Patrick Fuhrmann

Deutsches Elektronen-Synchrotron · DESY - IT Informations-Technologie

The dCache project provides open source storage software deployed internationally to satisfy ever more demanding scientific storage requirements. Its multifaceted approach provides an integrated way of supporting different use cases with the same storage, from high throughput data ingest, through wide access and easy integration with existing syste...

For over a decade, dCache.ORG has provided robust software, called dCache, that is used at more than 80 universities and research institutes around the world, allowing these sites to provide reliable storage services for the WLCG experiments and many other scientific communities. The flexible architecture of dCache allows running it in a wide varie...

The development of data management services capable to cope with very large data resources is a key challenge to allow the future einfrastructures to address the needs of the next generation extreme scale scientific experiments. To face this challenge, in November 2017 the H2020 eXtreme DataCloud - XDC project has been launched. Lasting for 27 mont...

This paper describes the achievements of the H2020 project INDIGO-DataCloud. The project has provided e-infrastructures with tools, applications and cloud framework enhancements to manage the demanding requirements of scientific communities, either locally or through enhanced interfaces. The middleware developed allows to federate hybrid resources,...

This paper describes the achievements of the H2020 project INDIGO-DATACLOUD. The project has provided e-infrastructures with tools, applications and cloud framework enhancements to manage the demanding requirements of scientific communities, either locally or through enhanced interfaces enabling those infrastructures to become part of a federation...

When preparing the Data Management Plan for larger scientific endeavors, PIs have to balance between the most appropriate qualities of storage space along the line of the planned data life-cycle, its price and the available funding. Storage properties can be the media type, implicitly determining access latency and durability of stored data, the nu...

For over a decade, dCache.org has delivered a robust software used at more than 80 Universities and research institutes around the world, allowing these sites to provide reliable storage services for the WLCG experiments as well as many other scientific communities. The flexible architecture of dCache allows running it in a wide variety of configur...

In this paper we discuss design, implementation considerations, and performance of a new Resilience Service in the dCache storage system responsible for file availability and durability functionality.

For over a decade, dCache has relied on the authentication and authorization infrastructure (AAI) offered by VOMS, Kerberos, Xrootd etc. Although the established infrastructure has worked well and provided sufficient security, the implementation of procedures and the underlying software is often seen as a burden, especially by smaller communities t...

In this paper we describe the architecture of a Platform as a Service (PaaS) oriented to computing and data analysis. In order to clarify the choices we made, we explain the features using practical examples, applied to several known usage patterns in the area of HEP computing. The proposed architecture is devised to provide researchers with a unif...

X.509, the dominant identity system from grid computing, has proved unpopular for many user communities. More popular alternatives generally assume the user is interacting via their web-browser. Such alternatives allow a user to authenticate with many services with the same credentials (user-name and password). They also allow users from different...

We introduce a service for dCache that allows automatic and transparent packing and extracting of file sets into large container files. This is motivated by the adoption of dCache by new communities that often work with rather small data files which causes large time overheads on reads and writes by the underlying tape systems. Our service can be a...

Several scientific fields, including Astrophysics, Astroparticle Physics, Cosmology, Nuclear and Particle Physics, and Research with Photons, are estimating that by the 2020 decade they will require data handling systems with data volumes approaching the Zettabyte distributed amongst as many as 1018 individually addressable data objects (Zettabyte-...

The availability of cheap, easy-to-use sync-and-share cloud services has split the scientific storage world into the traditional big data management systems and the very attractive sync-and-share services. With the former, the location of data is well understood while the latter is mostly operated in the Cloud, resulting in a rather complex legal s...

We report on the status of the data preservation project at DESY for the HERA experiments and present the latest design of the storage which is a central element for bit- preservation. The HEP experiments based at the HERA accelerator at DESY collected large and unique datasets during the period from 1992 to 2007. As part of the ongoing DPHEP data...

With over ten years in production use dCache data storage system has evolved to match ever changing lansdcape of continually evolving storage technologies with new solutions to both existing problems and new challenges. In this paper, we present three areas of innovation in dCache: providing efficient access to data with NFS v4.1 pNFS, adoption of...

Recently the importance of clustering storage nodes across site boundaries is becoming more clear, thanks also to the recent ongoing initiatives in the CMS and ATLAS experiments. These approaches are supposed to promote simplicity in accessing the data and offering new possibil- ities for resilience and data placement strategies, that may also lead...

A number of storage elements now offer standard protocol interfaces like NFS 4.1/pNFS and WebDAV, for access to their data repositories, in line with the standardization effort of the European Middleware Initiative (EMI). Also the LCG FileCatalogue (LFC) can offer such features. Here we report on work that seeks to exploit the federation potential...

For over a decade, dCache has been synonymous with large-capacity, fault-tolerant storage using commodity hardware that supports seamless data migration to and from tape. In this paper we provide some recent news of changes within dCache and the community surrounding it. We describe the flexible nature of dCache that allows both externally develope...

