Applying the Saga Pattern • Caitie McCaffrey • GOTO 2015
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- čas přidán 27. 07. 2024
- This presentation was recorded at GOTO Chicago 2015. #gotocon #gotochgo
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Caitie McCaffrey - Distributed Systems Diva at Twitter @CaitieMcCaffrey
RESOURCES
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github.com/CaitieM20
www.caitiem.com
ABSTRACT
As we build larger more complex applications and solutions that need to do collaborative processing the traditional ACID transaction model using coordinated 2-phase commit is often no longer suitable. More frequently [...]
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Great presentation. Still relevant in 2023 👍
unlike Redux Saga?
Very helpful presentation. Saved me a lot of effort in understanding why and how Saga is used for orchestrating a transaction
Finally, the slides and the video at the same time. Also, excellent presentation. Very knowledgeable.
This talk will be relevant for a while as we all are looking into various ways forms of asynchronous data, multiple data streams, and complex dependencies in transactions . Love this talk !!!!!
what a clear presentation!! Thanks to your talk, i figure out what saga pattern is and could imagine what redux-saga does. Thx again!!
So much comprehensive explanation that irresistibly leads me to understand what saga is
Very clearly and thoroughly explained, thank you.
Fantastic presentation! Thanks
Wonmderful talk! Very articulate and the examples are excellent. Thanks for sharing this.
Nice talk, still valid in 2023. :)
Awesome talk. Thanks for a great presentation
This presentation made Saga's click for me. Nice one.
Awesome Presentation. Very well explained . Thanks !!
That was a great presentation, thank you Caitie
Blown away!!! Thank you :)
Need to learn the Saga Pattern for my first developer job, and this video was certainly a superb starting point!
Seldom does new concepts click as fast and easily as this one did after watching your talk.
Thank you, Caitie!
hi , it's been a year so what other ressources did you use to learn more about saga pattern ? thanks
@@brucewayne2480 microservices pattern, other than that checkout a book by martin kleppmann
Very well explained and practical!
Good talks, well explained. Thanks
Very good presentation, thank you
Very good presentation! Thanks for sharing!
Great to watch at 0.75 speed!
It all depends - worked for me at 1.25
Yep She speaks too fast for non - natives I think :)
@@davidc24994, yes, she does, but she speaks clearly and doesn't swallow words' endings. To my surprise, it was comprehensible. And awesome as well!
lool
Thank a lot for a good explanation of saga. All are clear, even for me
this is a very amazing talk. Thankyou
Very impressive! Interesting topic that was explained and illustrated well and the presentation was right on point.
Excellent talk.
Although it is a bit fast, and some background knowledge is assumed, it's a great presentation ... Thanks !!
What a smart engineer. Well explained! Thanks.
Awesome talk ! Thanks
Very nice talk! Thanks
Great talk. I learnt some new things.
Good job. Thanks,
Fantastic talk
Awesome 👍😀
Fantastic.
Great talk. Thx !
Two questions
1. The presenter says they are using Azure Service Bus as a log. How does this work? I don't understand how a queue would be a useful way to store log information.
2. They mention a "CP log", what does that mean in this context?
My Ears didn't breathe at all watching whole talk 😂
haha thank you! exactly the guidance I needed.
Many thanks 👍👍👍👍
Cool this is workflows and is implemented in things like temporal in 2023. Still wish it were easier to implement but we’re getting there.
Very cool talk. Thanks very much! (:
What if the Saga Log node fails? I think from her presentation, the Saga Log node is not allowed to fail.
15:45 Don't be the person that interrupts someone in the middle of their presentation!
So load data into big bucket and then, at leisure, process and parcel out to store. On fail, retry. This is similar to CQRS except with that the big bucket is kept around and considered to be the database.
Smart!
I don't see the relationship between this and redux-saga, but hey I watched the full thing and maybe, later on, I might come back and laugh at how stupid I was :) great speech.
What techniques did you use to achieve idempotency in your scenarios? - Great talk!
Jeez I was just trying to make ajax calls from my web page. Great talk though !
0.75x speed is perfect!
An excellent presentation, but I have a question, consider T1 for booking hotel runs without problem and we call T2 start, at this moment another service that creates reports for hotels starts to sending new booking records to hotels, but T2 fails and we runs c2 and c1, how should we handle this kind of exceptions?
This report will be eventually consistent, after C1 finishes running. This is my understanding, at least.
@@renatoargh or i think another approach is we will have a third state like 'processing'. And in the happy flow we must send 2 request, one for normal transaction processing, another for converting 'processing' to 'accepted' state. So the report query only use records with the 'accepted' state.
This pattern as I remember is called 'semantic locking' found in the Microservices Patterns book.
