ALICE, as well as the other experiments at the CERN LHC, has been building a distributed data management infrastructure since 2002. Experience gained during years of operations with different types ...of storage managers deployed over this infrastructure has shown, that the most adequate storage solution for ALICE is the native XRootD manager developed within a CERN - SLAC collaboration. The XRootD storage clusters exhibit higher stability and availability in comparison with other storage solutions and demonstrate a number of other advantages, like support of high speed WAN data access or no need for maintaining complex databases. Two of the operational characteristics of XRootD data servers are a relatively high number of open sockets and a high Unix load. In this article, we would like to describe our experience with the tuning/optimization of machines hosting the XRootD servers, which are part of the ALICE storage cluster at the Tier-2 WLCG site in Prague, Czech Republic. The optimization procedure, in addition to boosting the read/write performance of the servers, also resulted in a reduction of the Unix load.
The MONARC (MOdels of Networked Analysis at Regional Centers) framework has been developed and designed with the aim to provide a tool for realistic simulations of large scale distributed computing ...systems, with a special focus on the Grid systems of the experiments at the CERN LHC. In this paper, we describe a usage of the MONARC framework and tools for a simulation of the job processing performance at an ALICE Tier-2 site.
The Czech Republic (CR) has been participating in the LHC Computing Grid project (LCG) ever since 2003 and gradually, a middle-sized Tier-2 center has been built in Prague, delivering computing ...services for national HEP experiments groups including the ALICE project at the LHC. We present a brief overview of the computing activities and services being performed in the CR for the ALICE experiment.
We report on results of a measurement of {phi} meson production in central Pb-Au collisions at E{sub lab}=158A GeV. For the first time in the history of high energy heavy-ion collisions, {phi} mesons ...were reconstructed both in the K{sup +}K{sup -} and the dilepton decay channels in the same experiment. This measurement yields rapidity densities near midrapidity, from the two decay channels, of 2.05{+-}0.14(stat){+-}0.25(syst) and 2.04{+-}0.49(stat){+-}0.32(syst), respectively. The shape of the measured transverse momentum spectrum is also in close agreement in both decay channels. The data rule out a possible enhancement of the {phi} yield in the leptonic over the hadronic decay channel of a factor 1.6 or larger at the 95% C.L. This rules out the discrepancy reported in the literature between measurements of the hadronic and dimuon decay channels by two different experiments.
The results of the incidence of acute respiratory viral infection in the village of Poltava in the Krasnoarmeysky district of the Krasnodar Territory in the epidemiological season (December 2018 – ...March 2019) are presented. There were 120 people under the supervision of 18 to 79 years of age who sought medical help from a local GP in this time range with complaints of fever, weakness, headache, cough, sleep disturbance, sore throat when swallowing, chest pain cage, nasal congestion and hoarseness of voice. All applicants were diagnosed with Acute Respiratory Viral Infection. In all cases, the diagnosis was based on the collection of complaints, anamnesis, physical examination data, a clinical blood test with a white blood cell count and a general urinalysis. It was established that the body temperature of patients with adequately prescribed therapy and the implementation of all the prescribed recommendations lasted from three to five days from the start of treatment, in rare cases up to seven days. The duration of the disease and the number of days of disability during inpatient treatment most often ranged from 10 to 15, with outpatient treatment – 5–10. In rare cases, the duration of the disease and treatment was several days. In the treatment of acute respiratory viral infection, the following drugs were used: Tamiflu, Nomides, Influceil, Ingavirin, Kagocel and Ergoferon.
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