Configuration Management System Research Articles

The CMS online cluster: IT for a large data acquisition and control cluster

The CMS online cluster consists of more than 2000 computers running about 10000 application instances. These applications implement the control of the experiment, the event building, the high level trigger, the online database and the control of the buffering and transferring of data to the Central Data Recording at CERN. In this paper the IT solutions employed to fulfil the requirements of such a large cluster are revised. Details are given on the chosen network structure, configuration management system, monitoring infrastructure and on the implementation of the high availability for the services and infrastructure.

소프트웨어 형상관리와 작업공간의 통합을 통한 산출물의 추적성 향상 기법

소프트웨어 형상관리를 통한 소프트웨어 개발 생산성 및 품질의 향상은 체계적이고 일관성 있는 변경 관리에 기반한다. 변경 관리에 있어 형상항목으로 식별된 산출물은 조직 구성원들에게 그 변경 이력을 제공해야 하며 이를 통해 구성원들은 해당 산출물에 대한 변경을 정확히 추적할 수 있어야 한다. 일반적인 소프트웨어 형상관리 시스템들은 산출물에 대한 추적 정보를 형상관리 시스템 내에서만 제공하고 있으며 개인의 작업공간에서 발생한 개별적인 변경까지 추적하는 기능을 제공하지 못하고 있다. 본 논문은 형상관리 시스템과 개인의 작업공간을 통합함으로써 형상항목뿐만 아니라 개인에 의한 산출물의 변경까지 추적할 수 있도록 하였다. 통합 환경을 통해 형상항목의 수정버전(revision)을 작업공간의 산출물 버전에 태그로 연결시켰으며 두 환경 사이의 연계된 변경 과정에서 추적성 정보의 효율적인 관리를 가능하게 하였다. Software productivity and quality improvement through software configuration management is based on organized and consistent change management. In change management, artifact identified as configuration item should be able to provide its changed history to the members in group and the members should be able to track down the changes made for the corresponding artifact. General software configuration management systems provide tracking information for artifacts only within the configuration management system, and it does not go further to changes that occur within personal working space. This paper provides a solution that helps tracking down changes that occur not only in configuration management, but also personal artifact's changes through the integration of configuration management system and personal working space. A revised version in configuration management system is connected to the artifact version of the working space by the tagging technique, and traceability can be managed more effectively by sharing the tracking information.

An Empirical Approach to Performance Criteria for Manipulation

Empirical performance criteria based on geometric and physical properties are commonly used for real-time decision-making (and design) of redundant anthropomorphic manipulators (serial) or workcells (parallel) performing high level tasks while avoiding obstacles, providing safety, and responding to human commands. This requires configuration management of these complex systems by prioritizing candidate configurations relative to quantifiable secondary objectives with clear physical meanings. Clarity is addressed by using position, inertial, kinetic, and potential energy (gravity and deformation) based metrics that are crisply defined from system and input parameters. Scaling differences among derived performance metrics require normalization to determine their relative import and inclusion in multicriteria decision-making techniques. Large dimensional spaces mean statistically reduced representations are necessary to decipher their relative import and allow an operator without extensive robotic knowledge to use them effectively and independent of a redundancy resolution technique (RRT). We propose two global norms: the unit norm and the average norm for a broad set of performance criteria that quantify these systems’ unique constraint, transmission, and energy characteristics. These norms are then used to select relevant criteria for operational decision-making based on intuitive operator commands instead of abstract mathematical notions. Additionally, a modified RRT is presented that is more robust with respect to changes during operation in the secondary objectives, which allows for greater flexibility when formulating new criteria. Results are illustrated using a variety of new and existing criteria on an anthropomorphic dual-arm system.

