Active CoordinaTion (ACT) - toward effectively managing virtualized multicore clouds

A key benefit of utility data centers and cloud computing infrastructure is the level of consolidation they can offer to arbitrary guest applications, and the substantial saving in operational costs and resources that can be derived in the process. However, significant challenges remain before it becomes possible to effectively and at low cost manage virtualized systems, particularly in the face of increasing complexity of individual many-core platforms, and given the dynamic behaviors and resource requirements exhibited by cloud guest VMs. This paper describes the active coordination (ACT) approach, aimed to address a specific issue in the management domain, which is the fact that management actions must (1) typically touch upon multiple resources in order to be effective, and (2) must be continuously refined in order to deal with the dynamism in the platform resource loads. ACT relies on the notion of class-of-service, associated with (sets of) guest VMs, based on which it maps VMs onto platform units, the latter encapsulating sets of platform resources of different types. Using these abstractions, ACT can perform active management in multiple ways, including a VM-specific approach and a black box approach that relies on continuous monitoring of the guest VMs´ runtime behavior and on an adaptive resource allocation algorithm, termed Multiplicative Increase, Subtractive Decrease Algorithm with Wiggle Room. In addition, ACT permits explicit external events to trigger VM or application-specific resource allocations, e.g., leveraging emerging standards such as WSDM. The experimental analysis of the ACT prototype, built for Xen-based platforms, use industry-standard benchmarks, including RUBiS, Hadoop, and SPEC. They demonstrate ACT´s ability to efficiently manage the aggregate platform resources according to the guest VMs´ relative importance (class-of-service), for both the black-box and the VM-specific approach.