Chinese Journal of Electronics
Vol.25, No.4, July 2016
Reusing Service Process Fragments with a
Consensus Between Service Providers and Users
∗
YANG Rong
2
,LIBing
1
, WANG Jian
3
, LI Zengyang
1
and HU Yan
4
(1. International School of Software, Wuhan University, Wuhan 430072, China)
(2. College of Computer Science and Technology, Hubei University of Science and Technology, Xianning 437100, China)
(3. State Key Laboratory of Software Engineering & School of Computer, Wuhan University, Wuhan 430072, China)
(4. Science and Technology on Integrated Information System Laboratory, Institute of Software, University of Chinese
Academy of Sciences, Beijing 100190, China)
Abstract — Recent years have witnessed a rapid
growth in using Web services for data publishing and
sharing among organizations. To improve the efficiency
of software development and economize on human and
material resources, service reuse is viewed as a powerful
means which will not only reuse atomic services, but also
reuse arbitrary granularities of Service process fragments
(SPFs). However, effectively reusing arbitrary granulari-
ties of SPFs has not been solved yet, let alone taking di-
verse QoS preferences of service providers and users into
account. In this paper, we propose a novel method of SPF
reuse, named SCKY, based on the Cocke-Kasami-Younger
(CKY) algorithm. We first present an extended CKY to
do SPF-query. Then we address how to do SPF-query by a
probability CKY, i.e., return a SPF with maximum emer-
gence probability. Finally, we explore the SPF-query with
a consensus of QoS preferences between service providers
and users. Through a set of experiments, the effectiveness
and robustness of our approach are evaluated.
Key words — Cocke-Kasami-Younger algorithm, Ser-
vice reuse, Service process fragment, QoS preferences.
I. Introduction
Communicating over private or public networks to vir-
tually form a single logical system, Web services con-
sist of a distributed computing infrastructure made up
of many different interacting application modules. Since
the capability provided by a single Web service is lim-
ited, Web services usually need to be composed as work-
flows (i.e., service processes) to achieve more complex
tasks or to mash up data from different data resources
by using business process description languages, such as
BPEL
[1]
and ORC
[2]
. Meanwhile, considering the similar
functionalities of services, quality-aware services compo-
sition has received great attention nowadays
[3]
,whichis
viewed as a problem of Multiple criteria decision mak-
ing (MCDM). Particularly Automatic service composi-
tion (ASC) has been widely investigated
[4,5]
,whichcan
decrease the workload of system exploitation by deeper
level of service reuse. In addition, many algorithms have
been presented to improve the efficiency of ASC.
Reusing SPFs can not only decrease the composition
time, but also improve the reliability of the whole com-
position process. Therefore, reusing SPFs can contribute
much to service composition. In particular, when we take
the diverse QoS preferences and expectations of service
users and providers into account, whose goals are gener-
ally Web services searching or advertisement, the selection
of composite process is more difficult. We need a method,
which can balance the different preferences of service users
and providers to reach a consensus.
In the scenario of diverse QoS preferences on Web
services, many literatures focus on finding skyline
services
[6−10]
. To improve the match efficiency, most of
them present to find k typical skyline services or focusing
on k-dominance skylines selection
[7]
. Unfortunately, few
of them consider the preferences of users and providers.
More often, a weighting mechanism is leveraged in which
users express their preferences over different quality pa-
rameters as numeric weights. Then, a linear utility func-
tion is used, where the summation of all weighted QoS
value terms is taken as quality measurement for each can-
didate composite solution in the multiobjective optimiza-
tion problem
[11−14]
. As a result, the composition with the
highest utility value will be returned to the user. However,
∗
Manuscript Received Dec. 17, 2014; Accepted Apr. 30, 2015. This work is supported by 973 Program of China (No.2014CB340401)
and the National Natural Science Foundation of China (No.61273216, No.61202031, No.61272111).
c
2016 Chinese Institute of Electronics. DOI:10.1049/cje.2016.07.003