Integration of NEMO into an existing particle physics environment through virtualization

With the ever-growing amount of data collected with the experiments at the Large Hadron Collider (LHC) (Evans et al., 2008), the need for computing resources that can handle the analysis of this data is also rapidly increasing. This increase will even be amplified after upgrading to the High Luminosity LHC (Apollinari et al., 2017). High-Performance Computing (HPC) and other cluster computing resources provided by universities can be useful supplements to the resources dedicated to the experiment as part of the Worldwide LHC Computing Grid (WLCG) (Eck et al., 2005) for data analysis and production of simulated event samples. Computing resources in the WLCG are structured in four layers – so-called Tiers. The first layer comprises two Tier-0 computing centres located at CERN in Geneva, Switzerland and at the Wigner Research Centre for Physics in Budapest, Hungary. The second layer consists of thirteen Tier-1 centres, followed by 160 Tier-2 sites, which are typically universities and other scientific institutes. The final layer are Tier-3 sites which are directly used by local users. The University of Freiburg is operating a combined Tier-2/Tier-3, the ATLAS-BFG (Backofen et al., 2006). The shared HPC cluster »NEMO« at the University of Freiburg has been made available to local ATLAS (Aad et al., 2008) users through the provisioning of virtual machines incorporating the ATLAS software environment analogously to the bare metal system at the Tier-3. In addition to the provisioning of the virtual environment, the on-demand integration of these resources into the Tier-3 scheduler in a dynamic way is described. In order to provide the external NEMO resources to the user in a transparent way, an intermediate layer connecting the two batch systems is put into place. This resource scheduler monitors requirements on the user-facing system and requests resources on the backend-system

Dynamic Virtualized Deployment of Particle Physics Environments on a High Performance Computing Cluster

The NEMO High Performance Computing Cluster at the University of Freiburg has been made available to researchers of the ATLAS and CMS experiments. Users access the cluster from external machines connected to the World-wide LHC Computing Grid (WLCG). This paper describes how the full software environment of the WLCG is provided in a virtual machine image. The interplay between the schedulers for NEMO and for the external clusters is coordinated through the ROCED service. A cloud computing infrastructure is deployed at NEMO to orchestrate the simultaneous usage by bare metal and virtualized jobs. Through the setup, resources are provided to users in a transparent, automatized, and on-demand way. The performance of the virtualized environment has been evaluated for particle physics applications

Integration of a heterogeneous compute resource in the ATLAS workflow

With the ever-growing amount of data collected with the experiments at the Large Hadron Collider (LHC), the need for computing resources that can handle the analysis of this data is also rapidly increasing. This increase will even be amplified after upgrading to the High Luminosity LHC [1]. High-Performance Computing (HPC) and other cluster computing resources provided by universities can be useful supplements to the resources dedicated to the experiment as part of the Worldwide LHC Computing Grid (WLCG) for data analysis and production of simulated event samples. Freiburg is operating a combined Tier2/Tier3, the ATLAS-BFG [2]. The shared HPC cluster "NEMO" at the University of Freiburg has been made available to local ATLAS [3] users through the provisioning of virtual machines incorporating the ATLAS software environment analogously to the bare metal system of the local ATLAS Tier2/Tier3 centre. In addition to the provisioning of the virtual environment, the on-demand integration of these resources into the Tier3 scheduler in a dynamic way is described. In order to provide the external NEMO resources to the user in a transparent way, an intermediate layer connecting the two batch systems is put into place. This resource scheduler monitors requirements on the user-facing system and requests resources on the backend-system

Virtualization of the ATLAS software environment on a shared HPC system

High-Performance Computing (HPC) and other research cluster computing resources provided by universities can be useful supplements to the collaboration’s own WLCG computing resources for data analysis and production of simulated event samples. The shared HPC cluster "NEMO" at the University of Freiburg has been made available to local ATLAS users through the provisioning of virtual machines incorporating the ATLAS software environment analogously to a WLCG center. The talk describes the concept and implementation of virtualizing the ATLAS software environment to run both data analysis and production on the HPC host system which is connected to the existing Tier-3 infrastructure. Main challenges include the integration into the NEMO and Tier-3 schedulers in a dynamic, on-demand way, the scalability of the OpenStack infrastructure, as well as the automatic generation of a fully functional virtual machine image providing access to the local user environment, the dCache storage element and the parallel file system. The performance in the virtualized environment is evaluated for typical High-Energy Physics applications

Integration of a heterogeneous compute resource in the ATLAS workflow

With the ever-growing amount of data collected with the experiments at the Large Hadron Collider (LHC), the need for computing resources thatcan handle the analysis of this data is also rapidly increasing. This increase will even be amplified after upgrading to the High Luminosity LHC [1]. High-Performance Computing (HPC) and other cluster computing resources provided by universities can be useful supplements to the resources dedicated to the experiment as part of the Worldwide LHC Computing Grid (WLCG) for data analysis and production of simulated event samples. Freiburg is operating acombined Tier2/Tier3, the ATLAS-BFG [2]. The shared HPC cluster "NEMO" at the University of Freiburg has been made available to local ATLAS [3] users through the provisioning of virtual machines incorporating the ATLAS software environment analogously to the bare metal system of the local ATLAS Tier2/Tier3 centre. In addition to the provisioning of the virtual environment, the on-demand integration of these resources into the Tier3 scheduler in a dynamic way is described. In order to provide the external NEMO resources to the user in a transparent way, an intermediate layer connecting the two batch systems is put into place. This resource scheduler monitors requirements on the user-facing system and requests resources on the backend-system.With the ever growing amount of data collected by the experiments at the Large Hadron Collider (LHC), the need for computing resources that can handle the analysis of this data is also rapidly increasing. This increase will only be amplified after upgrading to the High Luminosity LHC [1]. High-Performance Computing (HPC) and other cluster computing resources provided by universities can be useful supplements to the ATLAS collaboration’s own WLCG resources for data analysis and production of simulated event samples. The shared HPC cluster "NEMO" at the University of Freiburg has been made available to local ATLAS users through the provisioning of virtual machines incorporating the ATLAS software environment analogously to the bare metal system of the local ATLAS Tier2/Tier3 centre. In addition to the provisioning of the virtual environment, the on-demand integration of these resources into the Tier3 scheduler in a dynamic way is described. Resources are scheduled using an intermediate layer, monitoring requirements and requesting the needed resources

Dynamic Virtualized Deployment of Particle Physics Environments on a High Performance Computing Cluster

A setup for dynamically providing resources of an external, non-dedicated cluster to researchers of the ATLAS and CMS experiments in the WLCG environment is described as it has been realized at the NEMO High Performance Computing cluster at the University of Freiburg. Techniques to provide the full WLCG software environment in a virtual machine image are described. The interplay between the schedulers for NEMO and for the external clusters is coordinated through the $\texttt{ROCED}$ service. A cloud computing infrastructure is deployed at NEMO to orchestrate the simultaneous usage by bare metal and virtualized jobs. Through the setup, resources are provided to users in a transparent, automatized, and on-demand way. The performance of the virtualized environment has been evaluated for particle physics applications