Hi All, we currently develop mechanisms for reserving VMs in advance. We thought it would be a welcome addition to the OCCi spec, most likely you're already working on such capabilities. We're happy to join that activity. Philipp and Ramin will attend OGF 30 and may participate in ongoing discussions. Our use cases are (1) set of VMs for a specific time slot, (2) set of VMs for a set of specific time slots, and (3) set of VMs, each VM for a specific duration to be finished before some deadline (global to the set). Related use cases in OCCi [1]: - 2.1 SLA@SOI -- particularly, "scheduling information" - 2.3 Interop w ONE -- particularly, "Quality of Service" - 2.7 Automated Business Continuity ... -- particularly, "Quality of Service" - 2.12 Multiple Allocation -- particularly, "Definition of groups" A possible approach for ARC support would be to associate an attribute 'timespec' with each resource entity (VM) and/or set of resource entities (VMs, didn't check if the current OCCi spec provides that possibility). The timespec's format could be based on the ISO 8601 definition [2]. It would be sufficient for our use cases (except for irregular sets of time slots). Another option could be the webcal specification [3]. Similarly, reservation identifiers could be passed through (e.g., for starting VMs). There may be different options for how actually extending the spec. A subsequent issue is the relationship of reservations and allocations of VMs, e.g. 1:1, 1:N, N:1, N:M. Another aspect would be lifecycle management, particularly how do you manage failures (before and during runtime of a reservation). Think of support for notification and recovery. When we consider reserving VMs from multiple providers, transactional aspects may be of interest as well, e.g., as previously done for Grid computing [4]. But that may be a bit far into the future? What do you think about it ? Anybody else working on reservation of Cloud resources ? Best regards, Thomas [1] Open Cloud Computing Interface - Use cases and requirements for a Cloud API, http://forge.ogf.org/sf/go/doc15732 [2] ISO 8601 @ Wikipedia, http://en.wikipedia.org/wiki/ISO_8601 [3] webcal @ Wikipedia, http://en.wikipedia.org/wiki/Webcal [4] HARC, https://www.cct.lsu.edu/harc.php -- Thomas Röblitz / TU Dortmund / ITMC & LS Service Computing / Computer Science Department / +49-231-7555329