Research And Design Of Communication Mechanism Of Distributed Cooperative System Based On The Hybrid Structure

With the rapid development of the computer network technology and the unceasing expansion of the scale of distributed system in many fields, the future of distributed system will be based on the synergic distributed systems. The designing ideology of the synergic distributed systems is separate calculation and collaboration, and the design focus on achieving collaborative communication among high dynamic components which is the high degree of autonomy in the system. In distributed cooperative system the corresponding each component has characteristics of reducing the coupling in time, space and synchronization, while bottleneck and performance problems which is brought the central server of traditional C/S structure model building traditional distributed system seriously hinder the scalability of distributed cooperative system.P2P (Peer-to-Peer) network model and its communications technology bring new opportunities for building distributed cooperative system. The paper combining the C/S model and P2P network model put forward a kind of safe and efficient hybrid structure model, and mainly study and found communication mechanism of the cooperative system on the hybrid structure model.The communication mechanism of the cooperative system mainly depends on the choice and design of collaborative model. The paper adopts Message Oriented Middleware based on PUB/SUB collaborative model to accomplish the system communication. The PUB/SUB model used to adopt a form based on content and so on, and matching algorithm based on keyword, but now the paper applies RDF (Resource Description Framework) to the design of PUB/SUB data model-essential it describe communicating data item in the form of triple. We use RDF/XML modeling data exchange format, and use RDF graph modeling event data model, and RDF model graph modeling subscription data model. The data model based on the RDF make system unimpeded communication in any heterogeneous system. On the basis of the data model, we bring forward a kind of semantic matching algorithm. The algorithm, convert RDF/XML message into the system data structure, can efficiently complete matching between the event and subscription information and so that the ratio between the matching success rate and matching time reach the minimum. We introduce the overlay network layer of the hybrid structure, using C/S structure and the structured P2P network model based on the DHT to construct the overlay network and joining the interest nearby mechanism of the Small-World model, and organize the hybrid P2P network according to the subscription similarity. We adopt overlay layer multicast techniques and protocols to spread event and subscription. Thereby, this enhances the event routing efficiency and reduce maintenance cost of the subscription. A Lamport logical clock strategy is introduced into route algorithm to ensure ordered and reliability of the event routing. In conclusion, under the hybrid structure, the communication mechanism of cooperative system based on PUB/SUB collaborative model bring system to complete independent process communications running on any heterogeneous platforms. Consequently, the design improves the scalability of the system and makes the system higher performance.