I don't sense any hostility here, just healthy skepticism. At the risk of sounding condescending, building something for a class assignment is very different from building something that you'd feel comfortable rolling out in production. Hell, one of the commenters upthread worked on the implementation of raft in Apache Kudu. To be perfectly frank, I would take their word on something before that of someone talking about their homework assignment. It's an incredibly useful learning tool, but it takes a lot more work to make it robust.
I really hope you read this gently. (As the HN guidelines say, "Please respond to the strongest plausible interpretation of what someone says, not a weaker one that's easier to criticize. Assume good faith.") I'm not trying to talk down to you or treat you with hostility (and I know that it's really hard to convey that via text). I would just ask that when someone who has professional, real-world experience in something says it is difficult and time-consuming to do it right, you'd avoid assuming they just don't know what they're doing, and that perhaps there are aspects that you haven't considered.
And hey, maybe you or some of the other commenters are just ridiculously smart and focused and can write it in a weekend. But if that's the case, it's pretty uncharitable to push a narrative that it's trivial. Not saying that's what's happening here, but that could be how it's coming off.
I'm not the parent. But I hope you can see how downvotes to oblivion and a bunch of people saying "no you didn't," is hostile.
This is a proportionate response to an undergraduate trying to sell you his new RDBMS. But most students really did write a b-tree. Academic programming elides the supporting infrastructure that bridges the gap between algorithm and software system. Textbooks aren't generally leaving out 100 pages of extra steps required for the list to actually be sorted or the path to actually be shortest. And so a student is not exactly out of line for thinking that the Raft he was taught is actually consistent in the presence of failure. I'll defer to the community's wisdom that he's wrong! But he's still not out of line.
If anything, I'm worried about these classes instilling false confidence. People who think they know these algorithms may go implement them professionally, and not have anyone around to tell them the full story. Cryptography education is careful to put asterisks around "Textbook RSA." Distributed systems education should probably be doing the same.
I really don't think my initial comment was that hostile, but I can see why it could be read that way. I appreciate what you're trying to say here, and should probably work on framing things positively to avoid this kind of contention.
Part of why the Raft paper is so excellent is because is does leave you feeling like you could explain/implement the algorithm. I don't want to discourage people from being excited about these ideas, because I am too.
That being said, I am generally frustrated by the lack of humility that many software engineers exhibit. "Easy" is a trigger word for me, and I really think is something that should be expunged from most of our vocabulary when referencing software.
Right, my point was just that there's no such thing as a "mostly works" consensus algorithm. By definition these algorithms are intended for systems that can't tolerate failure.
If you feel confident you've built a complex algorithm like this correctly on the first try you probably haven't. Hubris and distributed systems just don't mix.
Verifying correctness to back up our empirical claims is often the hardest and most overlooked part of software engineering.
well in the case of raft for Apache Kudu the commenter says that most of the complexity came from the interaction between the database-log semantics and the raft-log semantics.
this is almost independent with how hard is to build a (good) pure implementation of raft that offers a simpler API
I really hope you read this gently. (As the HN guidelines say, "Please respond to the strongest plausible interpretation of what someone says, not a weaker one that's easier to criticize. Assume good faith.") I'm not trying to talk down to you or treat you with hostility (and I know that it's really hard to convey that via text). I would just ask that when someone who has professional, real-world experience in something says it is difficult and time-consuming to do it right, you'd avoid assuming they just don't know what they're doing, and that perhaps there are aspects that you haven't considered.
And hey, maybe you or some of the other commenters are just ridiculously smart and focused and can write it in a weekend. But if that's the case, it's pretty uncharitable to push a narrative that it's trivial. Not saying that's what's happening here, but that could be how it's coming off.