This talk is based on the paper 09:03
So if I'm understanding correctly: in order for the Saga to survive the Coordinator dying, either the forward transaction or the compensating transaction must be idempotent. However in the example of email, neither seems to be the case. Obviously sending out the email is not idempotent, nor would I want to flood the customer's inbox with hundreds of "disregard the last email" messages if the compensating action needs to be retried.
Only send one email.
What's stopping you from sending a second email? That sort of thing happens all the time with e-commerce sites. You get one email with your order confirmation and another later when the order has shipped. You may also receive an email saying your order was cancelled or the shipment was delayed. All of those are valid compensations for the original email(s).
An LLT is a saga if it can be written as a sequence of transactions that can be interleaved *with other transactions*. What the presenter mentioned at 10:11 (the one gotcha that sub-transactions cannot depend on one another .. T2 cannot take input from T1) is not correct!
she keeps mentioning about the paper. Do people read many published papers? How do I know which kickass concept I have to use? It must be published somewhere in a paper?
they are usually the source of some of the trends for more complex patterns. It is good after you read a blog or presentation to see in more details and get your own conclusion for your domain.
Beautiful. Then, are there translations for Chinese? Thank you.
Ohohoho! Perfect explanation. Now I can do my homework )) I'll borrow a couple of your slides if you don't mind of course. Thx!
I wonder if this pattern (transaction idempotentcy) can be applied in financial world? Probably it will be more complex solution - if you for example do fund transfer, how would your system retry if transaction failed...Also how compensation will work?
Hi Basilio100, Maybe then you need to add a bit of logic there and identify your transaction with an ID, e.g see if you have already applied this ID rollback... What do you think?
@@davidc24994 don't know. I did few POC projects, used correlation Id to mark transactions... All is not so easy...
This didn't click last time I watched this, this time it's like I already understood the whole thing. When did I actually learn it lol.
Looks like a great fan base here for her... God Save them!
nice explanation and slides. i'm wondering where is the saga state stored if it's not in SEC?
My english is terrible but she is great even for me all was understandably
Totally stupid question - how do you achieve idempotency when you are making a totally new car/hotel/flight booking? Wouldn't that be a POST request? a new entry in db of the remote service? and POST is not idempotent.
.. and i got my answer :P - medium.com/@saurav200892/how-to-achieve-idempotency-in-post-method-d88d7b08fcdd
Some kind of request_id for request deduplicating. But how to generate it reliable in a distributed manner even in the case of Coordinator crash is not an easy task :))
25:43 Doesn't it make sense t hat it's always the best game they've ever had? Doesn't seem that people are likely to be as upset or call in if you got their stats wrong on a game that they played terribly.
21:38 What if the compensating request fail😂
This is very important actually. You need to capture that compensating transaction failed and mark it for manual intervention to fix it manually. Also, you can have a retry mechanism in place that could help but not always, manual intervention might still be needed. Sometimes even manual intervention could be hard to do as some other events are already applied some changes to that resource so it can become quite challenging to get back to a consistent state in this case.
came from redux-saga docs ... didn't understand
Yup it was like watching how to build a skyscraper when you need to build a doghouse.
same! :(
As far as I can tell, the Sagas discussed here and Redux Sagas are two very different concepts.
cantik
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Good explanation, but why you talk way too fast as if you on the run ?
Gogo Ubari I am sure they didn’t give her an unlimited amount of time to make the presentation, maybe she has a lot to say?
Most people, including professional developers, don't have public speaking as their day job. She was perfectly understandable the way she presented it.
nothing new in the distributed transaction world. same old concepts execute/undo with an appealing name
Great content but TERRIBLE Speaker: Comme on, we are ment to work on a global scale. So do not speak the way you would speak for a bunch of local American-Friends in a TacoBell . Get dressed, sneeze and moderate your talking speed, please!
comments about attire aside, if you don't like the video's speed, you can slow it down by clicking 'settings' in the bottom right, and selecting 'speed'.
there just isn't a speed that's appropriate for everyone--I'm a native speaker, so I prefer quicker speakers. I think the best option is for the speaker to speak however fast they want, and then let the users decide at what speed they wish to listen.
seriously, a tech guy commenting about the attire? what about male presenters on shorts and t-shirts? I dont find the dress too bad. and the presentation is pretty good too. like +lennahc said you can slow the speed and turn on the caption.
René Baron as a non English native speaker I felt uncomfortable with her speed, but it is still a good talk by the way
Ps. It is not possible slow down video speed on mobile devices :(
Well I do agree that the speaker talks fast, but it didn't bother me much and I'm not a native speaker. She speaks clearly and loud enough and honestly I prefer this to those 2-hour long talks where the speaker is more concerned about his developer tales and jokes than the subject of the talk.