The Saga Pattern in Microservices (EDA - part 2)

Learn about the Saga Pattern in Microservices in order to do distributed transactions, comparing Orchestration vs Choreography.
In this video, the second in the series of Event Driven Architecture, I explain the complexity of doing transactions in distributed systems, specifically in Microservices. Throughout the video I explain how we move from a single system (monolith) to a distributed architecture using Microservices, how to deal with transaction, explain the Saga Pattern with its two variants: Orchestration and Choreography and how they are closely related with Event Driven Architecture (EDA).
For more information on Event Driven Architecture, watch the series: • What is Event Driven A...
#Microservices #SagaPattern
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📘 Recommended books (incentivized):
- Microservices Patterns: amzn.to/337AqjE
- Building Microservices: amzn.to/3h8i0HV
🔖 Relevant resources:
- The many meanings of Event Driven Architecture: • The Many Meanings of E...
- Microservices: martinfowler.com/articles/mic...
- Saga Pattern:
-- Orchestration vs Choreography (microservices.io/patterns/dat...)
-- Pros and Cons: softobiz.com/microservice-orc...
🤓 If you are preparing for a technical interview, don't miss my playlist: devstory.page.link/technical-...
📚 I have also prepared FREE study guides available here (no subscription needed): devstory.page.link/study-guides
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Remember you can reach me here:
#️⃣ Twitter: / cv13lm4
⌨️ Github: github.com/cvielma
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In A Dev' Story I explain Software Development related topics from my point of view. I'll be explaining different topics in "Chapters" according to the stage of the story I think they belong. Hope is as entertaining for you as it's fun for me to create these videos Thanks again for watching! Feel free to like, comment, share and subscribe, it means a lot to me and helps the channel grow.

[@ADevStory]

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[@gabrieldalbo5378]

You know, I’m a Brazilian interpreter, and I work translating software developers’ meetings. Your videos are helping me understand the architecture concepts better and a little bit more on how developers’ minds work. Thank you!

[@ADevStory]

That's awesome ! Glad I could help!By any chance are you interested in contributing the Brazilian translation of some videos?

[@gabrieldalbo5378]

@@ADevStory Hey, yes. Is there any kind of DM here where I can send contact info?

[@ADevStory]

Sure. You can DM me in Twitter: @cv13lm4

[@shrikanthk5445]

Such a simple and straightforward explanation. Clear picture of Saga pattern. THANKS a LOT ...

[@ADevStory]

Glad you found it useful! 😁

[@shubhamjoshi4803]

Is this Steve Jobs teaching Event Driven Architecture? Was very smooth and convincing 😄.

[@ADevStory]

Hahaha thanks. A few _billions_ less rich 😜

[@1986chandru]

Excellent series on the EDA. Thanks a lot for these videos. Wonderful explanations.

[@ADevStory]

Awesome! Wait for the third one in the series. There has been delays but should be out this week or next :)

[@ricardo.93]

Great explanation my friend 👌, I have a better understanding of the SAGA pattern Greetings from Guatemala

[@ADevStory]

Awesome! Glad it helped! :)

[@heenachhabra2977]

I was looking for how to transition from a developer to an architect mindset when I stumbled upon your video series. The series is really useful for me to understand how to think like an architect. It is the simplicity and conciseness of your videos that really make them stand out. Thank you for making such great videos

[@ADevStory]

Oh thanks for the kind words. Glad you found it useful!

[@tasneemwahdan3618]

I am a developer and so interested in architecture and system design. Can you provide more resources to learn and apply these skills?

[@mostinho7]

5:45 orchestration vs coreography. In orchestration, there is a central orchestrator that calls the other services, but in choreography the services listen and react to events

[@anvvsharma873]

great video, good one. all your videos are short, crisp, to-the-point + explaining everything with drawings based on a scenarios

[@ADevStory]

Glad You liked them! Cheers 😁

[@ToeShimmel]

This deserves more views. Your video's are fantastic!

[@ADevStory]

Thank you! Glad you enjoyed it! Feel free to share it everywhere so more people watch it! 😜

[@sadeghrahmani2339]

Simple, to the point, and perfect!

[@ADevStory]

Thank you!

[@flavienrobert2516]

Cristal clear :) Thank you so much, you are a great teacher.

[@ADevStory]

Thank you! Glad you liked it!

