Accommodating Data Heterogeneity in ULS Systems

1. Accommodating Data Heterogeneityin ULS Systems Christopher Scaffidi Mary Shaw Carnegie Mellon University

2. Problem: Data heterogeneityamong software elements in ULS systems • Software elements: • Created by autonomous stakeholders • Differing data formats • May switch to new formats without prior notice • End-user programmers: • Create particularly unreliable software elements • “Mash up” (integrate) software elements problem approach  proof-of-concept

3. Example: Exchanging person names Similar issues for data from users, external datasets, or the web. John Smith today Smith, John tomorrow – unexpected format!unanticipated need for “glue code” to reformat Lincolnshire MCC tomorrow – questionable!need to validate data, maybe trigger fail-over problem approach  proof-of-concept

4. Other examples ofdata format heterogeneity • Room Numbers • NSH 3103 vs Newell Simon Hall 3103 • Stocks • GOOG vs Google vs Google Corporation • Address Lines • 101 Main St.vs 101 MAIN STREETvs 101 Main Str. • Phone Numbers • 888-800-2030 vs +1 888 800 2030 vs (888) 800-2030 • State Names • California vs CA vs Calif. problem approach  proof-of-concept

5. Insight: Exchange kinds of data(rather than particular formats) John Smith303-202-3030 101 Main St. Pittsburgh, PA RAY TILL(404) 555-1203 2 PITT ST PGH, Penna. Doe, Jane+1 717 292 3030 88 Brooke Lane PITTSBURGH Pennsylvania MR. ART COR282.303.4040 15 RED RUN RD. pittsburgh PA MR. ART COR282.303.4040 15 RED RUN RD. pittsburgh PA MR. ART COR282.303.4040 15 RED RUN RD. pittsburgh PA MR. ART COR282.303.4040 15 RED RUN RD. pittsburgh PA MR. ART COR282.303.4040 15 RED RUN RD. pittsburgh PA MR. ART COR282.303.4040 15 RED RUN RD. pittsburgh PA MR. ART COR282.303.4040 15 RED RUN RD. pittsburgh PA MR. ART COR282.303.4040 15 RED RUN RD. pittsburgh PA MR. ART COR282.303.4040 15 RED RUN RD. pittsburgh PA MR. ART COR282.303.4040 15 RED RUN RD. pittsburgh PA MR. ART COR282.303.4040 15 RED RUN RD. pittsburgh PA MR. ART COR282.303.4040 15 RED RUN RD. pittsburgh PA MR. ART COR282.303.4040 15 RED RUN RD. pittsburgh PA MR. ART COR282.303.4040 15 RED RUN RD. pittsburgh PA MR. ART COR282.303.4040 15 RED RUN RD. pittsburgh PA MR. ART COR282.303.4040 15 RED RUN RD. pittsburgh PA MR. ART COR282.303.4040 15 RED RUN RD. pittsburgh PA MR. ART COR282.303.4040 15 RED RUN RD. pittsburgh PA MR. ART COR282.303.4040 15 RED RUN RD. pittsburgh PA MR. ART COR282.303.4040 15 RED RUN RD. pittsburgh PA MR. ART COR282.303.4040 15 RED RUN RD. pittsburgh PA MR. ART COR282.303.4040 15 RED RUN RD. pittsburgh PA MR. ART COR282.303.4040 15 RED RUN RD. pittsburgh PA MR. ART COR282.303.4040 15 RED RUN RD. pittsburgh PA MR. ART COR282.303.4040 15 RED RUN RD. pittsburgh PA MR. ART COR282.303.4040 15 RED RUN RD. pittsburgh PA MR. ART COR282.303.4040 15 RED RUN RD. pittsburgh PA MR. ART COR282.303.4040 15 RED RUN RD. pittsburgh PA MR. ART COR282.303.4040 15 RED RUN RD. pittsburgh PA MR. ART COR282.303.4040 15 RED RUN RD. pittsburgh PA MR. ART COR282.303.4040 15 RED RUN RD. pittsburgh PA MR. ART COR282.303.4040 15 RED RUN RD. pittsburgh PA MR. ART COR282.303.4040 15 RED RUN RD. pittsburgh PA MR. ART COR282.303.4040 15 RED RUN RD. pittsburgh PA MR. ART COR282.303.4040 15 RED RUN RD. pittsburgh PA MR. ART COR282.303.4040 15 RED RUN RD. pittsburgh PA MR. ART COR282.303.4040 15 RED RUN RD. pittsburgh PA MR. ART COR282.303.4040 15 RED RUN RD. pittsburgh PA MR. ART COR282.303.4040 15 RED RUN RD. pittsburgh PA MR. ART COR282.303.4040 15 RED RUN RD. pittsburgh PA MR. ART COR282.303.4040 15 RED RUN RD. pittsburgh PA MR. ART COR282.303.4040 15 RED RUN RD. pittsburgh PA MR. ART COR282.303.4040 15 RED RUN RD. pittsburgh PA MR. ART COR282.303.4040 15 RED RUN RD. pittsburgh PA MR. ART COR282.303.4040 15 RED RUN RD. pittsburgh PA MR. ART COR282.303.4040 15 RED RUN RD. pittsburgh PA MR. ART COR282.303.4040 15 RED RUN RD. pittsburgh PA MR. ART COR282.303.4040 15 RED RUN RD. pittsburgh PA MR. ART COR282.303.4040 15 RED RUN RD. pittsburgh PA JOHN SMITH(303) 202-3030 101 MAIN ST Pittsburgh, PA problem  approach  proof-of-concept

6. Insight: Exchange kinds of data(rather than particular formats) • Needed: Metadata indicating a reusable abstraction for validating and reformatting each kind of string-like data. • “I am sending you a string that I call a ‘phone number’, and here’s the code to validate it and reformat it” problem  approach  proof-of-concept

7. Proof of concept: Exchanging XML and HTML • Data providers label XML/HTML nodes with a “tope” • “This node is what I call a ‘phone number’, and here’s where you can find code to validate and reformat it.” • Each tope’s implementation is stored at a published URL • On receiving data, a system • Downloads the tope implementation • Executes it to validate and put data into desired format problem  approach  proof-of-concept

8. Sample code XML <!-- topesheet = http://softwaresurvey.cs.cmu.edu/topes.txt --> <mydoc><whatever> <tel>233-222-3040</tel><date>11-Jan-96</date> <tel>(203)484-2030</tel><date>12/30/2007</date> </whatever></mydoc> TopeSheet xpath:/mydoc/whatever/date{tope:url(http://www.w3c.org/topes/date_EN.xml);} xpath:/mydoc/whatever/tel{tope:url(http://myserver.com/custom_tel.xml);} Client Code ItemLoader loader = ItemLoader.FromXml(xml); ItemSet items = loader.Load("xpath:/*/tel"); List<String> values = items.FormatAs("+1 404 505 6060"); // overloaded methods let you override the topes and/or validate the data problem  approach  proof-of-concept

9. Benefits of labeling strings with topes • Systems can detect invalid inputs • Software elements can use varying formats • No explicit references to format identifiers • No need for ontology consensus • Topes are reusable for data in… • XML nodes  Database tuples • HTML tags  Webform fields • Spreadsheet cells  …and more problem  approach  proof-of-concept

10. Thank You… • To Jeff Magee, Betty Cheng, Barbara Ryder, Margaret Burnett, and others at ICSE 2007 for early feedback • To NSF for funding • To ULSSIS for this opportunity to participate