1. Alpiri DataGrid Semantic Web meets Web Services

2. Problem: Information Fragmentation Information on products, places … fragmented –Products : Pricing info at amazon under Amazon ASIN, at CDNow under SIDs, auction info at Ebay under … –Places : Tourist info at lonely planet, travel at expedia, weather at …, maps at …, … –Universal problem … X2X and within X Leads to mess in the world of data exchange Web Services offer hope

3. But … just SOAP isnt enough Data under different names in different places –E.g., getPrice( ) Every etailer can provide SOAP based getPrice interface Onus of which SKU to use is on caller of interface Is keeping Web Services from becoming many to many No data routing tables –How does the m/c find out who has what data? Goal : caller shouldnt have to know –What name the data is stored under –Where the data is located

4. DataGrid : Inspired by DNS DNS –Pre-1983 : Batch distribution of hosts DBs –BSD 4.2 : transparently wove together a disperse set of host databases and presented a uniform interface –Key Elements : Naming, Routing, Caching & Security DataGrid –2001 : Batch dist. Data on users, products, … –Architecture inspired by DNS to solve this problem –Provides Naming, Routing, Caching & Security

5. DataGrid Functionality DNS : GetHostByName( ) DataGrid : GetData(, ) –Multiple types of objects (not just host names) –Multiple properties (not just ip addresses) E.g., GetData(San Jose, weather) GetData(Gameboy, productDetails) Types of objects & properties is extensible Issues that DataGrid protocol solves –How do you refer to San Jose (CA, not Puerto Rico) without requiring universal names for everything –How does GetData know where to get data from?

6. DataGrid Naming Two mechanisms for referring to things –By description : A MusicAlbum whose title is Dark Side of the Moon and whose authors title is Pink Floyd … –By name : isbn, amzn asins, odp cats, … Amzn:B000002UB2, CDNOW:675674146 Descriptions require core database of a few thousand terms –MusicAlbum, title, …

7. Query Routing DNS like structure for redirection Roots –Non-exclusive naming results in non-exclusive roots –Cross between search engines & DNS root Answer aggregated from multiple sources

8. Caching More sensitive to errors than DNS Pull-push caching scheme Request : Content-Length: … Proxy: Alpiri-Proxy/0.n QueryID: d8f894g Answer : Expires : … Update: QueryID: d8f894g DG Server Data Provider Update: QueryID: d8f894g www….

9. DataGrid Application : Real-time Commerce Real-time data about specials, auctions, availability, news … on products, topics, … Potential driving force for DataGrid

10. Why does it matter? Web Services are important –Bringing the internet to programs Web Services are stalled –A year of hype, no big interesting app One-one Web Services lacks network effects Have to solve name & routing problems for many to many Web Services

11. Questions?