Preemptable priority based dynamic resource allocation in cloud computing with fault tolerance

Today, cloud computing serves as a request response model, where a client makes request for various available services on “pay as you go basis”. Cloud computing offers a dynamic flexible resource allocation phenomenon. For reliable and guaranteed services there must be a scheduling mechanism that all resources are efficiently allocated to satisfy the customer's request. Cloud services are based on scalability, availability, security and fault tolerance features. Service provisioning in cloud is based on SLA. Service level agreement is the terms of cloud provider's contracts with customers to define the level(s) of service being sold in plain language terms. QoS (quality of service) plays important role in cloud environment. Resource scheduling and service deployment is done by considering multiple SLA parameters like CPU requirement, network bandwidth, memory and storage. In this paper we propose an algorithm which perform resource preemption from low priority task to high priority task and advanced reservation for resources considering multiple SLA parameters for deploying service. This algorithm is also effective for fault tolerance mechanism.