My TOP Patterns for Event Driven Architecture

Here are my top 5 patterns and concepts (Outbox, Idempotent Consumers, Event Choreography, Orchestration, Retry/Dead Letter) for Event Driven Architecture that you'll likely implement. Why? Well if you're new to Event Driven Architecture there are many different problems that you'll encounter. Most of the issues have well-established patterns or concepts you can leverage to deal with them. Here are the most common patterns for Event Drive Architecture that you'll likely use.

🔗 EventStoreDB

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Reliably Save State & Publish Events (Outbox Pattern)

Handling Duplicate Messages (Idempotent Consumers)

Event Choreography & Orchestration

Handling Failures in Message Driven Architecture

0:00 Intro
0:25 Outbox Pattern
2:38 Idempotent Consumers
4:15 Event Choreography
5:46 Orchestration
7:36 Failures (Dead Letter Queues, Retries)

#eventdrivenarchitecture #microservices #messaging

[toxicitysocks]

Thank you for sharing these! I am trying to really tackle event driven system design and these are some of the best quality discussions I’ve found.

[tomasjablonskis]

Loving the content so far. Would be nice to see more videos about ES + CQRS Query side of things: how they are usually implemented; types of queries (single get; subscribing to projection updates; etc.); where are projections cached for query handlers to consume and how query handlers access them; and in general it would be nice to see the whole orchestration between UI and projections (UI getting notified because of persisted projection change (Command -> Handler -> Rebuild aggregate from repo -> Change aggregate -> Aggregate publishes event -> Projection updates (persisted? in-memory?) -> UI gets new data update through some sort of stream/subscription -> ...), etc.).

[glaydersen]

Thanks for this video! This is the kind of video that everybody should rewatch every other week! :D

[LuisRuizHalo]

I’ve been following you since earlier this year. Still amazed by your content. Thank you!

[driden]

What a great video, the amount of info in this one is awesome.
Congratulations and thank you for posting it!

[saranshd.]

I have a questions regarding the outbox pattern. If the publisher is constantly checking for new messages stored in the database, wouldn't it become similar to polling as in a request/response system? What would be the benefit of event driven architecture there?
Very informative video btw.

[ryanelfman]

The inbox/outbox pattern seems very chatty. Have you ever run into perf/scalability issues with this? It seems a bit redundant writing the message to the database as well as the broker, but I get why (at least once delivery). Why not write to the broker and the consumer then writes the state to the database after the message has been picked up?

[jppatter]

Fantastic summary video and your separate videos on each topic have all been very helpful.
What are your thoughts on MassTransits implementation of the outbox pattern being in memory only? Is it a viable solution for this problem?

[prasadhkumarjadhav]

Hey Derek first of all thanks for all your efforts i enjoy your videos content. I request an clarification from you. I would like hear from you about how to design asynchronous microservice system, a little direction about what patterns or tools are involved would help, for e.g how does. An ecommerce system does order processing there should be lot of large background procesing involved like user order validation, inventory checks, logistics processes all happening together when we simply click on place order ...how does one design an microservice system which involves large background processings

[imranhussain]

Thank you vey much for posting an amazing content and most importantly to the point and with demo.
I am watching your videos for coupe of weeks now, I am really enjoying.
One question, on Outbox and Inbox pattern. Sine we are introducing Database (to store and check duplicate messages), I guess
there will be an impact on throughput?
since consumer need to check the MessageId in same transaction, our business logic will have dependency on the messaging system?
Thanks

[penaplaster]

Does it make sense to have an “inbox” component for each service that will ingest incoming messages, deduplicate those and pass to consumers in the service?
Or perhaps this job can be done by a middleware that is called before executing a message handler. Also, can a sidecar be a deduplicator?

[IvanRicardoLopes]

Question about event driven applications: Do you storage your events as JSON or do you minify it to reduce its size? do you have any video about it?

[mayureshs]

Informative video! Are there any recommended messaging libraries that provide such patterns.

[dennismatveyev]

could you pls tell how is the consumer supposed to be reading from some storage when we have inbox pattern ? thank you!

[MerrionGT]

Orchestration example and the Saga pattern seem very similar - is there a difference between them?

[SL-]

The captions are really messed up for this video, can you please check them out and fix? I need them to watch content. Thanks

[ayushgorya]

In outbox pattern, what if the database is not responding then we have the same issue as broker not available, right?

[GavSaysPogMoThoin]

Great video as always Derek.
I'm a fan of the orchestration pattern; what tech have you used yourself to implement this? All bespoke or any tech in particular?
Others have mentioned MassTransit in the comments. Its concept of Sagas is an implementation of the orchestrator patten, particularly suited to long-running transactions. I've not used it myself but it looks like a great option. Keen to hear your thoughts. Cheers.

[ilyahryapko]

Hey! Cool video! Could you please make video comparison of popular dotnet libraries for messaging? CAP, Brighter, Rebus, Masstransit, NServiceBus, MediatR (joking). I want to start my own pet project with ES but I'm struggling to choose.

Also for the guys here. What's the purpose of Kafka, do I need separate event persistence technology with that? or this is RabbitMQ and EventstoreDB combined?
I only know mediatr and its send/publish scheme of working, is the only difference between this and mentioned before libraries is out process handling? I also quite fear manually serializing and deserializing of my querries and commands and sending them through some sort of message bus, is it normal?

[lucianothomagini]

Have you sny recomendation for C# MediatR to make the Publish(INotification) with some Kafka or RabbitMQ final implementation? I search over your Channel but the near thing was HangFire, but It is not enough cause we are trying implement EDA over the services