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May 8 – 12, 2023
Norfolk Waterside Marriott
US/Eastern timezone

Upgrade of Online Storage and Express-Reconstruction system for the Belle II experiment

May 11, 2023, 11:30 AM
Marriott Ballroom V-VI (Norfolk Waterside Marriott)

Marriott Ballroom V-VI

Norfolk Waterside Marriott

235 East Main Street Norfolk, VA 23510
Oral Track 2 - Online Computing Track 2 - Online Computing


Park, Seokhee (KEK)


The backend of the Belle II data acquisition system consists of a high-level trigger system, online storage, and an express-reconstruction system for online data processing. The high-level trigger system was updated to use the ZeroMQ networking library from the old ring buffer and TCP/IP socket, and the new system is successfully operated. However, the online storage and express-reconstruction system use the old type of data transportation. For future maintainability, we expand the same ZeroMQ library-based system to the online storage and express-reconstruction system. At the same time, we introduce two more updates in the backend system. First, online side raw data output becomes compressed ROOT format which is the official format of the Belle II data. The update helps to reduce the bandwidth of the online to offline data transfer and offline-side computing resource usage for data format conversion and compression. Second, high-level trigger output-based event selection is included in the online storage. The event selection allows more statistics of data quality monitoring from the express-reconstruction system. In the presentation, we show the description and test result of the upgrade before applying it to the beam operation and data taking.

Consider for long presentation No

Primary author


Presentation materials

Peer reviewing