The Worldwide LHC Computing Grid (WLCG) infrastructure
allows the use of resources from more than 150 sites.
Until recently the setup of the resources and the middleware at a site
were typically dictated by the partner grid project (EGI, OSG, NorduGrid)
to which the site is affiliated.
Since a few years, however, changes in hardware, software, funding and
experiment computing requirements have increasingly affected
the way resources are shared and supported. At the WLCG level this implies
a need for more flexible and lightweight methods of resource provisioning.
In the WLCG cost optimisation survey presented at CHEP 2015 the concept of
lightweight sites was introduced, viz. sites essentially providing only
computing resources and aggregating around core sites that provide also storage.
The efficient use of lightweight sites requires a fundamental reorganisation
not only in the way jobs run, but also in the topology of the infrastructure
and the consolidation or elimination of some established site services.
This contribution gives an overview of the solutions being investigated
through "demonstrators" of a variety of lightweight site setups,
either already in use or planned to be tested in experiment frameworks.
|Primary Keyword (Mandatory)||Computing facilities|
|Secondary Keyword (Optional)||Computing middleware|