SAGA | Microservices Architecture Patterns | Tech Primers
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- เผยแพร่เมื่อ 20 มิ.ย. 2024
- This video covers 2 different SAGA patterns - Choreography and Orchestration
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#Microservices #SAGA #TechPrimers - แนวปฏิบัติและการใช้ชีวิต
Got selected in an interview only by explaining to this one question bcz of this 👌
Glad it was helpful 😄
That's awesome
Really? Interviewer didnt ask you where is the distributed transaction scenarios here. What he explained is actually food delivery service and partially SAGA pattern.
What happens if payment fails or resturant svc fails etc... SAGA implements the concept of comkit or rollback which he totally skipped in the video
You owe first salary to channel!
@@curiossoul So true. Agreed.
Thanks Tech Primer for the tutorial. Would appreciate more content around microservices
Wonderful explanation! Thank you!
Your explanation was flawless! Thanks in advance for sharing your knowledge
What a explanation, kudos!!!
You know how to get the job done. Great videos as always.
much needed video, since i have been searching how a client request is deserialized and executed by multiple micro services
Awesome....very clear explanation. Thank you so much :)
Very clear, it 'd be great to develop an example with lambdas/spring cloud in AWS
Tanks you. Will glad see the corresponding code
Great video, clearly explained how each microservices interact with each other, better than a lot of other materials I find on the internet
Nice and clean explanation. What we see across multiple forums is explanation on Saga. But not coding example. Would be nice to see coding example for the same example.
The two components to see in coding example will be
1. how microservices handle multithreading (specially for crud operations assuming every microservice has its own database)
2. How data consistency is maintained across these 4 microservices (as per example in video). This one has two elements - first one being every microsrvice has its own database and second one being all have shared database.
well explained! I would talk about distributed transactions and compensation operations for the rollbacks.
@Z3U5 CQRS pattern is not used for distributed transactions SAGA deals with that since it is its common use.
Very well explained. Thanks for the video.
Very helpful video, Thanks
thank you very much
it was really simple and clear
Well explained... Thanks
Great Explanation, Nice thing about your videos is always one step ahead of what Market needs. Really appreciated your skills and service which you are doing ..
Simple & Elegant
Great content ,Thanks for sharing
Nice one.. Thanks for this...!!!
Very nicely explained
Awesome!! Keep up the good work!!!
Nice video..well explained.
Nice video. Ty
an example of orchestrated saga would be nice. thanks in advance 😊
Excellent
thanks... this is awesome
Very good explanation.
Nice explanation and good to learn. Nice Bro
It's an awesome tutorial, Can you please make a video with java based code example will be highly appreciated. Thanks
Nice explaination
Thank youuu
orchestrator pattern introduce the high degree of coupling . please let us explain how compensation event would process ?
Nicely explained SAGA pattern, Can you explain what is the proper way to handle transaction across the distributed micro services?
thanks sir for very nice information
nice video and it's pleasant to listen to you despite some accent
Thanks for the video...
can you please make one video or give some idea on session interaction between microservices like we have in amazon order MS,payment MS, user MS, cart MS interaction using session how they are interacting by keeping identity of same user?
Great Video.. In case of Azure, OrchestrationService would be a WebJob or function; The initial event saga pattern is done via Azure Service Bus and Event handlers...
Any git repo example
Is there any link to source code please?
Yeah and that’s a great way to wire yourself to one cloud environment. Silly idea.
Super.. can you do a video on the coding for the same using SAGA pattern
Sure
He will not do.
Hi Ajay, Waiting to see this in action .
Nice video. Thanks
Fantastic explanation. Thanks so much. Can you please show this at code level? It would been better to see it in action.
Super bro. Can you prepare one spring boot example with SAGA implementation?
There are two points which needs to be added here: 1. In Choreography pattern how the failures are handled 2. In case of Orchestration pattern the request will not come to order-service the request will come to Orchestration service.
Thank you Team. Got clear picture about saga usage. I am implementing it. Yet I have many doubts. When will you release the video on coding part. Please make a video of this implementation.
Thanks for your acknowledgement. Please make video on Saga implementation with .net c#
Thanks nice video . I learn lot of things from u r videos . Could you please make video on session management in microservices please ?
Thanks for the explanation. One question related to Choreography. If Restaurant Service needs a new data introduced in Order Service, is it safe to assume the changes have to be made in Order, Payment and Restaurant services?
Nice video!!!! thanks, for the very nice information and can you help to do video Kubernetes scaling master and slave fail how to do autoscaling...
