When we talk about event-driven architectures, we often focus on things like loose coupling, scalability and DDD. But under the hood, the way consumers receive events matters just as much. And it usually comes down to one of two models: push vs poll.
Your choice dictates what service(s) you use and how you handle errors.
So, in this article, let’s compare the two models and understand their pros & cons.
Event-driven architectures encourage loose coupling.
But we are still bound by lessor forms of coupling such as schema coupling. And here lies a question that many students and clients have asked me:
“How do I version my event schemas?”
In this post, let’s run through some common approaches and why they all suck to some degree and the two most important decisions you need to make.
A common challenge in event-driven architectures is the potential for unintentionally triggering downstream consumers when running end-to-end tests.
Ephemeral environments can help, but not when you must publish events to a shared event bus.
In such cases, you can conditionally create a local copy of the event bus as part of the ephemeral environment so your test events will not trigger downstream event consumers.
One under-appreciated aspect of designing an Event-Driven Architecture (EDA) is how much information you should include in your events.
Do you send light events or rich events?
Or perhaps you would send both, but in different circumstances?
In this post, let’s talk about the pros & cons of each and how they fit into my mental model of DDD and EDA.
This article is about best practices for building event-driven architectures on AWS, with a focus on wrapping events in custom envelopes when using EventBridge.
While EventBridge provides metadata by default, a custom envelope allows for a standardized, consistent structure across all of your events, making it easier to manage and evolve the system over time.
By providing your own metadata, you can gain better interoperability between different services, end-to-end observability, idempotency control and versioning.
~~~~~~~~~ UPDATE 02/08/2023: EventBridge Schedule now supports automated deletion upon completion. So the problem and solution discussed in this post is no longer relevant. Please see the announcement here. ~~~~~~~~~ The launch of EventBridge Scheduler was one of the highlights for me for re:Invent 2022. Finally, we have a scalable service that lets us …
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