Speaker
E. Ronchieri
(INFN CNAF)
Description
The problem of finding the best match between jobs and computing
resources is critical for an efficient work load distribution in
Grids. Very often jobs are preferably run on the Computing Elements
(CEs) that can retrieve a copy of the input files from a local
Storage Element (SE). This requires that multiple file copies are
generated and managed by a data replication system.
We propose the use of scheduled on-demand Layer 2 Virtual Private
Networks (L2 VPNs) for an alternative data access model based on the
possibility to connect to the same virtual LAN both CEs and SEs from
remote Grid domains. The L2 VPN members are "close" to each other. In
this way a CE can be selected by a Resource Broker without requiring
the presence of a local file replica. This simplifies the data
management and allows a more efficient use of the network resources
on the links connecting the Grid to its main data sources.
In this paper we detail how L2 VPNs are dynamically provisioned
through the Grid Network Agreement Service. We propose a hierarchical
network resource abstraction,the Path, and we show how it can be
integrated in the Grid Information Service to perform network
resource discovery and matchmaking. We then describe the User
Interface through which the Path negotiation terms are specified by
the user and we propose a path management approach that integrates
different network technologies, namely MPLS and the Differentiated
Services architecture. The implementation details of a system
prototype are described together with some initial experimental
results.
