[glue-wg] uk.ac.gridpp.vcycle added

[Andrew McNab]

> On 15 Oct 2015, at 11:46, stephen.burke at stfc.ac.uk wrote:
> 
> Meredith, David (STFC,DL,SC) said:
>> Or, for ease here are the details:
>> +"ServiceType_t","uk.ac.gridpp.vcycle","Vcycle manages the lifecycle of
>> VMs running jobs on cloud resources for LHCb, ATLAS, CMS, and GridPP
>> DIRAC VMs.","Recommended",,
>> +"ServiceType_t","uk.ac.gridpp.vac","A virtual machine factory system
>> for operating clusters at grid sites","Recommended",,
> 
> I don't think that's enough to be sure, at least for me. The basic point is that a ServiceType identifies the entirety of a service, rather than a component or aspect of one. I remember how vac started off but I don't know how it has evolved since - is it now an entire computing service as an alternative to e.g. CREAM or ARC? GLUE ServiceTypes are unique, a given service can only have one, unlike the GOC DB.

I think in GLUE2 terms, both Vac and Vcycle are ComputingServices. They have ComputingShares (types of VM that can be created, associated with experiments, with limits, numbers running etc) but they don’t expose any endpoints, as Vac or Vcycle decides what VMs to launch rather than receiving external requests, and there’s no API for asking what a VM is doing (the VM is responsible for reporting that to the experiment’s pilot framework or whatever.)

Both these systems are exactly equivalent to CREAM and ARC from the point of view of a pilot framework, except the framework doesn’t have to submit pilot jobs as that is all done by their VMs.

Cheers

 Andrew

--
Dr Andrew McNab, High Energy Physics, 
University of Manchester, UK, M13 9PL.
www.hep.manchester.ac.uk/u/mcnab
Skype: andrew.mcnab.uk