DEISA is operating a heterogeneous HPC infrastructure currently formed by eleven European national supercomputing centres that are tightly interconnected by a dedicated high performance network. The term 'heterogeneous' refers to the variety of HPC system architectures, operating systems, batch schedulers and local file systems provided by the DEISA supercomputing centres and that is typical for an HPC ecosystem.
DEISA is structured as a layer on top of the national supercomputing services by providing generalized interfaces and services that allow to access and utilize this pool of computing resources in a consistent way and therefore more efficiently. That way, the DEISA HPC infrastructure and services combine - for users and user communities - the advantage of having access to a variety of supercomputing architectures for different demanding computing purposes with the advantage provided by consistent interfaces to these different resources and services. Accordingly, the profile of using the DEISA HPC infrastructure and services can be regarded as being similar to the usage of a monolithic supercomputing system of single HPC centre.
The following section describes the current DEISA HPC infrastructure that is based on the DEISA network, on the supercomputing resources provided by the national HPC centres and on a common multi-cluster shared file system that allows a barrier-free way to read and write user data transparently into a common file space from every HPC system in DEISA. This enables the HPC users to organize their data European-wide in the same manner as they are used to work at a single national site.
The proximate section explains the unified services that DEISA is providing for HPC users and user communities. The section highlights the added value that DEISA brings to European HPC users and user communities having demanding computational applications in the areas of science and engineering.