Prompt calibration automation at Belle II

Abstract

The Belle II detector began collecting data from e+e− collisions at the SuperKEKB electron-positron collider in March 2019. Belle II aims to collect a data sample 50 times larger than the previous generation of B-factories. For Belle II analyses to be competitive it is crucial that calibration payloads for this data are calculated promptly prior to data reconstruction. To accomplish this goal a Python plugin package has been developed based on the open-source Apache Airflow package; using Directed Acyclic Graphs (DAGs) to describe the ordering of processes and Flask to provide administration and job submission web pages. DAGs for calibration process submission, monitoring of incoming data files, and validation of calibration payloads have all been created to help automate the calibration procedure. Flask plugin classes have been developed to extend the built-in Airflow administration and monitoring web pages. Authentication was included through the use of the pre-existing X.509 grid certificates of Belle II users.