Adjustable Credit Scheduling for High Performance Network Virtualization

• Published in: 2012 IEEE International Conference on Cluster Computing pp. 337 - 345
• Main Authors: Zhibo Chang, Jian Li, Ruhui Ma, Zhiqiang Huang, Haibing Guan
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01-09-2012
• Subjects: agile credit allocation; credit scheduler; Equations; Performance evaluation; Processor scheduling; Resource management; Scheduling; Servers; shared credit; SR-IOV
• ISBN: 9781467324229; 1467324221
• ISSN: 1552-5244; 2168-9253
• DOI: 10.1109/CLUSTER.2012.27

Virtualization technology is now widely adopted in cloud computing to support heterogeneous and dynamic workload. The scheduler in a virtual machine monitor (VMM) plays an important role in allocating resources. However, the type of applications in virtual machines (VM) is unknown to the scheduler, and I/O-intensive and CPU-intensive applications are treated the same. This makes virtual systems unable to take full advantage of high performance networks such as 10-Gigabit Ethernet. In this paper, we review the SR-IOV networking solution and show by experiment that the current credit scheduler in Xen does not utilize high performance networks efficiently. For this reason, we propose a novel scheduling model with two optimizations to eliminate the bottleneck caused by scheduler. In this model, guest domains are divided into I/O-intensive domains and CPU-intensive domains according to their monitored behaviour. I/O-intensive domains can obtain extra credits that CPU-intensive domains are willing to share. Besides, the total available credits is adjusted agilely to accelerate the I/O responsiveness. Our experimental evaluation with benchmarks shows that the new scheduling model improves bandwidth even when the system's load is very high.