ARIADNE: a Tracking System for Relationships in LHCb Metadata

20th International Conference on Computing in High Energy and Nuclear Physics

物理学;计算机科学

Shapoval, I.^1,2,3,4 ; Clemencic, M.^1 ; Cattaneo, M.^1

European Organization for Nuclear Research (CERN), Geneva 23

CH-1211, Switzerland^1

Kharkiv Institute of Physics and Technology (KIPT), Akademichna 1, Kharkiv

UA-61108, Ukraine^2

Sezione INFN di Ferrara (INFN-FE), Via Saragat 1, Ferrara

IT-44122, Italy^3

Università di Ferrara (UNIFE), Via Savonarola 9, Ferrara

IT-44121, Italy^4

关键词: Conditions database;    Data processing applications;    Data processing models;    Homomorphic process;    Physics data;    Security issues;    Time-dependent geometry;    Tracking system;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/513/4/042039/pdf
DOI  :  10.1088/1742-6596/513/4/042039

学科分类：计算机科学（综合）

来源: IOP

【 摘 要 】

The data processing model of the LHCb experiment implies handling of an evolving set of heterogeneous metadata entities and relationships between them. The entities range from software and databases states to architecture specificators and software/data deployment locations. For instance, there is an important relationship between the LHCb Conditions Database (CondDB), which provides versioned, time dependent geometry and conditions data, and the LHCb software, which is the data processing applications (used for simulation, high level triggering, reconstruction and analysis of physics data). The evolution of CondDB and of the LHCb applications is a weakly-homomorphic process. It means that relationships between a CondDB state and LHCb application state may not be preserved across different database and application generations. These issues may lead to various kinds of problems in the LHCb production, varying from unexpected application crashes to incorrect data processing results. In this paper we present Ariadne-a generic metadata relationships tracking system based on the novel NoSQL Neo4j graph database. Its aim is to track and analyze many thousands of evolving relationships for cases such as the one described above, and several others, which would otherwise remain unmanaged and potentially harmful. The highlights of the paper include the system's implementation and management details, infrastructure needed for running it, security issues, first experience of usage in the LHCb production and potential of the system to be applied to a wider set of LHCb tasks.