Design And Implementation Of A Load Balancing System Based On PVM

As an important parallel computing system,the cluster is widely studied and used. Thereinto, load balancing is one of the important actors affecting the efficiency of the parallel cluster system. When carrying out parallel computing, the cluster system must resolve a question of how to arrange and schedule tasks rationally and use treatment ability of every joint fully in order to reach load balancing. With the development and application of the cluster, the technology and theory of load balancing has become the research focus.PVM is one of most popular parallel programming environments. But it lacks of load balancing capability. The organizing structure, programming models and working theory of PVM are analyzed in detail in this paper. For the question of the load balancing of LINUX cluster system on PVM, a resolvent based on a load vector is presented. And a central dynamic load balancing system is realized in this paper.The load vector of this system includes the information of some key resource, such as CPU, memory and disk et al. After the structure of LINUX operating system is analyzed thoroughly, three methods of obtaining load information in LINUX are concluded, and the most efficient one, that is operating /proc file system, is achieved. In order that the value of load vector can forecast the load of the next time for tasks assignment, this system utilizes the disposed load information to construct load vector. This system schedule tasks according to task assigning list. The entire node computers deliver their load vector to the master computer periodically. The master computer maintains a load information list of the whole system. And the master computer set different values to various load information in order to construct task assigning list. The opportunity of task scheduling is decided by a strategy that node computers require tasks. That is to say if any node computer only has one task, the master computer begins to assign the new tasks basing on the task assigning listFinally, some examples are used to test the capability of the PVM without this system and the PVM with this system. The result proves that the capability of the PVM with this system is obviously higher than the capability of the PVM without this system on the cluster system with different node resource.