Research And Design Of Resource Directory System In Wide-Area Grid

With the constant increase of the network bandwidth and the rapid improvement of the capability of computer, how to make use of all the disengaged resource fully in the grid and make the amounts of information richer have become an emphasis of study for the technology of information sharing. The technologies of grid just have developed to adapt this demand. Grid is called as the third generation network. Its goal is to realize the general connectivity of all the sources in the Internet, such as computed resource, memory resource, information resource, knowledge resource and so on. The technology for managing resource is one of the pivotal technologies in the field of grid, while the directory service is the most important base technology in the system of resource managing.At first, the meaning of directory service was showed in this paper. The problems were analyzed that directory service would meet under the circumstance of broad web. The characteristic, protocol content, working means, access control and the backup function for the credibility to protect system as well as the application foreground for the protocol of the Lightweight Directory Access Protocol which were acted as the present standard for directory service were analyzed. Then, the systemic framework for the Directory Service that had hiberarchy, which was targeted to rich resource and broad range and great difference of the systemic structure, was brought forward. In order to improve the systemic extensibility, stability and high effective service, a systemic model of directory service that had hiberarchy was presented in this paper. The general directory server would be acted as the marginal directory server. It made catalogue by using LDAP protocol and made management through diaphysis directory server.In the model, the marginal directory server was only to manage the directory tree information of the subarea. A few outer information of the subarea was put into the directory buffer in order to relieve the searching pressure of service system. Thediaphysis Directory Server was in charge of the index of the marginal directory servers. The request for access resource would be reflected to the correct marginal directory server of that resource's subarea. The two different directory servers in the system divided the work and made cooperation and the directory buffer was used to relieve the pressure of outer access.And then, based on the model of directory service, the author put forward an acting model, which had tree hiberarchy structure to manage resource based on the directory service system. It included a stair surrogate, several low surrogates and a lot of grid resource that had registered in the low surrogates, and the systemic structure principle and workflow of the model was illuminated in detail. In the end, combined with the application of the system, the present several safe mechanism of the LDAP directory service was introduced, and the characteristics of the several mechanisms were analyzed. The author discussed the problems in safe and the solve method for the directory service system as well.Grid will be the study hotspot in the future. With the arrival of the grid tide and the development and popularization of the broadband network technology, the application space for the technology of directory service must be wider and wider, and inevitablely, the directory service will play its important role in the field of resource sharing in grid in the future.