Research And Design On Module Of Grid Resource Co-Reservation Based On QoS

Grid Computing, a newly arisen technique that builds on the Internet, makes use of the network to share geographically dispersed resources, such as computing resources, storage resources and network resources to form a virtual super computer to provide the powerful computing ability. QoS (Quality of Service) is an issue about the long-term reliability and usability of network, with a explicate meaning how users think of network actions in the course of holding net- connection and grouping transfers. However, QoS in grid environment includes not only traditional QoS of network, but also other types QoS, such as in CPU,disk,software, etc. It makes sure that applications will obtain the capabilities in need. That is to say, QoS of grid is a general effect that applications, user terminal, network, servers act on it.For some special computing or communicating resources reservations are taken to make sure peer-to-peer QoS. Resource reservations will supply the grid real-time applications with heterogeneous resources in need, and meet the need of peer-to-peer QoS span multi-modules. So reservation is a task with full of challenges.Globus is one of the most successful grid projects. This paper introduces the structure of Globus Toolkit, installation and programming based on Globus in detail. Globus Resource Allocation Management (GRAM) supports co-allocation of computing resources, without advance resource reservation and support with other heterogeneous resources, such as network, disk etc. This means that when request for resources beyond computing resources appearing, expectant QoS services won't be necessarily realized, especially when some resources are in high demand, so co-allocation of resources will be greatly restricted.In terms of these disadvantages of Globus, we expand GRAM module of Globus Toolkit (GT) to supply reservation base on QoS, which means use the basic module that GT has supplied, such as information service, data management, file transport and security mechanism, etc. to design a more reasonable algorithm thinking over users' multi-QoS requests, and permit consultation. In the case of mostly improving the whole benefits of grid, system will accept resource requirements as many as possible,reduce the refusing rate, avoid deadlock, and make sure a more efficient collaboration among the resource nodes of grid distributing environment. It is vital that the grid system be with a limit resource. We add benefit values into the resource co-reservation algorithm. With the QoS level analysis of grid tasks and complex relationship between the overall resource usage rate and the tasks response. In terms of the characters of real-time applications, three grid resource benefit functions are designed to quantify the benefit of the system for each corresponding resource allocate scheme. Because real-time application is close relative to the time of completed, system will obtain the best benefits if application is completed in time; on the contrary, if it is beyond some point of the time, system will get no benefits even if application is completed. So we set the value "time" as the benefit function's parameter. The three benefit functions above tell us that task has its "hard deadline" and "soft deadline". So the main role of scheduler is to indicate how important each task is in terms of its priority and benefit value, and to reduce the benefit value of all the refused tasks into a minimum degree and to allocate resources reasonable.We consult RSPB algorithm in our design of scheduling algorithm. The refuse rate of RSPB algorithm is low but it only considers one CPU resource, so this paper expands it to multi-resource. Firstly setting the each requirement arrived with a correlative priority to indicate its importance, such as inner task has higher priority than external one; We also allocate a corresponding benefit function to each requirement, and append abstract QoS restrictions to qualify the "advantages" arisen when required resource is attainable. System should provide the ability...