An analysis of the control hierarchy modeling of the CMS detector control system

The supervisory level of the Detector Control System (DCS) of the CMS experiment is implemented using Finite State Machines (FSM), which model the behaviours and control the operations of all the sub-detectors and support services. The FSM tree of the whole CMS experiment consists of more than 30.000 nodes. An analysis of a system of such size is a complex task but is a crucial step towards the improvement of the overall performance of the FSM system. This paper presents the analysis of the CMS FSM system using the micro Common Representation Language 2 (mcrl2) methodology. Individual mCRL2 models are obtained for the FSM systems of the CMS sub-detectors using the ASF+SDF automated translation tool. Different mCRL2 operations are applied to the mCRL2 models. A mCRL2 simulation tool is used to closer examine the system. Visualization of a system based on the exploration of its state space is enabled with a mCRL2 tool. Requirements such as command and state propagation are expressed using modal mu-calculus and checked using a model checking algorithm. For checking local requirements such as endless loop freedom, the Bounded Model Checking technique is applied. This paper discusses these analysis techniques and presents the results of their application on the CMS FSM system

Studies of future readout links for the CMS experiment

The S-LINK64 extension (Simple Link Interface 64 bit) is a specification introduced by the CMS (Compact Muon Solenoid) experiment that defines a protocol, electrical interface and form factor for a point-to-point, high-speed 64-bit data link. It does not specify the implementation of the physical link. It extends the S-LINK specification developed at CERN. CMS developed an electrical implementation of this link operating at 400 MB/s in order to read out the detector. This paper studies a possible replacement of the existing S-LINK64 implementation by an optical link, based on 10 Gigabit Ethernet. The new link will employ commercial protocols in order to be able to receive the data by standard hardware components like PCs or network switches. Currently prototypes using multiple Gigabit Ethernet links are being developed and tested. The paper summarizes the status of these studies

Winventory: microservices architecture case study

In the CERN laboratory, users have access to a large number of different licensed software assets. The landscape of such assets is very heterogeneous including Windows operating systems, office tools and specialized technical and engineering software. In order to improve management of the licensed software and to better understand the needs of the users, it was decided to develop a Winventory application. The Winventory is a tool that gathers and presents statistics of software assets on CERN Windows machines and facilitates interaction with their individual users. The system was built based on microservices architecture pattern, an increasingly popular approach to web application development. The microservices architecture pattern separates the application into multiple independently deployable units that can be individually developed, tested and deployed. This paper presents the microservices architecture and design choices made in order to achieve a modern, maintainable and extensible system for managing licensed software at CERN

Windows Terminal Servers Orchestration

Windows Terminal Servers provide application gateways for various parts of the CERN accelerator complex, used by hundreds of CERN users every day. The combination of new tools such as Puppet, HAProxy and Microsoft System Center suite enable automation of provisioning workflows to provide a terminal server infrastructure that can scale up and down in an automated manner. The orchestration does not only reduce the time and effort necessary to deploy new instances, but also facilitates operations such as patching, analysis and recreation of compromised nodes as well as catering for workload peaks

CERN AppStore: Development of a multi-platform application management system for BYOD devices at CERN

The number of BYOD continuously grows at CERN. Additionally, it is desirable to move from a centrally managed model to a distributed model where users are responsible for their own devices. Following this strategy, the new tools have to be provided to distribute and - in case of licensed software - also track applications used by CERN users. The available open source and commercial solutions were analyzed and none of them proved to be a good fit for CERN use cases. Therefore, it was decided to develop a system that could integrate various open source solutions and provide desired functionality for multiple platforms, both mobile and desktop. This paper presents the architecture and design decisions made to achieve a platform-independent, modern, maintainable and extensible system for software distribution at CERN

Winventory: microservices architecture case study

In the CERN laboratory, users have access to a large number of different licensed software assets. The landscape of such assets is very heterogeneous including Windows operating systems, office tools and specialized technical and engineering software. In order to improve management of the licensed software and to better understand the needs of the users, it was decided to develop a Winventory application. The Winventory is a tool that gathers and presents statistics of software assets on CERN Windows machines and facilitates interaction with their individual users. The system was built based on microservices architecture pattern, an increasingly popular approach to web application development. The microservices architecture pattern separates the application into multiple independently deployable units that can be individually developed, tested and deployed. This paper presents the microservices architecture and design choices made in order to achieve a modern, maintainable and extensible system for managing licensed software at CERN

Chopin Management System: improving Windows infrastructure monitoring and management

CERN Windows server infrastructure consists of about 650 servers. The management and maintenance is often a challenging task as the data to be monitored is disparate and has to be collected from various sources. Currently, alarms are collected from the Microsoft System Center Operation Manager (SCOM) and many administrative actions are triggered through e-mails sent by various systems or scripts. The objective of the Chopin Management System project is to maximize automation and facilitate the management of the infrastructure. The current status of the infrastructure, including essential health checks, is centralized and presented through a dashboard. The system collects information necessary for managing the infrastructure in the real-time, such as hardware configuration or Windows updates, and reacts to any change or failure instantly. As part of the system design, big data streaming technologies are employed in order to assure the scalability and fault-tolerance of the service, should the number of servers drastically grow. Server events are aggregated and processed in real-time through the use of these technologies, ensuring quick response to possible failures. This paper presents details of the architecture and design decisions taken in order to achieve a modern, maintainable and extensible system for Windows Server Infrastructure management at CERN

Chopin Management System: improving Windows infrastructure monitoring and management

CERN Windows server infrastructure consists of about 650 servers. The management and maintenance is often a challenging task as the data to be monitored is disparate and has to be collected from various sources. Currently, alarms are collected from the Microsoft System Center Operation Manager (SCOM) and many administrative actions are triggered through e-mails sent by various systems or scripts. The objective of the Chopin Management System project is to maximize automation and facilitate the management of the infrastructure. The current status of the infrastructure, including essential health checks, is centralized and presented through a dashboard. The system collects information necessary for managing the infrastructure in the real-time, such as hardware configuration or Windows updates, and reacts to any change or failure instantly. As part of the system design, big data streaming technologies are employed in order to assure the scalability and fault-tolerance of the service, should the number of servers drastically grow. Server events are aggregated and processed in real-time through the use of these technologies, ensuring quick response to possible failures. This paper presents details of the architecture and design decisions taken in order to achieve a modern, maintainable and extensible system for Windows Server Infrastructure management at CERN

Samba and CERNBox: Providing online access to Windows-based users at CERN

This paper presents the experience in providing CERN users with direct online access to their EOS/CERNBox-powered user storage from Windows. In production for about 15 months, a High-Available Samba cluster is regularly used by a significant fraction of the CERN user base, following the migration of their central home folders from Microsoft DFS in the context of CERN’s strategy to move to open source solutions. We describe the configuration of the cluster, which is based on standard components: the EOS-backed CERNBox storage is mounted via FUSE, and an additional mount provided by CephFS is used to share the cluster’s state. Further, we describe some typical shortcomings of such a setup and how they were tackled. Finally, we show how such an additional access method fits in the bigger picture, where the storage is seamlessly accessed by user jobs, sync clients, FUSE/Samba mounts as well as the web UI, whilst aiming at a consistent view and user experience