Reading this article is completely safe even if you already understand idempotency.
I want to meet the article that isn’t safe to read even if you’re familiar with its content.
Idempotency
21–30 of 69 posts
Re: Idempotency
#22Idempotency is one mathematical concept that's pretty useful for software engineers to understand. Heck, might be more useful than BigO. - Useful to know when you work with APIs (as the article outlines). - Very useful when working with background jobs. You're not gonna have a good time if those aren't idempotent. - Good to know for interviews. I was asked to explain idempotency a handful of times, weird as that is.
I've asked it a few times. Not knowing the specific word is fine -- but I expect devs touching http requests at all to understand the concept.
Re: Idempotency
#23pet peeve: idempotency is badly named. idempotent literally translated is ‘same power.’ two or more things having the same power doesn’t necessarily mean they produce same, single result. if that were the case we wouldn’t need the special handling for idempotent instructions/commands/actions to ensure duplicates are not created.
I’m not totally sure, but in math “idempotent” elements are those for which x^2 = x. And so in software engineering it refers to operations for which doing them twice has the same effect as doing them once. Maybe this is what is meant by “same power”?
i could agree with you. my pet peeve is that the name of the phenomenon where repeated executions result in same result (where same even includes unique identifier) shouldn't be idempotency. especially in computing where, in my experience, any attempt to implement it involves some logic which checks to see if we've already observed the desired effect of the action.
Re: Idempotency
#24> Let's say we have a food ordering application, and to keep our application simple, let's say we have two basic services, Shipping and Order. When one of our customers places an order, first the order is created, and then shipping instructions are created. If all transactions are successful, it sends a notification to the client. Even in this simple scenario, many failures can occur.
In a real-world scenario, this is what seems to happen to Uber Eats in India back in 2019 when everyone can gets free food because of a bug in Uber's backend.
Re: Idempotency
#25One of the things I think I did right in my career is working on payment and billing systems early on. It does teach you how to build at least semi-reliable software because people tend to get really mad when you screw with their money. It also is a good introduction to regulation and compliance. Idempotency was is one of the concepts you get taught on day one in that field (as kind of demonstrated by that being the…
Interestingly, I didn’t have to be taught about idempotency early on in my career; I’m pretty sure I didn’t even know what that word meant. I’m a naturally curious person and I was always curious about the failure cases for the software I worked on—e.g., “What happens if this request is successful but times out before returning a response to the client?” I honestly assumed every programmer asked these types of questi…
The only reason I knew about idempotency is because growing up I was a little shit and I learned that you could break a LOT of electronics by getting it to do a second thing midway before finishing doing the first thing.
If it had a screen and buttons, I would try to break it.
So I started striving for highly reliable systems not because there are professional bad actors out there or spammers or to achieve high performance… but because there’s another little shit out there.
Re: Idempotency
#26Re: Idempotency
#27Re: Idempotency
#28Fancy word for an obvious concept.
Re: Idempotency
#29Re: Idempotency
#30Come here to learn more details and maybe find answers to my questions. Unfortunately, the article is very modest explaining how to work with idempotency. Missing key answers like what about two requests in flight, how to store and query requests status reliably. The article mention requests should be ACID, but the diagram has caching storage. Would redis/dynamodb work here?
You might prefer my attempt at a similar explanation:
https://github.com/stickfigure/blog/wiki/How-to-%28and-how-n...