Speaker
Description
The ATLAS EventIndex is the global catalogue of all real and simulated data produced and processed by ATLAS. The current implementation, developed and deployed for LHC Run 3 (2022-2026) has to evolve in order to be able to ingest, store and serve the much larger amount of data that will be produced during the High-Luminosity LHC operation years, starting in 2030. The modular architecture of the EventIndex system allows the progressive replacement of components as needed, but the replacement of the core storage system can be seen as a phase transition for the whole environment. By design the EventIndex components are based on open source software developed and used for BigData projects, and this foundation will remain for the future implementation too. Currently the data are stored in HBase tables with a Phoenix interface that allows SQL queries in addition to the native HBase commands; studies are in progress to evaluate the scalability of this solution to HL-LHC rates (three to five times the current rates of data ingestion and query), as well as the possibility to move to alternative data storage solutions. In addition to the ingestion and query performance, a significant factor is the long-term sustainability of the storage solution we will choose, as the system designed in the next couple of years and deployed in 2029 will have to be operational till after the end of LHC Run 4 (2035).