Scientific research communities have benefited recently from the increasing availability of computing and data infrastructures with unprecedented capabilities for large scale distributed initiatives. These infrastructures are largely defined and enabled by the middleware they deploy. One of the major issues in the current usage of research infrastr...

We present results on different approaches on mounted filesystems in use or under investigation at DESY. dCache, established since long as a storage system for physics data has implemented the NFS v4.1/pNFS protocol. New performance results will be shown with the most current version of the dCache server. In addition to the native usage of the moun...

The last two decades have seen an exceptional increase of the available networking, computing and storage resources. Scientific research communities have exploited these enhanced capabilities developing large scale collaborations, supported by distributed infrastructures. In order to enable usage of such infrastructures, several middleware solution...

NFSv4.1 (pnfs) is a new industry standard which allows for access to data distributed on different file servers. The dCache storage system has implemented this protocol. The aim of this paper is to evaluate this implementation and compare it to traditional HEP protocols like dCap. We perform synthetic and simple ROOT tests as well as real analysis...

Storage Services are crucial components of the Worldwide LHC Computing Grid Infrastructure spanning more than 200 sites and serving computing and storage resources to the High Energy Physics LHC communities. Up to tens of Petabytes of data are collected every year by the four LHC experiments at CERN. To process these large data volumes it is import...

The LCG collaboration is encompassed by a number of Tier 1 centers. The Nordic LCG Tier 1, operated by NDGF, is in contrast to many other Tier 1 centers distributed over the Nordic countries. A distributed setup was chosen for both political and technical reasons, but also provides a number of unique challenges. dCache is well known and respected a...

Storage management is one of the most important enabling technologies for large-scale scientific investigations. Having to deal with multiple heterogeneous storage and file systems is one of the major bottlenecks in managing, replicating, and accessing files in distributed environments. Storage Resource Managers (SRMs), named after their web servic...

Storage management is one of the most important enabling technologies for large-scale scientific investigations. Having to deal with multiple heterogeneous storage and file systems is one of the major bottlenecks in managing, replicating, and accessing files in distributed environments. Storage Resource Managers (SRMs), named after their web servic...

We introduce gPLAZMA (grid-aware PLuggable Authorization MAnagement) for dCache/SRM in this publication. Our work is motivated by a need for fine-grained security (Role Based Access Control or RBAC) in storage systems on global data grids, and utilizes VOMS extended X.509 certificate specification for defining extra attributes (FQANs), based on RFC...

DESY operates a complete and independent LCG-2 Grid infrastructure. It provides all services needed to run a Grid. Among the supported VOs are the global HERA VOs H1, ILC, and ZEUS, which are hosted at DESY, and the LHC VOs ATLAS and CMS. Since November 2004 the Grid infrastructure is used by the HERA VOs to produce Monte Carlo events at collaborat...

This paper presents a new approach on extending the LCG system architecture to enhance job scheduling for data intensive applications in the High Energy Physics (HEP) community. First, a brief introduction to the current LCG/gLite-based implementation is given, and its in- herent problems are discussed. Then, an extended architecture is proposed wh...

In 2007, the most challenging high energy physics experiment ever, the Large Hardon Collider(LHC), at CERN, will produce a sustained stream of data in the order of 300MB/sec, equivalent to a stack of CDs as high as the Eiffel Tower once per week. This data is, while produced, distributed and persistently stored at several dozens of sites around the...

To address mass storage needs common to both DESY and Fermilab, a rate-adapting buffer cache is under development. The aim is to maximize utilization of limited tiary storage resources by the use of prefetching (read-ahead) and caching of files based on access statistics, as well as decoupling network transfer rate from tape I/O rate. A modular arc...

A European consortium formed by science and industrial partners have started the EuroStore project to develop and market a Hierarchical Storage Management System (HSM) together with a high performance parallel file system (PFS). The EuroStore project aims to design and develop a high performance file store. It will combine the features of a Hierarc...

For the mass storage system at DESY, a disk layer is under development. Decoupling the client request queue and access to the mass storage system by means of migration, staging and prefetching it shall provide full utilization of robot and drive resources. By managing distributed disk resources in the heterogeneous computing environment of DESY, op...

Technical aspects of the three major components of the H1 detector at the electron-proton storage ring HERA are described. This paper covers the detector status up to the end of 1994 when a major upgrading of some of its elements was undertaken. A description of the other elements of the detector and some performance figures from luminosity runs at...

The next consequent step in the DESY network strategy is done. The large HERA experiments are using IP and the common DESY computer network to push their detector data from the experimental caves to the dedicated datalogging machines residing in the central DESY computer center. The consequences are obvious. No vendor specific hardware for machine...

Global properties of the hadronic final state in deep inelastic scattering events at HERA are investigated. The data are corrected for detector effects and are compared directly with QCD phenomenology. Energy flows in both the laboratory frame and the hadronic centre of mass system and energy-energy correlations in the laboratory frame are presente...

