CERN Accelerating science

ATLAS Note
Report number	ATL-DAQ-PROC-2024-005
Title	Web Run Control for ATLAS Trigger and Data Acquisition
Author(s)	Kazarov, Andrei (University of Johannesburg (ZA)) ; Koulouris, Aimilianos (CERN)
Corporate Author(s)	The ATLAS collaboration
Collaboration	ATLAS Collaboration
Publication	2024
Imprint	22 Jul 2024
Number of pages	5
In:	22nd International Workshop on Advanced Computing and Analysis Techniques in Physics Research, Stony Brook, United States, 11 - 15 Mar 2024
Subject category	Particle Physics - Experiment
Accelerator/Facility, Experiment	CERN LHC ; ATLAS
Free keywords	web application ; run control ; data acquisition
Abstract	The ATLAS experiment at the Large Hadron Collider (LHC) operated very successfully from 2008 to 2023. The ATLAS Control and Configuration (CC) software is the core component of the ATLAS Trigger and Data Acquisition (DAQ) system. It encompasses all the software required to configure and control the ATLAS data-taking processes, essentially acting as the glue that holds the various ATLAS sub-systems together. In recent years, more and more CC software applications have become available as web applications, facilitating remote operations for experts. However, the main data-taking control and monitoring application, known as 'Igui' (Integrated Graphical User Interface), was missing. Igui is the front-end GUI tool used by operators in the ATLAS Control Room to manage data-taking sessions. This paper introduces a new web application called 'WebRC' (Web Run Control), which provides Igui-like functionality for monitoring and controlling data taking from a web browser. WebRC features include presenting the Run Control tree of all applications, dynamically updating their states, browsing log files and message streams, and monitoring various system and trigger rates and detector busy information. These features allow experts to promptly assess the state of data taking and investigate potential issues. WebRC is built using the Apache Wicket framework and is a Java-only backend application. A crucial requirement for this choice was the necessity to closely integrate with CC services on the backend side, ensuring high performance and scalability. Wicket leverages standard HTTP and AJAX technologies to achieve dynamic application behavior. Recent developments include integrating WebRC with CERN's authentication infrastructure, enabling actions to be performed on behalf of the user authenticated via CERN's Single Sign-On (SSO) system within a web browser page. This integration allows full user control over TDAQ data-taking sessions, including changes to the DAQ configuration, sending RC commands, and starting and stopping DAQ session processes.