Research On Routing Mechanisms Of Publish/Subscribe Systems In Peer-to-Peer Networks

In the large-scale distributed networks, Publish/Subscribe system is one of the mostimportant information communication models. As information sharing and newsdissemination flourish, Publish/Subscribe system has become the hotspot of research inthe distributed networks. Peer-to-peer network, which is an important kind of distributednetwork, supports information interaction among participants with decentralized control.The main characteristics of Peer-to-peer networks include self-organization, decentralizedcontrol, decoupling, and so on. These characteristics naturally meet the requirements ofPublish/Subscribe system on time decoupling, space decoupling and synchronizationdecoupling. Compared with the traditional Publish/Subscribe system, thePublish/Subscribe system over Peer-to-Peer network has much more scalability, flexibilityand self-adaptability, and it has become the first choice in the large-scale Peer-to-Peernetwork.Publish/Subscribe system over Peer-to-peer network needs provide efficientsubscription management, routing method, efficient event matching policy, and a reliableevent delivery algorithm with low delivery latency and low bandwidth cost. This papermainly focuses on the subscription management, routing method, event matching anddelivery algorithm of Publish/Subscribe system based on the structured Peer-to-Peernetwork.Firstly, this paper proposes a novel dynamic routing policy of the topic-basedPublish/Subscribe system based on rendezvous node, namely EScribe. EScribe, which isevolved from Scribe, is an enhanced multicast-tree Publish/Subscribe system. Each nodemaintains the subscription records of its Pastry leaf nodes by maintaining Bloom Filter.Under dynamic routing policy, a node selects a Pastry leaf node that subscribes the topicas the next hop according to the subscription records of its Pastry leaf nodes. This methodreduces the scale of multicast tree, the number of helper nodes and the redundant eventdelivery. Additionally, the maintenance time interval of multicast-tree increases with thelevel of the node in the multicast tree, and the overall maintenance cost of multicast tree isreduced at last. Secondly, we propose a novel content-based Publish/Subscribe system based onrendezvous node, namely Marshmallow, to provide efficient, scalable and adaptable eventdissemination service. Marshmallow provides an efficient event delivery algorithm withhigh reliability, low latency, low bandwidth cost based on the embedded trees of Pastryoverlay network. Meanwhile, Rendezvous node cluster is proposed to guarantee therendezvous node working without interruption. Additionally, we provide the interfaces toretrieve history events.At last, we propose a content-based Publish/Subscribe system based on spanning treerouting, namely CSTPS. CSTPS provides a content dissemination service paradigm basedon the spanning-tree routing on top of Chord overlay network. CSTPS introduces thesubscription aggregation to reduce the bandwidth cost during the subscription collection,and adopts probability forwarding policy to reduce redundant event delivery. Additionally,CSTPS avoids the node load misbalance problem.