Very Helpful Man. Thanks
good one and very easy to understand. can you also do one for failure handling / rollbacks scenarios?
Awesome ❤️🔥❤️🔥❤️🔥❤️🔥❤️❤️
Nice explanation
Nice video sir.
Hi. I have few queries on SAGA. Please help me to answer .
1. Here you cover only happy path , if everything works well. What if payment failed. How they roll back from the order services.
2. Do it maintain lock at database level. Say in ecommerce application , i have 5 inventory in stock but 10 users are buying at the exactly same time. ? How data consitency are maintained ?
Nice explanation. Could you pls provide inputs on how orchestration is different from two phase commits .It looks like they both work the same way .
Orchestration does things more than two phase commit
How to handle failures in these patterns, how you will define compensating events
Awesome video, super helpful!
Which tool have you used it for these diagrams/flow - looks wonderful!!
Google slides
@@TechPrimers thanks for your quick reply! Will explore it! Thanks again😊
Where can I see the code examples implemented based on the explanation in this video?
Thx! nice video. You are the best! Please show an example. Need real example with code
What about the rollbacks transactions?This video is really a very nice introductory video.
Nice video. I have a question. In the orchestration approach how the message passing happens between the orchestration service and other micro services? Are they REST API calls which make it a synchronous flow? I assume they are not event based where events are pushed to a message queue and consumed from it for processing.
Correct. If they are pushed to a queue they become event sourcing/ event based architectures
@@TechPrimers thanks for replying. My followup question on both the Choreography and Orchestration will be - What happens if the payment fails due to insufficient balance in user's payment method or due to network issue? In my opinion an order should be created only after payment is completed successfully.
Ayaskant Swain yes. In this case the order need to cancelled so addition message/request will be sent to the necessary microservices to update the state to cancelled
@@ayasswain Initially Order State will be in PENDING state after all the microservices has been executed successfully I mean in this example after delivery service completes Order state is going to be changed to Placed/Processed
Getting this type of questions regularly in interview... thanks for explaining.. please give some coding ideas on this...
sure bimal.
@@TechPrimers Ajay please do a coding session on the same
Thanks
Thanks Ajay for the nice tutorial. I got one question. When you use asynchronous communication between microservices through messages, client or the web frontend won't get response immediately. What is the pattern or technology should be used in that scenario? Is using web sockets a good practise in such scenario?
No Web socket Connections are not suitable here as you don't need client server communication open every time. once client place an order. client will make long http request or delay calls (like in every 2 second to find out the status) to servers and server can respond back with the current status of the transaction. once client find out the terminal state like transaction success or failure, it will not make http request again. It could be one of the solutions.
How about the rollback service if the payment fails or if there is a problem with delivery?
Use Camuda workflow engine for build sagas. Spring has starter for Camuda.
good explanaion about those patterns but motivation is missing. Also in orchestration pattern, does Orchestrater makes sync api call to each service and gets the response or it sends an event and receives an event as a response?
Why in the Orchestration option the initial request is not sent to the orchestration service instead of the order service?
Simply put. Thanks.
In Choreography pattern, What would happen if Payment service succeeds but Restaurant service refuses for some reason?
I assume Payment service will have to listen for the failed event and start Payment reversal process - Compensating Transaction. Any other better way?
Hi Sir one question. How to handle transaction in case of cassandra database. and if we are following database per service pattern.
Thanks in advance.
Hi Ajay , there is a straight forward issue i could see with the above design .Suppose I have ordered 2 items from a Particular resturant and Payment has been completed for 2 items and when request reached to Resturant service it is able to process item1 and deny item2 because of some issue(lets say ingredient is not available) . How I am gonna make the payment reverse in this case.
is there a good book to learn all consistency concepts in micro services..?
You could have added the context of transaction where we mainly use the SAGA pattern. But I always like your videos
It would be really helpful even more if you cover the failure scenarios and roll backs how its gonna handle. Services should build on keeping failure scenarios in mind. Happy flow anyways doesn't challenge the distributed transaction management
There is a Part 2 video with failure handling, take look at that. I uploaded it few days ago
Here is the link for Part 2 th-cam.com/video/a8RM2xCM9RY/w-d-xo.html
Sir can you create a vedio on Microservice architecture pattern CQRS implemented using spring boot
You are saying common queue it means each MS are reading message from queue then in this case order created event could be read any of the services
one quick observation, you are using message and event interchangeably, this can be misleading as messages and event are different, otherwise i feel this is a very good presentation, keep up the good work.
