An Efficient and Transparent Approach for Adaptive Intraand InterNode Virtual Machine Communication in Virtualized Clouds Network IO workloads are dominating as one of the leading costs for most of the virtualized clouds. One way to improve the inter virtual machine (VM) inefficiency is to build shared memory channels between VMs colocated on the same physical node to bypass traditional TCPIP network stack, so that the overhead is reduced by shorter communication path and fewer kernel interactions. However, it is a key challenge for existing work to achieve high performance interVM communication while keeping the capability of VM live migration, and most of existing work are neither seamlessly agile in the presence of VM live migration nor transparent to upper users as well as to operating system kernels, which limits the application of current colocation aware sharedmemory based approaches. In this paper, we present the design and implementation of XenVMC, an adaptive and transparent interVM communication system for high performance network IO in virtualized clouds. With proposed dynamic colocated VM membership update mechanism, XenVMC is applicable not only to intranode VM communication, but also to crossnode communication. It also supports adaptive switching between sharedmemory based channel and traditional networkbased channel in case of VM live migration, with the aid of proposed VM migration perception and handling mechanisms. XenVMC enables efficient data transmission for both TCP and UDP workloads, with multilevel transparency guaranteed. Extensive experiments show that XenVMC achieves better performance for both TCP and UDP workloads with high transparency, compared with both native virtualized environment and representative existing work. Experimental results also show that it is capable of automatically handling VM migration correctly with acceptable latency.

Affinity AwareScheduling of Live Migration of Virtual Machines Under Maintenance Scenarios During maintenance and disaster recovery scenarios, Virtual Machine (VM) intersite migrations usually take place over limited bandwidthxe2x80x93typically Wide Area Network (WAN)xe2x80x93which is highly affected by the amount of interVM traffic that becomes separated during the migration process. This causes both a degradation of the Quality of Service (QoS) of intercommunicating VMs and an increase in the total migration time due to congestion of the migration link. We consider the problem of scheduling VM migration in those scenarios. In the first stage, we resort to graph partitioning theory in order to partition the VMs into groups with high intragroup communication. In the second stage, we devise an affinitybased scheduling algorithm for controlling the order of the migration groups by considering their intergroup traffic. Comprehensive reallife experimental results and simulations show that our approach in some cases is able to decrease the volume of separated traffic by a factor larger than 60%.