Configuration management at massive scale: system design and experience

The development and maintenance of network device configurations is one of the central challenges faced by large network providers. Current network management systems fail to meet this challenge primarily because of their inability to adapt to rapidly evolving customer and provider-network needs, and because of mismatches between the conceptual models of the tools and the services they must support. In this paper, we present the Presto configuration management system that attempts to address these failings in a comprehensive and flexible way. Developed for and used during the last 5 years within a large ISP network, Presto constructs device-native configurations based on the composition of configlets representing different services or service options. Configlets are compiled by extracting and manipulating data from external systems as directed by the Presto configuration scripting and template language. We outline the configuration management needs of large-scale network providers, introduce the PRESTO system and configuration language, and reflect upon our experiences developing PRESTO configured VPN and VoIP services. In doing so, we describe how PRESTO promotes healthy configuration management practices.

Applying the integrated E-configuration management systems to improve logistics engineering

The purpose of this paper is to show that the integrated electronic configuration management systems (E-CMS) can be applied to integrate logistics engineering (LE) and improve partner relationship on the logistics pipeline. This paper is based on conceptual framework of the E-CMS developed by previousresearchers applied with information tech1 nology (IT). The E-CMS have been successfully provided an application on the shipbuilding program in Chain Sh pbuilding Cooperation (CSBC). Based on the integrated E-CMS, this paper proposes a model in acquisition of logistics demands through the integrated operation systems including end users, depot and suppliers. To evaluate the effectiveness of the E-SCM, this research based on the model, proposed by Wilson and Jantrania (1996), of conceptualizing relationship value to develop a questionnaire. Meanwhile, applying varimax rotated factor analysis determined the underlying variables of the E-CMS benefits. It points out the logistics pipeline from an original initiative through the redesign integration systems to effectively increase in performance of shipbuilding project management

Combined application of Product Lifecycle and Software Configuration Management systems for ITER remote handling

The advantages of Product Lifecycle Management (PLM) systems are widely understood among the industry and hence a PLM system is already in use by International Thermonuclear Experimental Reactor (ITER) Organization (IO). However, with the increasing involvement of software in the development, the role of Software Configuration Management (SCM) systems have become equally important. The SCM systems can be useful to meet the higher demands on Safety Engineering (SE), Quality Assurance (QA), Validation and Verification (V&V) and Requirements Management (RM) of the developed software tools. In an experimental environment, such as ITER, the new remote handling requirements emerge frequently. This means the development of new tools or the modification of existing tools and the development of new remote handling procedures or the modification of existing remote handling procedures. PLM and SCM systems together can be of great advantage in the development and maintenance of such remote handling system. In this paper, we discuss how PLM and SCM systems can be integrated together and play their role during the development and maintenance of ITER remote handling system. We discuss the possibility to investigate such setup at DTP2 (Divertor Test Platform 2), which is the full scale mock-up facility to verify the ITER divertor remote handling and maintenance concepts.

The SmartFrog configuration management framework

SmartFrog is a framework for creating configuration-driven systems. It has been designed with the express purpose of making the design, deployment and management of distributed component-based systems simpler and more robust. Over the last decade it has been the focus for ongoing research into aspects of configuration management and large-scale distributed systems, providing a platform for experimentation. The paper covers the rationale for the design of the framework, details of its design, plus a description of the further research that is in progress.

Identifying exogenous drivers and evolutionary stages in FLOSS projects

The success of a Free/Libre/Open Source Software (FLOSS) project has been evaluated in the past through the number of commits made to its configuration management system, number of developers and number of users. Most studies, based on a popular FLOSS repository (SourceForge), have concluded that the vast majority of projects are failures. This study’s empirical results confirm and expand conclusions from an earlier and more limited work. Not only do projects from different repositories display different process and product characteristics, but a more general pattern can be observed. Projects may be considered as early inceptors in highly visible repositories, or as established projects within desktop-wide projects, or finally as structured parts of FLOSS distributions. These three possibilities are formalized into a framework of transitions between repositories. The framework developed here provides a wider context in which results from FLOSS repository mining can be more effectively presented. Researchers can draw different conclusions based on the overall characteristics studied about an Open Source software project’s potential for success, depending on the repository that they mine. These results also provide guidance to OSS developers when choosing where to host their project and how to distribute it to maximize its evolutionary success.

