RELIABLE AND TIMELY EVENT NOTIFICATION FOR PUBLISH/SUBSCRIBE SERVICES OVER THE INTERNET
The publish/subscribe paradigm is gaining attention for the development of several applications in wide area networks (WANs) due to its intrinsic time, space, and synchronization decoupling properties that meet the scalability and asynchronous requirements of those applications. However, while the communication in a WAN may be affected by the unpredictable behavior of the network, with messages that can be dropped or delayed, existing publish/subscribe solutions pay just a little attention to addressing these issues. On the contrary, applications such as business intelligence, critical infrastructures, and financial services require delivery guarantees with strict temporal deadlines. In this paper, we propose a framework that enforces both reliability and timeliness for publish/subscribe services over WAN. Specifically, we combine two different approaches: gossiping, to retrieve missing packets in case of incomplete information, and network coding, to reduce the number of retransmissions and, consequently, the latency. We provide an analytical model that describes the information recovery capabilities of our algorithm and a simulation-based study, taking into account a real workload from the Air Traffic Control domain, which evidences how the proposed solution is able to ensure reliable event notification over a WAN within a reasonable bounded time window.
We have been facing the development of an increasing number of large-scale applications such as online gaming, messaging, social networking, and business intelligence. In addition, we have see the development of federations in large-scale complex critical infrastructures (LCCIs) of independent critical systems previously designed for “closed”local area networks (LANs), such as air traffic control (ATC) systems, financial infrastructure monitoring, and maritime surveillance. These applications are typically characterized by a large number of participants scattered across the world that communicate by exchanging messages on a wide area network (WAN), such as the Internet.
DISADVANTAGES OF EXISTING SYSTEM:
vIt lacks the support of quality-of-service (QoS).
vIt does not bind at delivery time.
vThey did not provide only a best-effort service.
The aim of this paper is the design of a framework that ensures reliable and timely event notification in a WAN and can be plugged in on top of a generic publish/subscribe system. Our approach combines two different techniques, each known to be reliable and timely, respectively: 1) gossip, a distributed.retransmission protocol; and 2) network coding, a Forward
Error Correction (FEC) scheme.We consider a scenario in which a publisher publishes events (i.e., application level messages) and redundant information on UDP overlay links built over the Internet, which exhibits a nonnegligible probability to have burst losses . Then, the intended subscribers apply a gossip strategy to recover from possible lost data.We provide a theoretical model to evaluate the potential benefits of gossip to retrieve the missing information. In addition, we describe a simulation- based study conducted on a real workload taken from the previously described ATC scenario, which evidences how the use of coding to send redundant information is able to reduce the latency and the message overhead for a reliable event delivery.
ADVANTAGES OF PROPOSED SYSTEM:
vIt provides Reliability and Timeliness delivery.
Processor - Pentium –IV
Speed - 1.1 Ghz
RAM - 512 MB(min)
Hard Disk - 40 GB
Key Board - Standard Windows Keyboard
Mouse - Two or Three Button Mouse
Monitor - LCD/LED
Operating system : Windows XP.
Coding Language : .Net
Data Base : SQL Server 2005
Tool : VISUAL STUDIO 2008.
Christian Esposito, Marco Platania, and Roberto Beraldi, “Reliable and Timely Event Notification for Publish/Subscribe Services Over the Internet” IEEE/ACM TRANSACTIONS ON NETWORKING, VOL. 22, NO. 1, FEBRUARY 2014