"This Raft library is stable and feature complete. As of 2016, it is the most widely used Raft library in production, serving tens of thousands clusters each day. It powers distributed systems such as etcd, Kubernetes, Docker Swarm, Cloud Foundry Diego, CockroachDB, TiDB, Project Calico, Flannel, Hyperledger and more."
etcd has had numerous liveness and safety bugs, with one happening as recently as December of 2025. Would you consider that a correct implementation?
You may be interested in knowing that the largest managed Kubernetes service in the world (AWS EKS) ripped out etcd for in favor of their homegrown consensus service for large scale EKS clusters: https://aws.amazon.com/blogs/containers/under-the-hood-amazo...
etcd is some of the most amateur code I've ever seen, despite being one of the oldest and presumably most mature "infrastructure" projects written in Go.
goBGP is arguably even worse.
I don't have a third place in mind that's even worth mentioning relative to these two.
No they won't. They are generally faster in throughput than any non-gc application that isn't heavily hand optimized. Their problems are higher memory usage and unpredictable latency, not speed.
Just look at the code. Anywhere you like. There's nothing I can say that will be a substitute for seeing it yourself.
I've had to use it as a library sometimes, and it's also really poorly designed as a library. There's no consistent principle for what is exported and what remains internal, so almost anything non-trivial you do may require you to copy-paste parts of the library code because something happened to not be exported. So you must think, okay sure, but in return for that you get a minimal and stable API. Nope! It also has some of the most API churn of any Go module, already up to /v4 and that's only counting the semver-major breakage they bothered to acknowledge, not the many semver papercuts along the way.
Sorry to pile on, but yeah, I wanted to use etcd during 2021 and 2022, around v3.5, but etcd had serious issues including silent data corruption. If you are curious, ask gemini flash "there were a number of etcd releases years ago where it seems a new wave of developers came in and started breaking everything"
I'd like to know what you base your statement on that the Raft implementations in etcd or CockroachDB are incorrect. Your original paper does not mention those implementations, so where does that claim come from?
Having run a fleet of 100s of etcd clusters for 10000s of rps, and the fact that upstream runs tests similar to antithesis and recently partnered with antithesis [0], and jepsen has tested it long ago as well [1]. Etcd's raft algorithm is fine. Someone even did a TLA+ proof on it in the last couple years[2]. Yes there was a correctness issue a few years ago but otherwise the person you're replying to doesn't know what they're talking about. Also those bugs have nothing to do with the raft implementation, but instead the state machine implemented on top.
"there was a correction issue" is downplaying it. Etcd is truly the worst example of Raft.
Etcd corruption and loss of quorum is extremely common in practice and the GitHub issues sit for years. The design is simple, the performance is modest, yet it still has still never been reliable, despite being marketed as so. I can't speak to whether this is specifically due to their Raft implementation, but I'd argue the entire codebase is over-engineered and questionable.
Their lock, leader election, sessions, and leases are all awful and I'd never recommend anyone to use those. But as a strongly consistent kv store and if you need the watch mechanics, its useful. It has its place and that's mostly being used by kubernetes.
The raft algorithm works and if you implemented a less complex state machine (like using a simpler kv store that doesn't need global event ordering via revisions and watches) it would work. That's what antithesis said they did to test the raft algorithms in the other article linked
doesnt raft have a problem that it assumes no hysteresis? and that in general you can construct a latency graph that deterministically causes a permanent lock in the leadership election phase?
I'm not sure I fully understand your question, but the heartbeat time outs and leader election time outs are static. And yeah if you make votes and heartbeats time out in a way that nobody can be elected, then raft can't make progress.
I've never had this be a problem in reality but AWS has a pretty good backbone. Maybe if you were running it over a pretty unreliable network this would be an issue?
Surely the King is doing it, so that must be the correct way. Look, the King even wears clothes and is totally not naked at all.
That the world runs on Kubernetes is no qualitative statement about the correctness of its Raft implementation. You can say that it's clearly good enough to not matter most of the time, but that is a different statement.
No matter who you look at, they're just cooking with gas like you do, and they can make mistakes in just the same way.
Now; I'm only attacking your argument. I do neither know nor particularly care about the correctness of that implementation itself. There's been better refutations of the claim you replied to in other answers anyway.
I have a bunch of volumes that I'd like to get automatically attached and mounted to nodes on which their respective workload runs (which are automatically scheduled) who automatically fetch and mount their config files and secrets from a HA DB on demand. I also need some internal loadbalancing and integrations with something like certbot for all of my web workloads. Id also like to make sure that I get metrics and logs from every workload in some form.
Thats basically it for starters, what non-technical solution do you propose?
So you propose to just let Ops personnel handle attaching volumes and renewing certificates, that these arent technical problems but just one of team structure?
Please, do describe your solution for the concerns above. So far Ive only seen equivalents of Greenspun's tenth rule
Having maintained multiple etcd clusters for self-managed kubernetes the last few years I disagree with the "problematic" characterization.
Sure it may not be the best fit in a scenario where you want a cluster spanned over the entire globe (thats why GKE uses paxos-based Spanner instead of it) , but even spanned across an entire continent (in europe via glass fiber) it works quite well for me. Its one of the least problematic parts of the stack.
I don't care for Go myself (especially its concurrency model, which is a total dinosaur in a world where we have structured concurrency) so I'm not saying this to support my favourite language, but:
Are you saying that this implementation is wrong?
"This Raft library is stable and feature complete. As of 2016, it is the most widely used Raft library in production, serving tens of thousands clusters each day. It powers distributed systems such as etcd, Kubernetes, Docker Swarm, Cloud Foundry Diego, CockroachDB, TiDB, Project Calico, Flannel, Hyperledger and more."
One of the most popular distributed DB is Cockroach which is written in go and also uses Raft: https://github.com/cockroachdb/cockroach/tree/master/pkg/raf...