Performance Analysis of the OGSA-DAI Software Mike Jackson Mario Antonioletti, Neil Chue Hong, Alastair Hume, Amy Krause, Tom Sugden and Martin Westhead

2 Overview l Why OGSA-DAI performance is important l Profiling method l Profiling OGSA-DAI: u GDS::Perform from the server- and client- side u Using Document Object Model objects u Globus Toolkit security overheads u XML validation and third-party class inter- dependencies

3 OGSA-DAI l Open Grid Services Architecture – Data Access and Integration l XML GDS-Perform document u Sequence of data access, update, transformation, compression and/or delivery activities l Grid Data Service u Database access end-point for clients u Represents a client’s session u Perform operation u GDS-Perform => GDS-Engine => GDS-Response l XML GDS-Response document u Results u Status

4 Why is OGSA-DAI Performance Important? l OGSA-DAI added-value over direct- connection database technologies: u Data transformation u Data compression u Data delivery l BUT for standard data access scenarios OGSA-DAI performance must be competitive u Else why bother

5 Profiling Method l OGSA-DAI Release – September 2003 l GDS and its Perform operation l Profiling: u Identify where bottlenecks might be: l Developer intuition u Home in on bottlenecks and areas for detailed investigation: l Borland Optimizeit l EJ-Enterprises JProfiler u Gather detailed information over repeated runs: l System.currentTimeMillis l Apache Log4J “ SELECT * FROM table WHERE id < N ”

6 GDS::Perform – Server-side

7 A Xerces 2.4 DOM Deficiency

8 GDS::Perform – Client-side

9 Security Overhead

10 XML Validation

11 XML Validation – Another Dependency

12 Conclusions l OGSA-DAI offers more functionality than direct connection database technologies but at the expense of performance l Performance hits can occur in unsuspected places l Third-party code should be subject to performance testing before inclusion in performance-critical software l Unanticipated dependencies and performance- related behaviours may arise l Secure client-service communications are realisable using GT3 GSI without a significant degradation in performance