Internet Environment, Resource Management Model And Algorithm Research

Theories and technologies of network management is an important research field in management science and engineering. With the development of the Internet, network resources are getting richer day by day. And the research on how to carry out network resources management effectively from the perspective of management science has an important significance in improving resource utilization ratio. Therefore, a new generation network application platform and theories as well as key technologies of network management is a significant research direction on present network management. Up to now, existing technologies focuse on providing effective ways for centralized management resources. In most circumstances, resources are stored in different places and call for methods and techniques of distributed management. For instance, every school, nowadays, occupies a variety of educational resources, including courseware, excellent teachers'teaching cases, experiment cases, first-rate classes video tapes and education management software, etc. So, it's an urgent problem to be discussed that how to share those resources efficiently by means of network management and avoid developing repeatedly and blindly. It is necessary to do some research on network architecture based on distributed resource management and develop standard platform of distributed resource storage and management. As a typical application, it can make use of the platform to realize the distributed management of educational resources in primary and secondary schools and provide a universal software support platform to our country's basic education resource management. This platform will play an important role in the exchange and cooperation between primary and secondary schools across the country, and help to reach a higher teaching level.At present, most of the institutions'resources are used to store in their own Web servers for user access. It's an effective resource management method for the centralized files, but the web server bottleneck problem, the resource replica management problem, the problems of resource discovery and the network bandwidth bring challenges to this application model, and there are still many technical problems to be solved. Grid, as a network computing platform, is becoming more and more popular, and it will come up with an effective way for network resource management. On the premise of unchanging resource storage model, it is considerable to build a distributed resource management platform to integrate these resources. Therefore, we need to study the network architecture, resource management mechanism and service theory in network environment.My thesis choose the primary and secondary schools'educational resource management as background, focuses mainly on resource sharing system topology, resource discovery mechanism, resource awareness model, resource replica management model and algorithm in order to explore an effective method of resource grid platform under the Internet environment. Followings are the main details and new ideas.1. Topologies of resource sharing systems are investigated, the RP(k)C-Grid system according to network nodes processing ability and physical network parameters is built up, efficient message routing algorithm- MR-RP(k) is designed, and system bottleneck, limited extendibility as well as topology mismatch of existing topology structures are solved. Present resource management systems mainly have forms of topology including centralized, decentralized unstructured and structured mode, which have their own weaknesses: the central server is system bottleneck of centralized structure; the decentralized structure network based on the flooding mechanism is easy to lead network congestion and has limited extensibility; while structured network mainly adopts DHT mechanism to organize system nodes and resource, which may enlarge the distance with the physical adjacent connection nodes and decline the network efficiency. At the same time for the routing policy of DHT, dynamical node departure and arrival bring instabilities to the system, which call for a further research. RP(k) structure takes full advantage of Petersen's stability and ring's simplicity, which has short network diameter, simple topology structure and efficient routing policy. Compared with the other topologies, the RP(k)C-Grid system has better stability and higher communication efficiency.2. PFS resource discovery algorithm of RP(k)C-Grid is designed in the point of problem on resource searching, and the query registration mechanism is proposed to avoid repeated flooding. Compared with other searching algorithms, PFS algorithm decreases searching delay effectively, reduces hop count of searching messages, and has an excellent searching efficiency especially when the system scale is increasing.Centralized and distributed methods are the two main ways of present resource searching. The centralized resource searching has a lower extensibility and single-point failure though it is more efficient; while the distributed resource searching method based on DHT has good scalability but bad efficiency in searching on the reason of topology mismatch. PFS searching algorithm makes full use of structure characteristic of the RP(k)C-Grid system and performance advantage of the cluster head nodes, adopt a combined mechanism of cluster head probe exploration, cluster head flooding and RP(k)C scan to decrease flooding times. The query registration mechanism makes it possible for the repeated query of same resource to be responded efficiently on the cluster head nodes and make the repeated flooding avoidable.3. A global advertising algorithm of resource directory is designed to improve the resource awareness ability of the cluster head nodes, which makes nodes get a global view of the resource directory rapidly and realize quick respond of resource searching.It's an important factor of resource discovery efficiency that how the resource requester apperceives the shared resource information. By using advertisement, the supplier can promote their products in the fastest way to the consumer, and the consumer can get product information with a lowest cost through advertisement. Inspired by this marketing mode, a resource directory advertising model is proposed and a global resource directory advertising algorithm of RP(k)C-DA is designed, which is divided into two parts including Petersen inner directory advertisement and RP(k)C directory advertisement. From experiments of different system scales and comparison with methods of other papers, the advantages of the global advertising algorithm of resource directory is verified.4. A self-adaptive gateway replica algorithm based on resource access popularity queue policy is proposed from the perspective of improving replica utilization ratio and decreasing replica maintenance cost. By creating replica in other nodes for resources having hot popularity, it can balance access load and reduce replica replacement frequency of current resource node. Resource replica is an efficient way to guarantee the availability and decrease the access delay in network environment. However, it's really a tough work to deal with the replicas placement in order to achieve its highest-performance and avoid storage waste, which asks for analysis under particular topology. In the point of topology structure of RP(k)C-Grid, a self-adaptive gateway replica mechanism is proposed which creates replica in the cluster head nodes for resources from successful cross-cluster query to improve system response speed. For frequent gateway replica may increase the storage cost and the performance loss of the cluster head nodes whereas the system uses resource access popularity queue policy to manage the replica. Experiment proves that this strategy improves the system replica management performance efficiently.5. On the application background of educational resource sharing, the educational resource grid is built supported by network resource management technologies of my thesis, which realizes resource management, replica management, and resource query under network environment.On the basis of the DC metadata standard and the CELTS-42 norm, an educational resource data model is put forward to describe file resource metadata. At present, primary and secondary schools as well as educational management departments of various provinces and cities generally have high-performance servers, and accumulate amount of teaching resources. These servers have relative rule distribution in physical location, which is fit to build the structured topology. An educational resource grid instance, RP(k)C-Grid, is constructed based on research technologies of network resource management, the key technologies are analyzed and the main system models are designed. The establishment and operation way of RP(k)C-Grid system are more suitable to the present management situation of educational resources sharing for primary and secondary schools of our country.My thesis steps further to enrich and perfect the resource management model and algorithm in network environment, and provide an effective method to the exploration of network resources sharing.