1. SEEK is supported by the National Science Foundation under awards 0225676. 0225665, 0225635, and 0533368. Semantic Mediation System WAVE: A Verifier for Interactive, Data-driven Web Applications WAVE: A Verifier for Interactive, Data-driven Web Applications Semantic Mediation System WAVE: A Verifier for Interactive, Data-driven Web Applications WAVE: A Verifier for Interactive, Data-driven Web Applications 3. Verify some desirable properties via WAVE, the verifier we implemented Alin Deutsch, Liying Sui, Victor Vianu, Dayou Zhou Problem Statement Overview 2. Specify Data-driven Web applications using high-level languages. Theoretical Results[PODS’04] Classes of Web application specification languages are introduced and showed automatically verifiable Explore the trade-off between expressiveness of the specification language and the feasibility of verification WAVE—A Verifier for Data-driven Web Applications[SIGMOD’05] WAVE is a sound and complete verifier for a restricted but significant class of data-driven infinite systems Coupling of database and model-checking techniques is extremely effective Database-powered Web applications may be unusually well-suited for automated verification Accomplishments Verify some desirable design requirement via WAVE, the verifier we implemented The workflow specification describing the business logic behind data-driven Web applications are increasingly complex. Static analysis tools for boosting the confidence in their robustness and correctness is required Specification can improve programmer's productivity, moreover, it also makes automatical verification possible. Verification is feasible for a significant class of database- powered (hence infinite-state) Web applications. Verification time are surprisingly good, all within seconds Case study: Dell.com-like computer shopping website This website allows user to browse, put in cart and buy computers The specification uses:  19 page schemas  4 databases tables  10 states tables  6 input relations  5 action tables PropertyTime Home page is eventually reached.(true)20 mills Users can’t cancel an order that has already been shipped.(true) 2 s. Whenever Credit Card Page is reached, User Payment Page page will eventually be reached as well.(false) 370 mills Any shipped product is previously be paid.(true) 4 s. If the input on Error Page is never empty, then whenever Error Page is reached, Home Page will eventually be reached.(true) 1 s. Experimental Results [in SIGMOD’05] 1. Motivation Desirable Requirement Desirable Requirement Semantic properties: The user cannot cancel an order that has already been shipped Navigation properties: There is a way to reach the home page from any page Soundness properties: The next Web page is unambiguously defined at any point Desired: Verification login cancel desktop laptop RAM: CPU: RAM: CPU: SCREEN: submit Matching products Details Confirmation buy print Customer Page(CP) Laptop Search (LSP)Desktop Search (DSP) Product Index (PIP) Product Detail (PDP) Confirmation (CoP) back Message Message Page (MP) state update DB action NAME: PASSWD: An Interactive, Data-driven Web Application Time Sequence of Web pages 6 8... 1091 Databa se Action Time Line 5 82 login cancel desktop laptop RAM: CPU: RAM: CPU: SCREEN: submit Matching products Details Confirmation buy print Customer Page(CP) Laptop Search (LSP)Desktop Search (DSP) Product Index (PIP) Product Detail (PDP) Confirmation (CoP) back Message Message Page (MP) NAME: PASSWD: Web Application Code