Description
CPU cycles for small experiments and projects can be scarce, thus making use of
all available resources, whether dedicated or opportunistic, is
mandatory. While enabling uniform access to the LCG computing elements (ARC,
CREAM), the DIRAC grid interware was not able to use OSG computing elements
(GlobusCE, HTCondor-CE) without dedicated support at the grid site through so
called 'SiteDirectors', which directly submits to the local batch system.
Which in turn requires additional dedicated effort for small experiments on the
grid site. Adding interfaces to the OSG CEs through the respective grid
middleware is therefore allowing accessing them within the DIRAC software
without additional site-specific infrastructure. Thus enabling greater use of
opportunistic resources for experiments and projects without dedicated
clusters or an established computing infrastructure with the DIRAC software.
To send jobs to HTCondor-CE and legacy Globus computing elements inside DIRAC the
required wrapper modules were developed. Not only is the usage these types of
computing elements now completely transparent for all DIRAC instances, which
makes DIRAC a flexible solution for OSG based virtual organisations, but also
allows LCG Grid Sites to move to the HTCondor-CE software, without shutting DIRAC
based VOs out of their site.
In this presentation we detail how we interfaced the DIRAC system to the
HTCondor-CE and Globus computing elements and explain the encountered obstacles
and solutions or workarounds developed, and how the linear collider uses
resources in the OSG.
| Primary Keyword (Mandatory) | Computing models |
|---|---|
| Secondary Keyword (Optional) | Computing middleware |
