Atomicity Analysis for Service Composition

PhD Thesis Proposal Defence


Title: "Atomicity Analysis for Service Composition"

by

Mr. Chunyang YE


Abstract:

Service Oriented Architecture (SOA) is an emerging software engineering
paradigm for developing distributed applications in the Internet era. In
this paradigm, web services from different organizations could be composed
to realize business goals.  To safeguard application consistency in such
an environment, atomicity is a desirable property in a service
composition, in the sense that the service composition could either
terminate successfully or abort without any side effects. However,
conventional transactional approaches are inapplicable in such environment
due to the longrunning, distributed, autonomous and heterogeneous nature
of web services. Instead, weak consistency approaches, such as exception
handling, are often adopted to resolve application inconsistency based on
the concept of atomicity sphere.

In this proposal, we propose a process algebraic framework to study the
atomicity property in a service composition using the exception handling
approach.  We discuss the following three research issues:

1) The global analysis of atomicity sphere in a service composition. In
service composition, service providers usually provide abstract public
views of their services to service consumers. These public views expose
only partial information of their services. Therefore, it is difficult to
analyze the atomicity sphere of a service composition using existing work
because they need full comprehensive information about the provided
services. To address this issue, we propose an approach to publishing the
atomicity information of services in their public views. Service consumers
could then use these public views to check the atomicity sphere in a
service composition instead of using the services.

2) The local analysis of atomicity sphere in a service composition. In
some situations, besides the details of their services, organizations may
also be not willing to share the information about its collaborators with
other collaborators in a service composition due to privacy concerns or
business reasons. To check the atomicity sphere of a service composition
in such scenarios, the global analysis approach is incompetent. To address
this issue, we propose an alternative way to check the atomicity sphere of
a service composition using a local analysis approach.

3) The detection and resolution of atomicity violations in a service
composition. Concurrent execution of services may lead to implicit
interactions between services (i.e., resource sharing). Such implicit
interactions may also cause an atomicity violation at runtime even if a
service composition satisfies the atomicity sphere. To address this issue,
we propose an approach to identify only afflicted implicit interactions in
a service composition, and suppress their threats to atomicity with extra
behavior constraints.

We evaluate the framework of our proposal based on examples modeled after
a couple of real life applications, and the associated experimental
results.


Date:  			Thursday, 22 November 2007

Time:			10:00a.m.-12:00noon

Venue:  		Room 3301A
			lifts 17-18

Committee Members:      Dr. Shing-Chi Cheung (Supervisor)
                        Dr. Jogesh Muppala (Chairperson)
			Dr. Lei Chen
			Dr. Zonghua Gu


**** ALL are Welcome ****