Transparent execution of ARC jobs on Desktop Grid resources

In the EDGI EU FP7 project a federation of Desktop Grid sites are built and maintained by the infrastructure team. These sites provide volunteer and institutional type resources in the range of hundreds of thousands of CPUs. The EDGI project offers these resources for the various gLite, ARC and UNICORE user communities and supports job execution with transparent bridging in the cases of gLite, ARC and UNICORE middleware. The paper focuses on the ARC side. A special bridging mechanism has been implemented in order to forward ARC jobs towards the Desktop Grid servers. The ARC bridge works in such a way that the A-REX execution service sees the Desktop Grid as a virtual batch system and users are able to submit to the Desktop resources seamlessly. The solution is scalable and includes handling large amount of files through a P2P distributed file system, called Attic. The paper gives a short overview of the EDGI infrastructure and introduces the technical details of the bridging mechanism. The introduced solution is also part of the EMI and EGI software stack to make it easily accessible for the ARC infrastructure providers.