Quarkus Community Call - 2026-02-03

[cescoffier]

Hello, Yesterday, we held a deep-dive community call focusing on the "Propagation of Contexts" within Quarkus.

Here is a short summary. You can find the complete minutes (including the recording) on https://docs.google.com/document/d/1TgFZsuOQo9qZ4CnQII5LHhQVgMC6YsVMs1UJIAJooyM/edit?usp=sharing.

Recap:

Julien Ponge then led a masterclass on the complexities of Context Propagation. We discussed the "illusion of simplicity" provided by ThreadLocals and how they break when you move to asynchronous I/O or reactive pipelines. The discussion covered the limits of MicroProfile Context Propagation in non-linear scenarios (fan-in/fan-out) and how Mutiny handles context at the subscription level.

A major point of debate was the use of Vert.x Duplicated Context. Bruno Baptista shared insights into a recent bug involving context cross-talk, prompting a discussion of the need for per-entry duplication policies in the upcoming Vert.x 5 integration. Ladislav Thon warned against using Vert.x context for data scopes shorter than a request and proposed a new initiative: a formal Quarkus Concurrency Model to document exactly what is supported across the stack.

Finally, we touched on Virtual Threads. We evaluated the efficiency of current thread-local patterns versus Java 25's ScopedValue, concluding that we need a pluggable carrier mechanism to address boundaries between execution models.