INFORMATION SYSTEM FOR ALICE EXPERIMENT DATA ACCESS J. Jadlovsky, S. Jadlovska, J. Cabala, A. Jadlovska, J. Cerkala, M. Kopcik, M. Oravec, D. Voscek, M. Tkacik, E. Hanc, Technical University of Košice, Košice, Slovakia P. Chochula, P. M. Bond, CERN, Geneva, Switzerland Abstract The main goal of this paper is the presentation of Dcs ARchive MAnager for ALICE Experiment detector conditions data (DARMA), which is the updated version of the AMANDA 3 software currently used within ALICE experiment at CERN [1]. The typical user of this system is either a physicist who performs further analysis on data acquired during the operation of the ALICE detector or an engineer, who analyses the detector status between iterations of experiments. Based on the experience with the current system, the updated version aims to simplify the overall complexity of the previous version, which leads to simpler implementation, administration and portability of the system without sacrificing the functionality. DARMA is realized as an ASP.NET web page based on Model-View- Controller architecture and this paper provides a closer look at the design phase of the new backend structure in comparison to the previous solution as well as the description of individual modules of the system. INTRODUCTION The ALICE experiment studies the ultrarelativistic heavy ion collisions provided by the Large Hydron Collider (LHC). To cope with extreme track densities, many subdetectors based on different technologies have been deployed within ALICE [1]. That is why the ALICE Detector Control System (DCS) has to access many different components and various types of data. A closer look on ALICE DCS can be found in [2], details of the data flow in ALICE DCS are available in [3]. Most of the values monitored by the DCS are stored into the central database, where every detector uses its own schema to prevent possible conflicts. Over the years, many different ways to access the data from this database were used – from the simple client server tool AMANDA to currently used AMANDA 3 package, which allows the concurrent access to DCS archive using multiple clients. Usage of AMANDA 3 brings to light the need of designing the simplified solution with easier implementation and administration and better portability. The acronym DARMA (Dcs ARchive MAnager) was chosen as the name of this information system. Both AMANDA 3 and DARMA were developed by members of CERN and Center of Modern Control Techniques and Industrial Informatics in the Department of the Cybernetics and Artificial Intelligence, Faculty of the Electrical Engineering and Informatics, Technical university of Košice, so in the design of DARMA, experiences from AMANDA 3 development and usage were used and transferred into the latest version. DARMA respects the main features of the AMANDA 3 solution and has been designed to deal with weak spots of its ancestor with focus on improvement of the functionality along with the reduction of its backend structure. AMANDA 3 SOFTWARE OVERVIEW AMANDA 3 is the software solution for the retrieval of the large amounts of DCS data with the main goal of enabling faster access to the multiple users of the system. When compared to previous solutions, AMANDA 3 was designed as a decentralized system, with services running on separate servers in order to deal with the requests traffic and to serve all the users as fast as possible. Windows Communication Foundation (WCF) services system was used to interconnect all decentralized parts of the system to ensure the fast and reliable communication between separate modules. Structure of the AMANDA 3 solution is shown in Figure 1. Figure 1: Structure of AMANDA 3. AMANDA 3 is still used in CERN infrastructure, but with the fast technological changes in IT environment, the development of a new version of the AMANDA 3 was necessary. [4] OVERVIEW OF DARMA The new DARMA solution aims to be simpler and more user-friendly than AMANDA 3, but also retains all the benefits of AMANDA 3. In DARMA, separate services are not considered and the entire solution is implemented in the form of an ASP .NET Web site using the Model – View – Controller (MVC) architecture - Figure 2. 16th Int. Conf. on Accelerator and Large Experimental Control Systems ICALEPCS2017, Barcelona, Spain JACoW Publishing ISBN: 978-3-95450-193-9 doi:10.18429/JACoW-ICALEPCS2017-THPHA041 Data Management and Processing THPHA041 1451 Content from this work may be used under the terms of the CC BY 3.0 licence (© 2017). Any distribution of this work must maintain attribution to the author(s), title of the work, publisher, and DOI.