First experience in operating the population of the condition databases for the CMS experiment

Reliable population of the condition databases is critical for the correct operation of the online selection as well as of the offline reconstruction and analysis of data. We will describe here the system put in place in the CMS experiment to populate the database and make condition data promptly available both online for the high-level trigger and offline for reconstruction. The system, designed for high flexibility to cope with very different data sources, uses POOL-ORA technology in order to store data in an object format that best matches the object oriented paradigm for \texttt{C++} programming language used in the CMS offline software. In order to ensure consistency among the various subdetectors, a dedicated package, PopCon (Populator of Condition Objects), is used to store data online. The data are then automatically streamed to the offline database hence immediately accessible offline worldwide. This mechanism was intensively used during 2008 in the test-runs with cosmic rays. The experience of this first months of operation will be discussed in detail.Comment: 15 pages, submitter to JOP, CHEP0

Large Hadron Collider Project

The paper presents new simulation results for the beam-induced electron cloud in the LHC beam screen. All simulations are carried out using an improved two-dimensional module for the space charge and image charge calculations. The work gives a systematic investigation of the dependence of the heat load on several parameters and gives a brief discussion of possible cures. The work investigates only the regions with strong vertical magnetic field. Administrative Secretariat LHC Division CERN CH-1211 Geneva 23 Switzerland Geneva, 7 November 1 Introduction The synchrotron radiation in the LHC creates a continuous flow of photo-electrons. These electrons are accelerated by the electric field of the bunch and hit the vacuum chamber on the opposite side of the beam pipe where they create secondary electrons which are again accelerated by the next bunch. In the field free regions, the accelerated electrons move radially towards the beam center and the particle dynamics is a one-dimensional ..

The LHC project

At the halfway point in the construction of the LHC, the project is now moving from the design and procurement phase to the installation phase, which officially started on 1st March. An overview of the progress of the project is given and the final schedule for installation and commissioning is discussed. The talk will be given in English but questions can be taken in French

Evolution of Database Replication Technologies for WLCG

In this article we summarize several years of experience on database replication technologies used at WLCG and we provide a short review of the available Oracle technologies and their key characteristics. One of the notable changes and improvement in this area in recent past has been the introduction of Oracle GoldenGate as a replacement of Oracle Streams. We report in this article on the preparation and later upgrades for remote replication done in collaboration with ATLAS and Tier 1 database administrators, including the experience from running Oracle GoldenGate in production. Moreover, we report on another key technology in this area: Oracle Active Data Guard which has been adopted in several of the mission critical use cases for database replication between online and offline databases for the LHC experiments