[@NomeshDeSilva]

Your way of explanation is awsome . Really helpful 👌🙏

[@ADevStory]

Thanks! 😁

[@reallylordofnothing]

cant believe you helped me revise this in 2 mins. thanks

[@ADevStory]

Glad I could help!

[@soufianer3562]

Simple and straightforward . thx!

[@ADevStory]

Thank you!

[@amazingartsongs5298]

Thank you mate for this great explanation

[@ADevStory]

Glad it was useful!

[@allenprinceton5125]

little fan from Taiwan, thanks for the excellent tutorial

[@ADevStory]

Thank you for your words! Feel free to let me know any content you'd like to see.

[@alexandrutoma9187]

Awesome videos, great content!

[@ADevStory]

Thank you! If you haven't feel free to subscribe. Soon I'll be releasing the last video on this series

[@nooni8624]

Great video! Helped me understand this much better

[@ADevStory]

Glad it helped!

[@ralfrolfen5504]

Very well explained saga pattern! Thank you! #Thankyou

[@ADevStory]

Glad you liked it!

[@danielbracamontes1811]

I liked the video. Just got subscribed to your channel!!

[@ADevStory]

Thank you! Glad you liked it!

[@Kingkiyan24]

Awesome content.. great knowledge share

[@ADevStory]

Thanks!

[@sayitlikeitis1202]

You should be publishing more videos. The way you articulate things is simple and yet Brilliant ! I need to thank you for turning difficult concepts into easy ones to understand and learn

[@ADevStory]

Thank you very much! I will publish some soon! Feel free to suggest any topic :)

[@vb9950]

This is more for Software, and even in Embedded systems EDA (publish-subscribe) model is used. microservices may be more related to software applications but I got some idea on how to work with it.

[@ADevStory]

Yeah event driven architecture also applies to non-distributed systems. Some patterns like the saga one can be simplified though if is not a distributed system

[@liamgryphon7942]

Hey mate, just wanted to say you're awesome! I really love this explaination of EDA. However, have to say the choreography pattern seems so fragile 😱, oh geez. I don't want to ever encounter it.

[@ADevStory]

Hey thanks! Choreography can be useful if there isn't tight coupling between the services, but for transactions, all but the simplest cases are useful to tackle with it. So basically, keep following your intuition 😉

[@gdlmss]

Choreography reminds me a bit how Redux + some middleware like Saga works. Sending actions and hoping some side effect or reducers will listen to it.

[@NomeshDeSilva]

Please do a video about software desiging concepts from basics to advance architecture. Thanks alot ❤️

[@ADevStory]

Sure I can try. What are you looking for? So far I have some about design patterns, OO, and introduction to software architecture. What are you looking for?

[@NomeshDeSilva]

@@ADevStory I would like to learn how to design scalable, performance optimized, low latency systems. from Basic to complex systems by adding advanced concepts would be much appreciated.ex: fault tolerant, resilient, sharding, etc

[@ADevStory]

Have you checked my software architecture introduction series? I cover those topics there albeit very quick and superficial

[@abhilashpatel6852]

So, with event driven architecture, in async communication can we use orchestration or not? or it is only for synchronous communication?

[@ADevStory]

It would be better with orchestration to use synchronous communication. But async can also be used. Keep in mind that if async you still need to have some type of request-reply mechanism in this case.

[@juhairahamed5342]

Good explanation

[@ADevStory]

Thanks! Glad you found it useful!

[@bradydyson65]

I loved the diagramming; that was very helpful for differentiating coreography and orchestration. However, I still don't know how this relates to sagas. Where were the sagas in the diagrams? How many sagas were there? I still don't know what a saga is and I'm trying to figure that out. I think I understand what the "saga pattern" is, but I have no idea what a "saga" is.

[@ADevStory]

I think Saga is also a confusing name but I didn't invent the pattern :P So basically you can translate: Saga = a distributed transaction between microservices. So here's an overview diagram in minute 2:32 (kzbin.info/www/bejne/eWHVeKqvf9B3irc). The Choreography or Orchestration are just ways to implement these transactions. Hope it's clearer!

[@rajatthakur9055]

Just so I am not confused, these SAGA pattern are almost similar to Mediator and Broker Topology in Event Driven Architecture. Or is there a difference? I am confused because here we are taking it up with microservices example.