Configuration Management for Large-Scale Scientific Computing at the UK Met Office

The UK Met Office's flexible configuration management (FCM) system uses existing open source tools, adapted for use with high-performance scientific Fortran code, to help manage evolving code in its large-scale climate simulation and weather forecasting models. FCM has simplified the development process, improved team coordination, and reduced release cycles.

NixOS

Existing package and system configuration management tools suffer from an imperative model , where system administration actions such as upgrading packages or changes to system configuration files are stateful: they destructively update the state of the system. This leads to many problems, such as the inability to roll back changes easily, to run multiple versions of a package side-by-side, to reproduce a configuration deterministically on another machine, or to reliably upgrade a system. In this paper we show that we can overcome these problems by moving to a purely functional system configuration model . This means that all static parts of a system (such as software packages, configuration files and system startup scripts) are built by pure functions and are immutable, stored in a way analogously to a heap in a purely function language. We have implemented this model in NixOS , a non-trivial Linux distribution that uses the Nix package manager to build the entire system configuration from a purely functional specification.

High level trigger configuration and handling of trigger tables in the CMS filter farm

The CMS experiment at the CERN Large Hadron Collider is currently being commissioned and is scheduled to collect the first pp collision data in 2008. CMS features a two-level trigger system. The Level-1 trigger, based on custom hardware, is designed to reduce the collision rate of 40 MHz to approximately 100 kHz. Data for events accepted by the Level-1 trigger are read out and assembled by an Event Builder. The High Level Trigger (HLT) employs a set of sophisticated software algorithms, to analyze the complete event information, and further reduce the accepted event rate for permanent storage and analysis. This paper describes the design and implementation of the HLT Configuration Management system. First experiences with commissioning of the HLT system are also reported.

결함 추적 시스템에 의한 소프트웨어 결함 분석 및 관리기법 연구

프로젝트 진행중에 발견하지 못한 결함이 소프트웨어 개발 완료 후 유지보수 단계에서 발견되는 경우가 많이 있다. 유지보수 단계에서 결함의 발생 빈도가 높을수록 비용은 증가하고 품질은 저하되며 고객의 신뢰성을 떨어뜨린다. 결함은 조직에서 발생에 대한 원인 분석 및 프로세스 개선이 지속적으로 이루어지지 않으면 감소하지 않는다. 본 논문에서는 파레토 법칙에 따라 결함은 이미 발생된 유형이 반복되어 전체 결함 유형의 대부분을 차지한다는 점에 감안하여 DTS를 구현하였다. DTS는 유지보수 단계에서 과거에 발생했던 결함 유형의 이력을 바탕으로 결함의 원인을 추적하여 개발자, 운영자 및 유지보수 담당자에게 개선을 위한 근본 데이터를 제공함으로써 같은 유형의 결함이 반복적으로 발생하지 않도록 최대한 지원해 준다. DTS의 기본 활동은 프로그램의 결함유형 분석 및 측정 지표를 제공하고, 프로그램별 결함 유형을 집계한다. 이렇게 측정된 결함의 유형 사례를 해당 업무 팀에서 확인함으로써 지속적으로 결함을 개선할 수 있도록 지원한다. W사의 프로그램 형상관리 시스템에서 DTS를 구현하고 적용한 결과 약 65%정도의 결함이 개선되었다. The software defects that are not found in the course of a project frequently appear during the conduct of the maintenance procedure after the complete development of the software. As the frequency of surfacing of defects during the maintenance procedure increases, the cost likewise increases, and the quality and customer reliability decreases. The defect rate will go down only if cause analysis and process improvement are constantly performed. This study embodies the defect tracking system (DTS) by considering the Pareto principle: that most defects are repetitions of defects that have previously occurred. Based on the records of previously occurring defects found during the conduct of a maintenance procedure, DTS tracks the causes of the software defects and provides the developer, operator, and maintenance engineer with the basic data for the improvement of the software concerned so that the defect will no longer be manifested or repeated. The basic function of DTS is to analyze the defect type, provide the measurement index for it, and aggregate the program defect type. Doing these will pave the way for the full correction of all the defects of a software as it will enable the defect correction team to check the measured defect type. When DTS was applied in the software configuration management system of the W company, around 65% of all its software defects were corrected.

