u/jrvin r/compsci • Recommends
A great video explaining Raft, the recently published consensus algorithm that aims to be more understandable than Paxos
0:00 / 0:00
#raft#paxos#distributedconsensus
Raft lecture (Raft user study)
Diego Ongaro
2.8K subscribers • 2 videos on Hallway
- Recommended by 5 people: 4 on Hacker News and 1 in engineering communities.
- A classic. People kept recommending it from 2013 to 2025.
- Presented by John Ousterhout
Intermediate. Assumes working knowledge.
86K views13 years ago5 recommendations
Distributed systemsConsensus: Raft and PaxosReplication and consistencyFault tolerance and failure
John Ousterhout explains the Raft consensus algorithm, covering leader election, log replication, and safety properties.
This lecture is part of the Raft User Study, an experiment to compare how students learn the Raft and Paxos consensus algorithms. It's a useful introduction for anyone learning Raft. Slides and voice-over by John Ousterhout. Slides, more info, etc: raft.github.io/ and ramcloud.stanford.edu/~ongaro/userstudy/ Corresponding Paxos video: youtu.be/JEpsBg0AO6oWhy it's here
5 people recommend thisWhat people say. Highly recommended as the definitive and most understandable video introduction to the Raft consensus protocol.
krat0sprakharon Hacker News • Recommends
On “The Raft Consensus Algorithm”
…ucted an experimental study using CS students at two universities. We recorded a video lecture of Raft and another of Paxos, and created corresponding quizzes. This page makes our materials available for anyone interested. We think these are valuable resources for anyone learning consensus (whether Raft or Paxos or both). 0 - link Raft Video - link to this video Paxos Video - link…
tomjohnson3on Hacker News • Recommends
On “ZooKeeper vs. Doozer vs. Etcd”
…that said, raft has a lot of interesting applications, and, in my opinion, is definitely more understandable than the many versions of paxos. (implementing zab yourself, at this point, would be a futile exercise.) i found the videos from the raft user study to be very well done (and easier to understand than even their paper): raft: link paxos: link to this video ...however, i think they did paxos a disadvantage by not just focusing on multi-paxos (which is probably the most common implementation). but, it's certainly fair to say that info about paxos is spread out far and wide...with perhaps too many knobs to turn and implementation-related details to fill in yourself. as a side note: i've just sta…
pkjon Hacker News • Recommends
On “The Writings of Leslie Lamport”
A really good intro to Raft --> link to this video Very useful if you are into distributed systems and would like to see a practical implementation with clear examples.
sathish316on Hacker News • Recommends
On “The Raft Consensus Algorithm (2015)”
This YouTube video by the Raft creators (linked at the bottom of the page) gives a solid explanation of Raft internals - link to this video
tomjohnson3on Hacker News • Mentions
On “ZooKeeper vs. Doozer vs. Etcd”
i don't think this is the case. here is a link to a video by one of the authors about log repair during leader election: link to this video log entries on a follower may get rolled back - and thrown out - since they were not accepted on a majority of followers.
deathanatoson Hacker News • Mentions
On “Raft: Understandable Distributed Consensus”
…l way of resolving a conflict in election This is mostly true. The PDF slides I link to below recommend that the election timeout be much greater than the broadcast time, the idea being that things should work out in the long run. Highly recommend the PDF slides here, as they explain it better than I can: link — there's also a YouTube talk here: link to this video > Considering all that, this protocol doesn't seem very interesting (from a use-case point of view). I'd love to hear of alternatives.…
nieksandon Hacker News • Mentions
On “Ask HN: Final year project in CS”
Consider doing some language processing using the excellent NLTK library: link It wasn't on the lists of "wants", but implementing the Raft consensus protocol could be neat too. It was designed to be understandable and implementable. The video is here: link to this video . The research paper is here: link
throwawaybbq1on Hacker News • Mentions
On ““They introduce kernel bugs on purpose””
…etter than that but again, may not generalize to the real world. One of the most impressive ways I have seen this being done by grad students was a user study by John Ousterhout and others on Paxos vs. Raft. IIRC, they wanted to claim that Raft was more understandable or led to fewer bugs. Their study design was excellent. See here for an example: link to this video ]…
ignoramouson Hacker News • Mentions
On “Paxos vs. Raft: Have we reached consensus on distributed consensus?”
Raft is very similar to Multi-Paxos. These Raft and Paxos user studies comparing the "understandability" of the two protocols might be helpful: link (Paxos), link to this video (Raft). See also, comparison of various "Paxos" implementations: link