In case one of the services fail, how does the orchestration service maintain transaction integrity?
The same as Choreography approach, expect the orchestrator is calling the service. Every step in the first phase of a saga has a rollback (they call it "compensating") action, so it's on the orchestrator to call services in the pervious steps to initiate a rollback action. For example in his diagram, if payment failed the orchestrator calls the order service notifying of a payment failure and the order service action would be to updates the order status to "payment failed"
how will handle the exception in both patterns ?.... specially in event based pattern,
What kind of exceptions
Can we have code implementation for this
Pls do the video on saga implementation
sure will do
After payment service updated the db what if order service failied , how it will rollback the payment service changes ?
what happen when central service goes down?
In case of event base, what will happen when queue goes down, then how will they interact?
nice video orchestration is little messy and orchestrator might eat all the resource.instead of this use a flag based approach in database and constantly check if changes are committed to database by quartz it will remove orchestrator and make it lightweight.
but that means we are going with shared db pattern. What if I have 12 microservices with 1000 transactions a second. Can't put load on DB so much to understand what everyone has to do next.
Could you please help how can we maintain “transaction” where multiple microservices are communicating to each other?
What if one of them fails during the transaction? How to roll back the persisted data or transaction in other microservices?
Could you please make a CODING tutorial on Saga (Orchestration/Choreography pattern)? It will be of great help.
I search a lot for such kind of online tutorials but it’s not available anywhere over internet.
Hi, have you found any coding tutorial on saga? If yes, can you please give me the video or website link?
if you have a transaction failed you emit out the event in asynchronous queue and other micro services will get this event and can rollback in its own database.
Suppose if I want to cancel order then how I do in case of orchestration
Thank's for the video bro, if possible please make video on webflux with aop logging, time calculation. Ur doing unique videos, this one also going to be unique. Thanks in advance bro
Please share link of saga implementation
Can you please make a video on this with coding example and live working of it through code.. I am unable to find any coding video on internet
I have one query regarding choreography approach.
If any event published then all linked micro services will be triggered but only micro service will execute logic which matches the event action. is that correct ?
Not necessarily. It's upto us, how it can be implemented. If we use rabbitmq, we can do filtering at the rabbitmq level. If we use kafka, we will have to filter unnecessary messages at app level. We can chose either approach
@@TechPrimers Thanks
A question about orchestrated pattern:
In this pattern does orchestrator service call payment and delivery service synchronously or via a event?
You can do either. When you do with event it evolves to event sourcing
@@TechPrimers Bit confused here, Event sourcing is used if I have to create my current state from sequence of events and my events will be persisted in event store say Kafka.
How that will be used for distributed transaction pattern like orchestrated saga
Your reply all already has the answer.
Irrespective of which implementation (SAGA) you use, event sourcing is going to help recover your state. So why not SAga
@@TechPrimers hmmm...make sense Thanks for the help🙏
One more thing if you could create a video with Orchestrated Saga that would really help us. Thanks in advance 😊
Which pattern is better? What are the pros and cons?
Hey I have implemented Saga Orchestrator approach as I find it bit better for following reasons:
* It maintains SAGA logs at one place by default which is very helpful for debugging and tracing purpose
* Unlike Choreography, Not much documentation required and any new developer can get complete understanding by looking at saga orchestrator, as all the api calls/push are happening from there only.
* We can also make use of both (http calls and Event Bus) for calling different micro services from coordinator/orchestrator
I think it’s wrong , SEC is associated to choreograph and not orchestrate .. I think you explanation is correct for choreography and not orchestrating, because in orchestration each service is responsible for its own compensation, please correct me if I am wrong as other blogs says different
Could you please help with coding part I am regularly watching your videos helping a lot
What about the transaction rollback or anything bad happened duration the call ?
Check the part 2 for the compensating transaction
How do you handle failure w/ the saga pattern?
There is a Part 2 video on compensating transactions. You can take a look at that
If any exception occurs during the transaction say in restuarant service then how Order service will be reverting all the transactions including payments?
Cheek the part 2 of this video, i have explained it there
But not every time we have to complete payment before placing the order . There is a facility in Uber Eats where we can pay by cash also.
yes. thats a new feature request :)
Is it possible to have event based orchestration?
Yes it's possible.
Are these patterns used to maintain concurrency among the microservices??
its used in microservices devlopment in transactions
@@kousiks2395 for concurrency between different instances of same microservice?
nope. different microservice
Ok, so how to maintain concurrency between different instances of same microservice.