Description:A VM lifecycle manager implementing the vacuum model on a group of autonomous worker-node class machines
Abstract:Vac implements the Vacuum model at the level of the individual physical worker node class machine, which is referred to as a factory machine. Each factory acts autonomously using its target shares and configuration files policy, combined with information on current VM outcomes gathered from the other factories using the VacQuery UDP protocol.
This model removes the need for the site to maintain a number of services required at grid sites, each of which can be a single point of failure. Consequently, Vac sites need: no gatekeeper service (such as CREAM or ARC) to accept incoming pilot jobs; no batch system headnode to centrally manage the pilot jobs on each worker node; no site BDII to publish status; no ARGUS server to manage pilot job access and gridmapdir mappings; no site APEL service to buffer accounting information.
Typically, running jobs in VMs at a Vac site only relies on a basic set of services (DNS, DHCP, Kickstart, Puppet) to install and configure factories, and the Vac daemon itself on each physical factory machine.