[@ADevStory]

Really good question! You made me actually investigate a bit since I also got confused. I got torn too here. Best reference I've found is Mark Richards & Neal Ford's Fundamentals of Software Architecture: And Engineering Approach where the authors say that it's basically the same: "Choreography utilizes the same communication style as a broker event-driven archi‐ tecture. In other words, no central coordinator exists in this architecture, respecting the bounded context philosophy. Thus, architects find it natural to implement decou‐ pled events between services." And then for Orchestration explains: "Because microservices architectures don’t include a global mediator like other service-oriented architectures, if an architect needs to coordinate across several serv‐ ices, they can create their own localized mediator[...]" What I gather from the book is that it either is the same pattern in two different architectural styles (EDA and Microservices), which would be cumbersome, or the one I think makes the most sense: Saga pattern can be implemented using EDA's Mediator/Broker topologies, but also can be implemented differently (Orchestration, for example can implement the Saga pattern without using Mediator topology or EDA at all) Hope is clearer, and I'm open for a debate :)

[@rajatthakur9055]

@@ADevStory Thank you for your reply. This makes more sense. Actually, I was reading the book suggested by you - Software Architecture Patterns. After completing the chapter on that I moved to this video of yours on EDA to understand more examples :-). Right now there are no more questions, and I'll continue with reading. But if I have any more will definitely reach out to you. The content you post is really great. Keep creating!! :-)

[@ADevStory]

Glad it helped and that you are enjoying the content! Will try to publish more soon! And feel free to keep shooting questions!

[@goodwish1543]

Thanks for sharing. What is Saga stands for ?

[@ADevStory]

Anytime. Well saga is the name of the pattern, is not an acronym. Here's a full response to that: stackoverflow.com/a/63319683/1238957

[@TheSemenFarada]

Why the Order service does not need to know about the "Order Purchased" event from the payment service? How then the order service will know that order is sucessfull?

[@ADevStory]

It depends on the modeling but the message in the video is that unless you need to rollback some information, you can assume it went ok and the event propagation will take care of it.

[@minhluanvu7918]

Thank you !

[@ADevStory]

You're welcome!

[@chitranshtarsoliya7378]

Hey buddy can you make a video about failure If an event is generated and the services that are listening to that event are crashed The potential reason can be: - A wrong event or missing data in event - service is using other application like (api, db, or 3rd party application) and that application is down temporarily - new version of that service is not Competable The handling can be - reach out to other service to fix that - retry - retry with delays - wait till someone start process manually - rollback build - ignore that request and process other

[@chitranshtarsoliya7378]

I wanna know if there is any pattern for handling these kina situations or how on which metrics we should put conditions to take any actions

[@ADevStory]

Great suggestion! I'm thinking on s new series on of videos on distributed systems and can talk about failure handling.

[@ingenieriamiguens2568]

Thanks a lot. I'm pretty sure that you understand Spanish or maybe Italian hahahaha maybe something In your accent told me that, I'm right?. Anyway, sos un genio!

[@ADevStory]

Jajaja tengo que mejorar el acento 😂 ¡Gracias!

[@ingenieriamiguens2568]

@@ADevStory lo importante es la pronunciación y está perfecta! Question: did you use the AWS solutions to implement this pattern? (Event bridge + step functions) Do you recommend some open source solutions?

[@ADevStory]

I try not to focus on specific implementations, as understanding the pattern gives me more insights into different tech. Having said that, ine specific piece of tech I've analyzed (but haven't used) regarding microservices orchestration is Netflix Conductor (netflix.github.io/conductor/) . It's also fun to see they (rightfully) picked orchestration over choreography because of the shortcomings of choreography.

[@matswessling6600]

move to a room with lesser echo...

[@ADevStory]

Yeah. Technically is reverb (I've been learning since this video 😅) hope you still were able to enjoy the content. The newer videos have better sound

[@matswessling6600]

@@ADevStory reverb is just a lot of echoes... but that is great news.

[@mysocial]

Great stuff but the accent caused replay :D

[@ADevStory]

Thanks! Trying to improve. There's also a curated CC to help with that

[@sdhetan3hetsa]

microservices - most stupid thing I ever heard

[@bastooopanooo2311]

That's why I hate microservices.

[@syd4747]

nah its the best thing