40th Tango Community meeting at ALBA

Scheduling Tango callbacks: Lessons learnt from debugging event-driven Tango at scale

9 Jun 2026, 16:35

20m

Maxwell Auditorium (ALBA Synchrotron)

Talk Community Device Classes, Tools, and Applications Community Device Classes, Tools, and Applications

Speaker

Thomas Ives (Observatory Sciences Ltd)

Description

At SKAO we have a large group of developers building a control system that relies heavily on the Tango event system. Our tests succeed or fail on the delivery of a single event and when that event doesn't come the immediate response is often "Tango events don't work". However, after debugging many the "Tango event system is broken" issues with tools such as ska-tango-event-monitor we have found that these are all "holding it wrong" problems.

Even though the issues we run into aren't fundamental problems with the Tango event system, we still have the problem that there seems to be too many ways to "hold it wrong". This talk explores the pitfalls of the Tango event system that developers at SKAO have run into and introduces our new CallbackScheduler class to try and provide an easier to hold API.