Study Of Load Balancing Algorithm Based On Process Migration Mechanism In Heterogeneous Cluster Environment

The key problem of the computing cluster system is how to utilize all the resourceseffectively. Load balancing is a primary means to make use of all the resouxces in a clustereffectively. Process migration mechanism brings the decision made by load balancingalgorithm into effect.To share and utilize the resources effectively in the cluster environment of heterogeneousresources, we propose a Frame of Resource Sharing and Load Balancing in Cluster ofHeterogeneous Resources (HRSLBF). The HRSLBF consists of load balancing algorithm andpreemptive process migration mechanism. One of the importaflt features of HRSLBF is that itcan use all the resources in cluster in perfect harmony. In HRSLBF, all scheduling isperfOrmed from the point of view of using all resource evenly. So HRSLBF can balance theusage of all resources essentially and improve the performance of the cluster system.In HRSLBF, we propose a load balance algorithm based on multiple resouxces (LBMR).The main ideas of LBMR rely on the following. Firstly, by selecting and defining the resourceload indexes rationally, LBMR take into consideration the effect on the resource usage ofsource node and destination node by the migrant. By means of vector operations, LBMR canuse multiply resources in harmony. Secondly, LBMR adopts the smallest k-subset randomalgorithIn, and the load index information is provided by the Information Cache. Thirdly,based on the improvement degree of the expected slowdown, LBMR make decision of Whichprocess is fit for migration. LBMR is a symmetrically-initiated algorithm. LBMR iscomposed by two sender-initiated algorithIn named location-first sender-initiated loadbalancing algorithm (LFSlLB) and selection-first sender-initiated load balancing algorithm(SFSILB), and also a receiver-initiated load balancing algorithxn (mLB).Process migration mechanism brings the decision made by load balancing algoritlun intoeffect. Because all computing in cluster need communications and synchronizations atdifferent levers, process migration mechanism should support the migration of networkconnection, by which the connection before the migration of the process can be hold and thetransparency of network connection can be implemented. The transparency of networkffi Ill NreMf4%R$x#IsR%lR#{tritxconnection often results in the dependency of the souxce node and the dependency of IPCcommunication has the great opposite effect on the performance of migrant. TO solve thisproblem, we Stlldy and imPlemeni a kind of TCP connection migration technique based on thesocket migration, by which we archive the transparency and resolve the sourcecommunication dependency of TCP cormection in process migration partially.TO describe the features of inaccuracy and partiality of load infOrmation in cluster system,we propose a model of Information Weak Consistency. The problem of infOrmation weakconsistency must be considered by the load balancing algorithm Whn it perfOrms schedu1ing.In order to using the weak consistency infOrmation effectively, we propose a smallest k-subsetrandom algoritlun (SKR and conduct a lot of simulation. Oux simulations show that the SKRalgorithIn can improve the validity of the load balancing algorithIn. -Based on the SKR algorithm, we design an information Cache which contains two Cachestructuxes. The special replacemetlt algorithIn of this information Cache assures that the nodesin the Cache are the k most overloaded nodes and the k most underloaded nodes in the clustersystem. By this means, whatever the node's load state is, the load balancing algorithm can usethe information of one interested Cache to make decision effectively. This bi-Cachemechanism is very useful fOr symmetrically-initiated load balancing algorithm.The scheduling algorithm is aPplication-dependent. The characteristics of workload,especially the lifetime distribution of process have great influence on the design of loadbalancing algorithIn.