1. BUILDING APPLICATIONS ABLE TO COPE WITH PROBLEMATIC DATA USING A DATAWARP APPROACH Stephen Crouch Peter Henderson Robert John Walters University of Southampton, UK

2. Why? Distributed applications can’t appeal to “reality” Have to use data which is available Inconsistencies are inevitable Need a strategy to cope

3. What applications assume

4. What they actually get

5. DataWarp Form a “view” Proceed on that basis Keep your view up to date When your view changes, reconsider actions which depend on it Backtrack or compensate, if necessary (Don’t commit early)

6. DataWarp

7. Using DataWarp

8. DataWarp Actions depend on data Data generated from observations using assumptions Record: which actions depend on which data which data depends on which assumptions and observations Be ready to act when assumptions fail