Postgres, XIndice, CSV, EMBL u Supports various delivery options l SOAP, FTP, GridFTP, HTTP, files, email, inter-service u Supports various transforms l XSLT, ZIP, GZip u Supports message level security using X509 u Client Toolkit library for application developers u Comprehensive documentation and tutorials l Fourth production release coming up: u OGSI (GT3), WS-I (OMII) and WS-RF (GT4) flavours l Highly extensible u Strength is in customising out-of-box features

4. ReSC Access Grid meeting, May 20054 Why Use OGSA-DAI l Provides common access view u Regardless of underlying infrastructure u Exposed through Java API or XML l Integrates well with other Grid software u OGSA, WSRF and OMII compliant l Flexibility u OGSA-DAI’s major selling point! u Extensible activity framework u Won’t tie you to storage infrastructure

5. ReSC Access Grid meeting, May 20055 Why You Might Not Want To Use OGSA-DAI l OGSA-DAI slower than direct connection methods u E.g., compared to JDBC u This should improve with time l Scalability issues u Mostly but not completely known u Depend on type of use (e.g. delivery mechanism) l Only planning to use one type of data resource u and don’t care about interoperability with other Grid software u OGSA-DAI an overkill in that case

6. ReSC Access Grid meeting, May 20056 Considerations checklist l Grid-enabled solution required? l Web-service interfaces desirable? u Data access by apps as well as individuals l FTP/GridFTP delivery acceptable? u Mitigates against SOAP limitations l Workflow control required? u More than just single, isolated queries l Diverse data resources? u E.g., databases & flat files l Format translations & transforms required? u E.g., XML to SQL, or between file formats l Java development effort available? u A few weeks, with support from OGSA-DAI team

7. ReSC Access Grid meeting, May 20057 Further info l The OGSA-DAI Project Site: u http://www.ogsadai.org.uk l The DAIS-WG site: u http://forge.gridforum.org/projects/dais-wg/ l OGSA-DAI Users Mailing list u users@ogsadai.org.uk u General discussion on grid DAI matters l Formal support for OGSA-DAI releases u http://www.ogsadai.org.uk/support u support@ogsadai.org.uk l OGSA-DAI training courses