Understanding the limitations of pubsub systems

This paper argues that publish-subscribe (pubsub) systems bundle both a messaging abstraction and a hard-state storage layer, and that this hurts their robustness, performance, and correctness for a variety of use cases. Pubsub fails to achieve its central goal of decoupling publishers and subscribers, violates the end-to-end principle, and exposes an ad hoc storage abstraction with a bespoke API and limited power.