A Research And Implementation Of Load Balance In Hybrid Cloud Based On Open Stack

Hybrid cloud has become a hot topic and main development trend of cloud computing. Hybrid cloud is a combination of private cloud and public cloud, which provisions both security and scalability. C loud users benefit much from hybrid cloud as it allows cloud administrator greater flexibility and more deployment options with an unified management platform. However, there also exist some challenges for hybrid cloud. Hybrid cloud users are faced with hardness to choose cloud provider, price fluctuation and uncertain of break down of cloud system. How to assurance the cloud system performance and global load balance for distributed applications deployed on hybrid cloud, how to make the best use of private cloud resource to help cloud users reduce cost while gurantee the service level agreement(SLA) protocol, how to avoid cloud provider lock- in problem and so on. These problems are yet to be solved.A software load balance strategy for hybrid cloud applications with the object of cost-effectiveness for cloud users is about to solve this problem. With the fact that load balancing service provisioning in a single cloud, this strategy uses a two level load balancing model. O n the cloud- level, the cloud is taken as an unit of scheduling object. On the VM- level, it uses clo ud back-end load balancing services for job distribution among virtual machines. What's more, the load balance strategy decouples job scheduling and resource allocation. For job scheduling, a Least Connections per Cost(LCC) algorithm is put forward to distribute job requests. For resource allocation, it uses a simple greedy strategy which can scale up or down automatically according to the price and performance variation of each cloud. Considering the public cloud cost is on usage and private cloud cost is almost fixed. The strategy prefer distributing jobs to private cloud first, and out-sourcing to public cloud only when the load on private cloud exceeds the threshold.At last, a hybrid cloud load balance system is implemented on the opensource cloud platform OpenStack which provides API and SDK for developers. We also use OpenStack to deploy a simulating hybrid cloud environment to test our system performance. The results shows our strategy and system can help cloud users reduce cost significantly while guaranteeing the application performance.