Effective Software Merging in the Presence of Object-Oriented Refactorings

Current text based Software Configuration Management (SCM) systems have trouble with refactorings. Refactorings result in global changes which lead to merge conflicts. A refactoring-aware SCM system reduces merge conflicts. This paper describes MolhadoRef, a refactoring-aware SCM system and the merge algorithm at its core. MolhadoRef records change operations (refactorings and edits) used to produce one version, and replays them when merging versions. Since refactorings are change operations with well defined semantics, MolhadoRef treats them intelligently. A case study and a controlled experiment show that MolhadoRef automatically solves more merge conflicts than CVS while resulting in fewer merge errors.

Evolutionary Success of Open Source Software: an Investigation into Exogenous Drivers

The “success” of a Free/Libre/Open Source Software (FLOSS) project has often been evaluated through the number of commits made to its configuration management system, number of developers and number of users. Based on Source- Forge, most studies have concluded that the vast majority of projects are failures. This paper argues that the relative success of a FLOSS project can depend also on the chosen forge and distribution. Given a random sample of 50 projects contained within a popular FLOSS forge (Debian, which is the basis of the successful Debian distribution), we compare these with a similar sample from SourceForge, using product and process metrics, such as size achieved and number of developers involved. The results show firstly that, depending on the forge of FLOSS projects, researchers can draw different conclusions regarding what constitutes a successful FLOSS project. Secondly, the projects included in the Debian distribution benefit, on average, from more evolutionary activity and more developers than the comparable projects on SourceForge. Finally, the Debian projects start to benefit from more activity and more developers from the point at which they join this distribution.

Managing Software Architectural Evolution at Multiple Levels of Abstraction

Software development is a dynamic process where engineers constantly modify and refine systems. As a consequence, system architecture evolves over time. Software architectural evolution has been managed at different abstraction levels: the meta level, the architectural level, the application level, and the implementation level. However, management supports for architectural evolution are limited to evolution mechanisms in architectural description languages such as subtyping, inheritance, interface, and genericity. This paper presents a model-oriented version and configuration control approach to managing the evolution of architectural entities and relationships among them in configurations at different levels of abstraction. This paper also illustrates our approach in building an architectural configuration management system, MolhadoArch, that is capable of managing configurations and versions of software architecture across multiple levels of abstraction in a uniform and tightly connected manner. In MolhadoArch, consistent configurations are maintained not only among source code but also with the high-level software architecture. MolhadoArch supports the management of both planned and unplanned evolution of software architecture. We have conducted an experimental study to show that MolhadoArch can handle large and real-world systems. By evaluation, we learned that the benefits outweigh the extra space needed to represent architectural entities.

System engineering and configuration management in ITER

The construction of ITER will represent a major challenge for the fusion community at large, because of the intrinsic complexity of the tokamak design, the large number of different systems which are all essential for its operation, the worldwide distribution of the design activities and the unusual procurement scheme based on a combination of in-kind and directly funded deliverables. A key requirement for the success of such a large project is that a systematic approach to ensure the consistency of the design with the required performance is adopted. Also, effective project management methods, tools and working practices must be deployed to facilitate the communication and collaboration among the institutions and industries involved in the project. The authors have been involved in the definition and practical implementation of the design integration and configuration control structure inside ITER and in the system engineering process during the selection and optimization of the machine configuration. In parallel, they have assessed design, drawing and documentation management software to be used for the construction phase. Here, they describe the experience gained in recent years, explain the drivers behind the selection of the documents and drawings management systems, and illustrate the scope and issues of the configuration management activities to ensure the congruence of the design, to control and track the design changes and to manage the interfaces among the ITER systems.

