Opportunistic High Energy Physics Computing in User Space with Parrot

The computing needs of high energy physics experiments like the Compact Muon Solenoid experiment at the Large Hadron Collider currently exceed the available dedicated computational resources, hence motivating a push to leverage opportunistic resources. However, access to opportunistic resources faces many obstacles, not the least of which is making available the complex software stack typically associated with such computations. This paper describes a framework constructed using existing software packages to distribute the needed software to opportunistic resources without the need for the job to have root-level privileges. Preliminary tests with this framework have demonstrated the feasibility of the approach and identified bottlenecks as well as reliability issues which must be resolved in order to make this approach viable for broad use.