Using Deductive Synthesis to
Assemble Grid Applications
Project Student: Bin Yang
Supervisor: Alan Bundy, Ewen Maclean
21/04/04
Motivations
• Two of the fundamental computing
research problems that require solution for
the broadest vision of eScience
– rapidly assembling
– automatic computing
--- UK e-Science Research Agenda
• Deductive Synthesis is applicable given a
suitable formalisation
21/04/2004
e-Science Open-Call Project Meeting
Workflow in the Grid
• Workflows as new Grid Services that are
created by connecting existing Grid Services
– Matlab scripts (Geodise), XML scripts (myGrid),
direct acyclic graph (Condor)
• Workflows as specifications of composite
Grid Applications
21/04/2004
e-Science Open-Call Project Meeting
A myGrid Workflow
21/04/2004
e-Science Open-Call Project Meeting
Automate W/F Generation
• Users should be saved from all the match-
checkings between Grid Services
• Workflows should be generated (semi-)
automatically
• Future users need more flexibility in
creating their Grid tasks
21/04/2004
e-Science Open-Call Project Meeting
Abstract Workflow
– Concrete Workflow
• Specific resources
• Executable
in the middleware
– Abstract Workflow
• Logical names, or
• Service classes
21/04/2004
e-Science Open-Call Project Meeting
Deductive Synthesis Approach
•
Suppose a specification of
the target program as below
21/04/2004
e-Science Open-Call Project Meeting
Proposed Semantics for extract()
• Grid Services of the type of Extract do
–
–
–
–
Take a database query as input
Acquire data from user-specified database
Apply two different filter operations on the data
Output two files
• Therefore, we have
21/04/2004
e-Science Open-Call Project Meeting
Need for an
“Application Domain Theory”
• An Application Domain Theory, that
– Describes the procedures in the Grid, as well
as some basic properties of the middleware, in
the form of first-order axioms
– Models the fundamental functionalities a Grid
environment should have
– Provides the planner the state info of the
search space
21/04/2004
e-Science Open-Call Project Meeting
Our Approach
– Flexible: users build up app. with components
– Endorse the maximum resource re-use
– Capable to deal with recursions and iterations
21/04/2004
e-Science Open-Call Project Meeting
Open Issues
– Do users need assistance in assembling, and
in case of failure, re-assembling Grid Apps?
– Do we need iteration and recursion constructs?
• Is Deductive Synthesis over-kill for this problem?
– Is a cross-domain App Domain Theory
plausible? Ontology?
21/04/2004
e-Science Open-Call Project Meeting
Conclusions
– Grid’s getting more intelligent and easy-to-use
– A well-designed Application Domain Theory, or a
formal specification, of the Grid Environment is
crucial
– Our approach enforces resource re-use
21/04/2004
e-Science Open-Call Project Meeting