English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Since the beginning of the WLCG Project the Spanish ATLAS computing centers have participated with reliable and stable resources as well as personnel for the ATLAS Collaboration. Our contribution to the ATLAS Tier2s and Tier1s computing resources (disk and CPUs) in the last 10 years has been around 4-5%. In 2016 an international advisory committee recommended to revise our contribution according to the participation in the ATLAS experiment. With this scenario, we are optimizing the federation of three sites located in Barcelona, Madrid and Valencia, considering that the ATLAS collaboration has developed workflows and tools to flexibly use all the resources available to the collaboration, where the tiered structure is somehow vanishing. In this contribution, we would like to show the evolution and technical updates in the ATLAS Spanish Federated Tier2 and Tier1. Some developments we are involved in, like the Event Index project, as well as the use of opportunistic resources will be useful to reach our goal. We discuss the foreseen/proposed scenario towards a sustainable computing environment for the Spanish ATLAS community in the HL-LHC period. 1 ATLAS Computing Challenges at HL-LHC period In the High Luminosity LHC period (HL-LHC) the ATLAS computing demands far outstrip the budget dedicated to computing by the different countries. On the other hand, physics analysis and simulation from ATLAS are already limited by the current computing resources. Therefore, new techniques have to be developed to enhance a robust network, a key* Corresponding author: santiago.gonzalez@ific.uv.es © 2018 CERN for the benefit of the ATLAS Collaboration. CC-BY-4.0 license component in the WLCG architecture, minimize storage needs and make the most of opportunistic resources (HPCs) [1]. Assuming a flat budget for the facilities, a 20%/yr capacity growth, and a constant development effort, a ~3x shortfall of CPU resources with respect to the flat budget model is estimated for the HL-LHC (Run 4), see Figure 1. In this case, the potential use of coprocessor/GPUs has not been considered. Fig. 1. Current estimate: ~3x CPU shortfall [1]. In Figure 2, we can see ~6x shortfall by today’s estimate in Storage on disk. This is the ATLAS bigger problem because “opportunistic storage” basically does not exist. ATLAS collaboration is working on format size reductions, but it is hard to achieve large gains so ATLAS needs new approaches. A way to dramatically reduce the storage footprint is to increase the use of tape but tape access is slow and its use complicates the workflow. Fig. 2. Storage scaling to HL-LHC [1]. 2 Spanish ATLAS Tier-1 & Tier-2 Federation The Spanish computing community is formed by one Tier-1 (PIC), and a federated Tier2: ES-ATLAS T2 (50% IFIC, 25% IFAE and 25% UAM). So far, the community has provided the hardware resources fulfilling the ATLAS requirements of the Resource Review Board of the LHCC committee, contributing around 4% of the total resources of all ATLAS Tier-2s and 5% of all Tier-1s. These resources are integrated in the WLCG (World Wide LHC Computing Grid) project and follow the ATLAS Computing Model. Present resources provided are shown in the Table 1: Table 1. Hardware resources provided by the Spanish community on September 2018. Site CPU (HEPSPEC06) DISK (TB) TAPES (TB) PIC-Tier1 46200 3265 9670 IFIC-Valencia 26751 2146 IFAE-Barcelona 10420 980 UAM-Madrid 10358 1220 In the recent LHC running periods around 6 PB of data have been stored in the Spanish facilities as shows the Figure 3. Fig. 3. Disk usage in the last 6 months in Spanish sites. Concerning the facilities performance in terms of availability and reliability, Table 2 shows the values for the 2017 year. As can be seen, in both cases the average over all the Spanish sites is greater than 98%. Table 2. Site Availability and Reliability performance, based on WLCG information in the year 2017.

Spanish ATLAS Tier-1 & Tier-2 perspective on computing over the next years