Evaluation on network load balancing in Xen

Network load balancing is usually used to distribute workload across multiple network links, to improve the scalability and availability of network servers. Virtual machine is a technique in consolidated servers, co-located hosting facilities, distributed web services, and security platforms. We have implemented load balancing by NICs bonding on Xen which is an open source software for virtualization. The bonding of NICs also provides fault tolerance using network redundant connection to reduce network downtime. Two approaches are presented using bonding driver in Linux operating system with Xen. The evaluation shows that, bonding physical NICs in Xen virtual machine monitor (VMM) brings a higher throughput and lower CPU cost. Bonding in DomU has certain advantages in data path redundant and short message responses at the price of costing extra 10% CPU resources.