Intelligent Reconfiguration of Dynamic Distributed Components

Naming service and the reconfiguration management systems usually work in a client-server manner where both the selection of components and the reconfiguration are a result of a request. Developing intelligent systems that are capable of monitoring and learning about themselves, and thereby rapidly react to changes in their environment, has become essential to most systems. This paper proposes an extension to FRODICA (Framework for Distributed Configurable Applications), a framework that supports the development of non-functional oriented reconfiguration of distributed systems, using the Complex Organic Distributed Architecture (CODA). CODA applies cybernetic concepts such as self-organisation, self-regulation and viability to derive an intelligent architecture, which can react to failures in achieving its objectives and proactively search for successful patterns of behaviour. The result is a configuration management system, which can use the knowledge of itself to proactively and dynamically drive both the search and the reconfiguration of its components.

Visual assessment of software evolution

Configuration management tools have become well and widely accepted by the software industry. Software Configuration Management (SCM) systems hold minute information about the entire evolution of complex software systems and thus represent a good source for process accounting and auditing. However, it is still difficult to use the entire spectrum of information such tools maintain. Currently, significant effort is being done in the direction of mining this kind of software repositories for extracting data to support relevant assessments. In this article we propose a concerted set of visualization tools and techniques for the assessment of software evolution based on the information stored into SCM systems. Firstly, we introduce a generic way to obtain models of source code at different levels of detail and from different perspectives. Secondly, we propose a set of visual representations and techniques to efficiently and effectively depict the evolution of these code models. These techniques target specific questions and assessments, from the detailed code developer perspective to the overview required by system architects and project managers. We detail the concrete implementation of two such code models and corresponding visual representations. The file view describes code change at line level across multiple versions of a single file, or small number of files. The project view shows changes at file level across complete software projects. All our views share the same visual and interactive techniques, enabling users to easily switch among and correlate between them. We implement our visual techniques to quickly and compactly display and navigate the evolution of tens of thousands of artifacts on a single screen. We demonstrate our techniques with several use cases performed on real world, industry-size code bases and outline the concrete findings and ways our visualizations helped in understanding various types of code changes.

Visual data mining and analysis of software repositories

In this article we describe an ongoing effort to integrate information visualization techniques into the process of configuration management for software systems. Our focus is to help software engineers manage the evolution of large and complex software systems by offering them effective and efficient ways to query and assess system properties using visual techniques. To this end, we combine several techniques from different domains, as follows. First, we construct an infrastructure that allows generic querying and data mining of different types of software repositories such as CVS and Subversion. Using this infrastructure, we construct several models of the software source code evolution at different levels of detail, ranging from project and package up to function and code line. Second, we describe a set of views that allow examining the code evolution models at different levels of detail and from different perspectives. We detail three views: the file view shows changes at line level across many versions of a single, or a few, files. The project view shows changes at file level across entire software projects. The decomposition view shows changes at subsystem level across entire projects. We illustrate how the proposed techniques, which we implemented in a fully operational toolset, have been used to answer non-trivial questions on several real-world, industry-size software projects. Our work is at the crossroads of applied software engineering (SE) and information visualization, as our toolset aims to tightly integrate the methods promoted by the InfoVis field into the SE practice.

JDiff: A differencing technique and tool for object-oriented programs

During software evolution, information about changes between different versions of a program is useful for a number of software engineering tasks. For example, configuration-management systems can use change information to assess possible conflicts among updates from different users. For another example, in regression testing, knowledge about which parts of a program are unchanged can help in identifying test cases that need not be rerun. For many of these tasks, a purely syntactic differencing may not provide enough information for the task to be performed effectively. This problem is especially relevant in the case of object-oriented software, for which a syntactic change can have subtle and unforeseen effects. In this paper, we present a technique for comparing object-oriented programs that identifies both differences and correspondences between two versions of a program. The technique is based on a representation that handles object-oriented features and, thus, can capture the behavior of object-oriented programs. We also present JDiff, a tool that implements the technique for Java programs. Finally, we present the results of four empirical studies, performed on many versions of two medium-sized subjects, that show the efficiency and effectiveness of the technique when used on real programs.