Architecture of the data aggregation and streaming system for the European Spallation Source neutron instrument suite

TL;DR

This paper presents the architecture of a scalable, event-based data aggregation and streaming system for neutron instruments at the European Spallation Source, integrating open source and custom components for improved data handling.

Contribution

It introduces a flexible, Apache Kafka-based system architecture for real-time data and metadata streaming at neutron facilities, replacing legacy solutions.

Findings

Demonstrated system integration and scalability through test results.

Achieved real-time data streaming with high performance.

Facilitated data and metadata synchronization for neutron experiments.

Abstract

The European Spallation Source (ESS) will provide long neutron pulses for experiments on a suite of different instruments. Most of these will perform neutron data acquisition in event mode, i.e. each detected neutron will be characterised by one absolute timestamp and pixel identifier pair. Slow controls metadata from EPICS, such as sample environment measurements and motor positions, will also be timestamped at their source, so that all data and metadata are streamed as a list of events instead of histograms. A flexible data aggregation and streaming system is being developed combining both open source third-party software and in-house development. This is to be used at ESS and other neutron scattering facilities like ISIS and SINQ, replacing legacy solutions by a shared software collection maintained by a cross-facility effort. The architecture of the Apache Kafka-based system, its metadata forwarding and NeXus file writing components are presented, along with test results demonstrating their integration and the scalability in terms of performance.