Algorithms to improve scheduling techniques in IaaS cloud

Optimal resource scheduling has been a great challenge in IaaS cloud computing environment. Haizea is a VM resource management component that takes lease requests and makes scheduling decisions based on user requests. There are four types of leases in Haizea. They are immediate, BestEffort(BE), Advance Reservation(AR) and DeadLine Sensitive(DLS) leases. Immediate lease requires immediate attention. BE lease can be allocated when resources are available. AR lease requires the exact requested slot. DLS leases are BE leases with deadline. In BE leases, the starvation of resources may occur if the lease gets suspended for more number of times since it is considered as least priority and also preemptible. Immediate and AR leases will get rejected if the leases are not schedulable at that particular requested time. This will considerably increase the lease request rejection rate. For immediate, AR and DLS leases, the next free available slots are intimated to the user. Based upon the user's wish, the leases will be scheduled. This will increase the resource request acceptance rate and the system utilization rate will also increase. The cancellation of leases after submission also can be implemented.