Cross sections are presented for the inclusive production of charged particles measured in electron-proton collisions at low Q2 with the H1 detector at HERA. The transverse momentum distribution extends up to 8 GeV/c. Its shape is found to be harder than that observed in collisions at comparable centre-of-mass energies , and also harder than in γp...

An analysis is presented of scaling violations of the proton structure function F2(x,Q2) measured with the H1 detector at HERA in the range of Bjorken x values between x = 3 × 10−4 and 10−2 for four-momentum transfers Q>2 larger than 8.7 GeV2. The structure function F2(x,Q2) is observed to rise linearly with ln Q2. Under the assumption that the obs...

Multi-jet production is observed in deep-inelastic electron proton scattering with the H1 detector at HERA. Jet rates for momentum transfers squared up to 500 GeV2 are determined using the JADE jet clustering algorithm. They are found to be in agreement with predictions from QCD based models.

In spring 1992, the H1 detector at the HERA electron proton collider at DESY came into operation. The high bunch crossing rate of 10 MHz and the total number of 270,000 electronic channels, are placing demanding requirements on the trigger, the data logging and event reconstruction. This note describes a software filtering, data logging and event r...

The inclusive jet cross section in photoproduction has been measured as a function of transverse energy and pseudorapidity using the H 1 detector at the HERA electron-proton collider. The results are compared with leading order QCD calculations.

The inclusive jet cross section in photoproduction has been measured as a function of transverse energy and pseudorapidity using the H1 detector at the HERA electron-proton collider. The results are compared with leading order QCD calculations.

A direct search for new particles in the H1 experiment at HERA is presented for masses ranging from 35 GeV up to ~ 250 GeV. The data sample of 24 nb-1 accumulated during the first year of operation was analysed for signatures of scalar and vector leptoquarks, leptogluons, excited electrons and excited neutrinos with flavours of the first generation...

Measurements of the scattered electron energy spectrum and the differential cross sections dσ/d log(x) and dσ/dQ2 for inclusive neutral current deep inelastic electron-proton scattering are presented. The data were obtained with the H1 detector at HERA during its first running period in which 26.7 GeV electrons collided with 820 GeV protons. The da...

We present first results on the total photoproduction cross section measurement with the H1 detector at HERA. The data were extracted from low Q2 collisions of 26.7 GeV electrons with 820 GeV protons. The γp total cross section has been measured by two independent methods in the γp center of mass energy range from 90 to 290 GeV. For an average cent...

We report on the first experimental study of the hadronic final state in deep inelastic electron-proton scattering with the H1 detector at HERA. Energy flow and transverse momentum characteristics are measured and presented both in the laboratory and in the hadronic center of mass frames. Comparison is made with QCD models distinguished by their di...

We report on the investigation of the final state in interactions of quasi-real photons with protons. The data were taken with the H1 detector at the HERA ep collider. Evidence for hard interactions is seen in both single particle spectra and jet formation. The data can best be described by inclusion of resolved photon processess as predicted by QC...

General aspects of the H1 detector at the electron-proton storage ring HERA as well as technical descriptions of the magnet, luminosity system, trigger, slow-control, data acquisition and off-line data handling are given. The three major components of the detector, the tracking, calorimeter and muon detectors, will be described in a forthcoming art...

A numerical method is developed for computing relaxation-time spectra from time-domain measurements. The method starts with an assumed spectrum. This spectrum is altered and adjusted by comparing the data calculated from the assumed spectrum with the measured data. The approach is essentially an inverse Laplace transformation for the measured data....

Arkel and Snoek (1934) reported on the dielectric behavior of concentrated solutions of dipole substances. They found that the polarization shows a marked decrease with increasing dipole concentration. In the present work, it is deduced that such a behavior can be explained by nonlinear electrostatic dipole interaction. At high concentration the co...

The EuroStore project has demonstrated the feasibility to built a highly scalable and easy to run storage system covering the core requirements of tomorrows applications in HEP. The resulting prototype will be used as a base for a newly proposed followon project. The new project will approach to a full product with new features covering largescale...

DESY is one of the world-wide leading centres for research with particle accelerators and synchrotron light. At the hadron-electron collider HERA three experiments are currently taking data and will be operated until 2007. Since end of August 2004 the DESY Production Grid is operated on basis of the recent LCG-2 release. Its Grid infrastructure is...

Conference presentation

Conference presentation

Conference presentation

Conference presentation

Conference presentation

Conference presentation

Conference presentation

Conference presentation

Conference presentation

Conference presentation

Conference presentation

Poster

Conference presentation

Conference presentation

Conference presentation

Conference presentation

Conference presentation

Conference presentation

Conference presentation

Conference presentation

Conference presentation

Conference presentation

Conference presentation

Conference presentation

Conference presentation

Conference presentation

Conference presentation

Conference presentation

Conference presentation

Conference presentation

Talk

Talk

Conference presentation

Talk