A Decentralized Service Discovery Approach
on Peer-to-Peer Networks
ABSTRACT:
Service-Oriented Computing (SOC) is emerging as a
paradigm for developing distributed applications. A critical issue of utilizing
SOC is to have a scalable, reliable, and robust service discovery mechanism.
However, traditional service discovery methods using centralized registries can
easily suffer from problems such as performance bottleneck and vulnerability to
failures in large scalable service networks, thus functioning abnormally. To
address these problems, this paper proposes a peer-to-peer-based decentralized
service discovery approach named Chord4S. Chord4S utilizes the data
distribution and lookup capabilities of the popular Chord to distribute and
discover services in a decentralized manner. Data availability is further
improved by distributing published descriptions of functionally equivalent
services to different successor nodes that are organized into virtual segments
in the Chord4S circle. Based on the service publication approach, Chord4S
supports QoS-aware service discovery. Chord4S also supports service discovery
with wildcard(s). In addition, the Chord routing protocol is extended to
support efficient discovery of multiple services with a single query. This enables
late negotiation of Service Level Agreements (SLAs) between service consumers
and multiple candidate service providers. The experimental evaluation shows
that Chord4S achieves higher data availability and provides efficient query
with reasonable overhead.
EXISTING SYSTEM:
Traditional service discovery approaches
of the web services technology are based on Universal Description, Discovery,
and Integration (UDDI). However, centralized service registries used by UDDI
may easily suffer from problems in an open SOC environment. To overcome the
problems The Peer-to-Peer (P2P) technology provides a universal approach to
improving reliability, scalability, and robustness of distributed systems by
removing centralized infrastructures. Based on Distributed Hashing Table (DHT),
structured P2P systems can achieve even data distribution and efficient query
routing by controlling the topology and imposing constraints on the data
distribution. In this technology also problems occur.
DISADVANTAGES
OF EXISTING SYSTEM:
Although structured P2P can potentially
improve the scalability of service discovery, directly applying DHT based P2P
approaches to decentralized service discovery may be weak in guaranteeing the
availability of published service descriptions. This is because DHT-based
systems often distribute descriptions of functionally equivalent services to
the same successor node, as they have the same or similar hashing values. If
such a node fails, a service consumer will not be able to discover any of these
services. This disadvantage may result in serious problems in open and dynamic
SOC environments where unexpected failure of nodes cannot be avoided.
PROPOSED SYSTEM:
This paper proposes Chord4S, a
Chord-based decentralized service discovery approach that supports service
description distribution and discovery in a P2P manner. Chord is selected
because it is well recognized for its flexibility and scalability and is
considered suitable in large scale SOC environments.
ADVANTAGES
OF PROPOSED SYSTEM:
Chord4S takes advantages of the basic
principles of Chord for nodes organization, data distribution and query
routing.
·
The main aim of designing Chord4S is to
largely improve the availability of service descriptions in volatile
environments by distributing descriptions of functionally equivalent services
to different successor nodes.
·
In case one node fails, a service
consumer is still able to find functionally equivalent services that are stored
at other successor nodes. Another two features of Chord4S are to support
service discovery with wildcard(s) and QoS awareness.
·
Chord4S extends Chord’s original routing
protocol to support discovery of multiple functionally equivalent services at
nodes with one query, which is necessary for different successor negotiation of
a Service Level Agreement and selection of optimal service providers
ALGORITHMS USED:
ü Algorithm1:
Pseudo code for finding successor operation.
ü Algorithm2:
Function of match making.
SYSTEM CONFIGURATION:-
HARDWARE CONFIGURATION:-
ü Processor - Pentium –IV
ü Speed - 1.1
Ghz
ü RAM - 256
MB(min)
ü Hard Disk -
20 GB
ü Key Board -
Standard Windows Keyboard
ü Mouse - Two
or Three Button Mouse
ü Monitor - SVGA
SOFTWARE CONFIGURATION:-
ü Operating System : Windows XP
ü Programming Language :
JAVA/J2EE
ü Database :
MySQL
ü Java Version :
JDK 1.6 & above.
REFERENCE:
Qiang He, Member, IEEE, Jun Yan, Yun
Yang, Ryszard Kowalczyk, and Hai Jin, Senior Member, IEEE-“ A Decentralized
Service Discovery Approach on Peer-to-Peer Networks”, IEEE
TRANSACTIONS ON SERVICES COMPUTING, VOL. 6, NO. 1, JANUARY-MARCH 2013.
