Abstract
The LHCb detector is undergoing a comprehensive upgrade for data taking in the LHC’s Run 3, which is scheduled to begin in 2022. The new Run 3 detector has a different, upgraded geometry and ...uses new tools for its description, namely DD4hep 2 and ROOT 12. Besides, the visualization technologies have evolved quite a lot since Run 1, with the introduction of ubiquitous web based solutions or Augmented Reality (AR) for example. The LHCb collaboration has thus started the development of a new visualization solution, based on the Phoenix 6 framework, developed jointly by several experiments in the context of the HEP Software Foundation (HSF) 10. We present here the architecture and implementation of this new solution, as well as the different contributions made to the Phoenix ecosystem. In particular we discuss a generic tool for exporting ROOT geometries to the visualization application, which can be used to display in a browser either the whole detector or subparts of it. Extensions to the Phoenix visualization primitives regarding calorimeters and performance improvements are also presented.
Upgrades to the LHCb computing infrastructure in the first long shutdown of the LHC have allowed for high quality decay information to be calculated by the software trigger making a separate offline ...event reconstruction unnecessary. Furthermore, the storage space of the triggered candidate is an order of magnitude smaller than the entire raw event that would otherwise need to be persisted. Tesla is an application designed to process the information calculated by the trigger, with the resulting output used to directly perform physics measurements.
Treatment options for chronic SIADH include water restriction (WR) and urea. The usefulness of urine osmolality to guide the choice of the treatment option is not clearly defined. We hypothesized ...that urine osmolality can indicate whether treatment with mild water restriction alone could be successful.
Retrospective Review of clinical and biochemical (blood and urine) data of patients with chronic SIADH treated for at least one year with mild WR (1.5–2l/day) either with or without urea.
Twenty nine patients were included. Nine patients were treated by mild WR. Mean serum sodium (SNa) and mean Uosm were 129±2mEq/l and 274±78mOsm/kgH2O respectively before WR, and increased to 138.5±3mEq/l and 505±87mOsm/kgH2O (P<0.001). Eight patients were treated with mild WR and 15g urea daily, the SNa and Uosm before treatment were 127.5±3mEq/l and 340±100mOsm/kgH2O respectively and increased to 136.5±1mEq/l and 490±151mOsm/kgH2O (P<0.001). Four of the eight patients had a permanent low solute intake which contributed to hyponatremia. Twelve patients needed 30g urea daily combined with mild WR. The SNa and Uosm were respectively 126±2mEq/l and 595±176mOsm/kgH2O and increased to 136.5±2mEq/l and 698±157mOsm/kgH2O (P<0.05). Uosm increased in most of the treated patients.
About 30% of patients could be treated by moderate WR alone. All these patients presented an initial urine osmolality lower than 400mOsm/kgH2O.
•In SIADH, about 30% of the patients could be treated by mild water restriction (WR).•All these patients presented an initial urine osmolality lower than 400mOsm/kg H20.•In the remaining patients, urea combined with mild WR (<1.5–2l/day) normalized SNa.
HEP software stacks are not shallow. Indeed, HEP experiments' software is usually many applications in one (reconstruction, simulation, analysis,...) and thus require many libraries - developed ...in-house or by third parties - to be properly compiled and installed. Moreover, because of resource constraints, experiments' software is usually installed, tested, validated and deployed on a very narrow set of platforms, architectures, toolchains and operating systems. As a consequence, bootstrapping a software environment on a developer machine or deploying the software on production or user machines is usually perceived as tedious and iterative work, especially when one wants the native performances of bare metal. Docker containers provide an interesting avenue for packaging applications and development environment, relying on the Linux kernel capabilities for process isolation, adding git-like capabilities to the filesystem layer and providing (close to) native CPU, memory and I/O performances.
LHCb migration from Subversion to Git Clemencic, M; Couturier, B; Closier, J ...
Journal of physics. Conference series,
10/2017, Letnik:
898, Številka:
7
Journal Article
Recenzirano
Odprti dostop
Due to user demand and to support new development workflows based on code review and multiple development streams, LHCb decided to port the source code management from Subversion to Git, using the ...CERN GitLab hosting service. Although tools exist for this kind of migration, LHCb specificities and development models required careful planning of the migration, development of migration tools, changes to the development model, and redefinition of the release procedures. Moreover we had to support a hybrid situation with some software projects hosted in Git and others still in Subversion, or even branches of one projects hosted in different systems. We present the way we addressed the special LHCb requirements, the technical details of migrating large non standard Subversion repositories, and how we managed to smoothly migrate the software projects following the schedule of each project manager.
LHCb Dockerized Build Environment Clemencic, M; Belin, M; Closier, J ...
Journal of physics. Conference series,
10/2017, Letnik:
898, Številka:
5
Journal Article
Recenzirano
Odprti dostop
Used as lightweight virtual machines or as enhanced chroot environments, Linux containers, and in particular the Docker abstraction over them, are more and more popular in the virtualization ...communities. The LHCb Core Software team decided to investigate how to use Docker containers to provide stable and reliable build environments for the different supported platforms, including the obsolete ones which cannot be installed on modern hardware, to be used in integration builds, releases and by any developer. We present here the techniques and procedures set up to define and maintain the Docker images and how these images can be used to develop on modern Linux distributions for platforms otherwise not accessible.
After the successful run 1 of the LHC, the LHCb Core software team has taken advantage of the long shutdown to consolidate and improve its build and deployment infrastructure. Several of the related ...projects have already been presented like the build system using Jenkins, as well as the LHCb Performance and Regression testing infrastructure. Some components are completely new, like the Software Configuration Database (using the Graph DB Neo4j), or the new packaging installation using RPM packages. Furthermore all those parts are integrated to allow easier and quicker releases of the LHCb Software stack, therefore reducing the risk of operational errors. Integration and Regression tests are also now easier to implement, allowing to improve further the software checks.
A New Nightly Build System for LHCb Clemencic, M; Couturier, B
Journal of physics. Conference series,
01/2014, Letnik:
513, Številka:
5
Journal Article
Recenzirano
Odprti dostop
The nightly build system used so far by LHCb has been implemented as an extension of the system developed by CERN PH/SFT group (as presented at CHEP2010). Although this version has been working for ...many years, it has several limitations in terms of extensibility, management and ease of use, so that it was decided to develop a new version based on a continuous integration system. In this paper we describe a new implementation of the LHCb Nightly Build System based on the open source continuous integration system Jenkins and report on the experience of configuring a complex build workflow in Jenkins.
The new LHCb nightly build system described at CHEP 2013 was limited by the use of JSON files for its configuration. JSON had been chosen as a temporary solution to maintain backward compatibility ...towards the old XML format by means of a translation function. Modern languages like Python leverage on meta-programming techniques to enable the development of Domain Specific Languages (DSLs). In this contribution we will present the advantages of such techniques and how they have been used to implement a DSL that can be used to both describe the configuration of the LHCb Nightly Builds and actually operate them.
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