63,974 research outputs found
Towards maintainer script modernization in FOSS distributions
Free and Open Source Software (FOSS) distributions are complex software
systems, made of thousands packages that evolve rapidly, independently, and
without centralized coordination. During packages upgrades, corner case
failures can be encountered and are hard to deal with, especially when they are
due to misbehaving maintainer scripts: executable code snippets used to
finalize package configuration. In this paper we report a software
modernization experience, the process of representing existing legacy systems
in terms of models, applied to FOSS distributions. We present a process to
define meta-models that enable dealing with upgrade failures and help rolling
back from them, taking into account maintainer scripts. The process has been
applied to widely used FOSS distributions and we report about such experiences
Installing, Running and Maintaining Large Linux Clusters at CERN
Having built up Linux clusters to more than 1000 nodes over the past five
years, we already have practical experience confronting some of the LHC scale
computing challenges: scalability, automation, hardware diversity, security,
and rolling OS upgrades. This paper describes the tools and processes we have
implemented, working in close collaboration with the EDG project [1],
especially with the WP4 subtask, to improve the manageability of our clusters,
in particular in the areas of system installation, configuration, and
monitoring. In addition to the purely technical issues, providing shared
interactive and batch services which can adapt to meet the diverse and changing
requirements of our users is a significant challenge. We describe the
developments and tuning that we have introduced on our LSF based systems to
maximise both responsiveness to users and overall system utilisation. Finally,
this paper will describe the problems we are facing in enlarging our
heterogeneous Linux clusters, the progress we have made in dealing with the
current issues and the steps we are taking to gridify the clustersComment: 5 pages, Proceedings for the CHEP 2003 conference, La Jolla,
California, March 24 - 28, 200
Models in the Cloud: Exploring Next Generation Environmental Software Systems
There is growing interest in the application of the latest trends in computing and data science methods to improve environmental science. However we found the penetration of best practice from computing domains such as software engineering and cloud computing into supporting every day environmental science to be poor. We take from this work a real need to re-evaluate the complexity of software tools and bring these to the right level of abstraction for environmental scientists to be able to leverage the latest developments in computing. In the Models in the Cloud project, we look at the role of model driven engineering, software frameworks and cloud computing in achieving this abstraction. As a case study we deployed a complex weather model to the cloud and developed a collaborative notebook interface for orchestrating the deployment and analysis of results. We navigate relatively poor support for complex high performance computing in the cloud to develop abstractions from complexity in cloud deployment and model configuration. We found great potential in cloud computing to transform science by enabling models to leverage elastic, flexible computing infrastructure and support new ways to deliver collaborative and open science
Automation of the Continuous Integration (CI) - Continuous Delivery/Deployment (CD) Software Development
Continuous Integration (CI) is a practice in software development where developers periodically merge code changes in a central shared repository, after which automatic versions and tests are executed. CI entails an automation component (the target of this project) and a cultural one, as developers have to learn to integrate code periodically. The main goal of CI is to reduce the time to feedback over the software integration process, allowing to locate and fix bugs more easily and quickly, thus enhancing it quality while reducing the time to validate and publish new soIn traditional software development, where teams of developers worked on the same project in isolation, often led to problems integrating the resulting code. Due to this isolation, the project was not deliverable until the integration of all its parts, which was tedious and generated errors. The Continuous Integration (CI ) emerged as a practice to solve the problems of traditional methodology, with the aim of improving the quality of the code. This thesis sets out what is it and how Continuous Integration is achieved, the principles that makes it as effective as possible and the processes that follow as a consequence, to thus introduce the context of its objective: the creation of a system that automates the start-up and set-up of an environment to be able to apply the methodology of continuous integration
Automatic instantiation of abstract tests on specific configurations for large critical control systems
Computer-based control systems have grown in size, complexity, distribution
and criticality. In this paper a methodology is presented to perform an
abstract testing of such large control systems in an efficient way: an abstract
test is specified directly from system functional requirements and has to be
instantiated in more test runs to cover a specific configuration, comprising
any number of control entities (sensors, actuators and logic processes). Such a
process is usually performed by hand for each installation of the control
system, requiring a considerable time effort and being an error prone
verification activity. To automate a safe passage from abstract tests, related
to the so called generic software application, to any specific installation, an
algorithm is provided, starting from a reference architecture and a state-based
behavioural model of the control software. The presented approach has been
applied to a railway interlocking system, demonstrating its feasibility and
effectiveness in several years of testing experience
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