Abstract
ALICE Controls data produced by commercial SCADA system WINCCOA is stored in ORACLE database on the private experiment network. The SCADA system allows for basic access and processing of the historical data. More advanced analysis requires tools like ROOT and needs therefore a separate access method to the archives. The present scenario expects that detector experts create simple WINCCOA scripts, which retrieves and stores data in a form usable for further studies. This relatively simple procedure generates a lot of administrative overhead – users have to request the data, experts needed to run the script, the results have to be exported outside of the experiment network. The new mechanism profits from database replica, which is running on the CERN campus network. Access to this database is not restricted and there is no risk of generating a heavy load affecting the operation of the experiment. The developed tools presented in this paper allow for access to this data. The users can use web-based tools to generate the requests, consisting of the data identifiers and period of time of interest. The administrators maintain full control over the data – an authorization and authentication mechanism helps to assign privileges to selected users and restrict access to certain groups of data. Advanced caching mechanism allows the user to profit from the presence of already processed data sets. This feature significantly reduces the time required for debugging as the retrieval of raw data can last tens of minutes. A highly configurable client allows for information retrieval bypassing the interactive interface. This method is for example used by ALICE Offline to extract operational conditions after a run is completed. Last but not least, the software can be easily adopted to any underlying database structure and is therefore not limited to WINCCOA.
Highlights
The ALICE experiment at CERN [1] is dedicated to the study of ultrarelativistic heavy ion collisions provided by the Large Hadron Collider (LHC)
Most of the values monitored by the Detector Control System (DCS) are stored in a central database for later processing
The access to archived values requires a detailed knowledge of the detector structure, controls implementation and overall design of the distributed system. This knowledge is maintained in the central DCS, but is not accessible to external consumers
Summary
This content has been downloaded from IOPscience. Please scroll down to see the full text. Ser. 513 012015 (http://iopscience.iop.org/1742-6596/513/1/012015) View the table of contents for this issue, or go to the journal homepage for more. Download details: IP Address: 147.232.25.132 This content was downloaded on 02/09/2014 at 12:12 Please note that terms and conditions apply. 20th International Conference on Computing in High Energy and Nuclear Physics (CHEP2013) IOP Publishing. Journal of Physics: Conference Series 513 (2014) 012015 doi:10.1088/1742-6596/513/1/012015. J Jadlovský, A Jadlovská, J Sarnovský, Š Jajčišin, M Čopík, S Jadlovská131, P Papcun, R Bielek, J Čerkala, M Kopčík, P Chochula, A Augustinus Technical University of Košice, Faculty of Electrical Engineering and Informatics, Department of Cybernetics and Artificial Intelligence, Košice, Slovak Republic 2 CERN, the European Organization for Nuclear Research, Geneva, Switzerland
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