3 ms·

Funnily enough, there is a paper on exactly what you're referring to from Microsoft Research called "Flexible Paxos": https://arxiv.org/pdf/1608.06696.pdf http

by SEJeff 10y ago

Funnily enough, there is a paper on exactly what you're referring to from Microsoft Research called "Flexible Paxos": https://arxiv.org/pdf/1608.06696.pdf https://arxiv.org/pdf/1608.06696.pdf The gist of it is that there are realistically 2 quorums to be had: One for read/write to a cluster, and one for leader election. Assuming leader election is a relatively uncommon event (as it is in Paxos), you can require more quorum nodes for leader election while allowing less quorum nodes for quorum read/write. This means you get strong consistency with better performance. Distributed systems are one of my favorite things. I literally spent part of an evening with a beer reading a small handful of papers like this one. If you want an absolute treasure trove of similar works, visit the blog of Adrian Coyler: https://blog.acolyer.org/ https://blog.acolyer.org/ He has a good writeup on the Flexible Paxos paper as well: https://blog.acolyer.org/2016/09/27/flexible-paxos-quorum-intersection-revisited/ https://blog.acolyer.org/2016/09/27/flexible-paxos-quorum-in...

irfansharif 10y ago
yup, I've been closely following Heidi's work for some time now - non-intersecting consensus groups, still hoping someone beats me to a Go implementation so I don't have to. +1 for Adrian Coyler's blog, constantly amazed at the sheer volume and depth of his analyses.
- SEJeff 10y ago
  Ah got it. I was thinking, "Wow, this is literally someone describing the Flexible Paxos work. I wonder if they have read the paper?" Distributed systems learning ftw
rystsov 10y ago
Btw, Gryadka uses an idea of quorums with non-standard size to change a configuration of the cluster, see http://rystsov.info/2016/01/05/raft-paxos.html#details1 http://rystsov.info/2016/01/05/raft-paxos.html#details1. I came up with this idea independently of Howard when misread the Vertical Paxos paper :)
Xorlev 10y ago
> I literally spent part of an evening with a beer Just one? :) Consensus algorithms are _fascinating_! And +1 for https://blog.acolyer.org/ https://blog.acolyer.org/ , I'll often read his blog over lunch. Another great paper is https://research.google.com/archive/paxos_made_live.html https://research.google.com/archive/paxos_made_live.html which talks about what it's like to realistically run Paxos. There's a ton of corner cases, engineering realities, and optimizations to be done to make Paxos work well in practice. Another good resource is the Raft GitHub page[1] which links to the paper, has an interactive visualization, and a plethora of talks by various people. Raft is the backbone of opensource, I'd be curious to hear from any Googlers in the know whether there's deficiencies in Raft that lead to continued use of Paxos, or if it's experience (and already battle-tested code) with Paxos that leads them to continue deploying Paxos-backed systems. [1] https://raft.github.io/ https://raft.github.io/
- SEJeff 10y ago
  Great comments and links! Pretty sure Google wrote chubby before raft existed. Chubby paper: 2006 http://dl.acm.org/citation.cfm?id=1298487 http://dl.acm.org/citation.cfm?id=1298487 Raft paper: 2014 http://dl.acm.org/citation.cfm?id=2643666 http://dl.acm.org/citation.cfm?id=2643666 If you've got something battletested, there isn't a lot of value to rip it all up if it works within the given business requirements. Also they figured out how to implement Multi-Paxos, which is known for being difficult.

by SEJeff 10y ago

irfansharif 10y ago

yup, I've been closely following Heidi's work for some time now - non-intersecting consensus groups, still hoping someone beats me to a Go implementation so I don't have to. +1 for Adrian Coyler's blog, constantly amazed at the sheer volume and depth of his analyses.

SEJeff 10y ago
Ah got it. I was thinking, "Wow, this is literally someone describing the Flexible Paxos work. I wonder if they have read the paper?" Distributed systems learning ftw

rystsov 10y ago

Btw, Gryadka uses an idea of quorums with non-standard size to change a configuration of the cluster, see http://rystsov.info/2016/01/05/raft-paxos.html#details1 http://rystsov.info/2016/01/05/raft-paxos.html#details1. I came up with this idea independently of Howard when misread the Vertical Paxos paper :)

Xorlev 10y ago

> I literally spent part of an evening with a beer Just one? :) Consensus algorithms are _fascinating_! And +1 for https://blog.acolyer.org/ https://blog.acolyer.org/ , I'll often read his blog over lunch. Another great paper is https://research.google.com/archive/paxos_made_live.html https://research.google.com/archive/paxos_made_live.html which talks about what it's like to realistically run Paxos. There's a ton of corner cases, engineering realities, and optimizations to be done to make Paxos work well in practice. Another good resource is the Raft GitHub page[1] which links to the paper, has an interactive visualization, and a plethora of talks by various people. Raft is the backbone of opensource, I'd be curious to hear from any Googlers in the know whether there's deficiencies in Raft that lead to continued use of Paxos, or if it's experience (and already battle-tested code) with Paxos that leads them to continue deploying Paxos-backed systems. [1] https://raft.github.io/ https://raft.github.io/

SEJeff 10y ago
Great comments and links! Pretty sure Google wrote chubby before raft existed. Chubby paper: 2006 http://dl.acm.org/citation.cfm?id=1298487 http://dl.acm.org/citation.cfm?id=1298487 Raft paper: 2014 http://dl.acm.org/citation.cfm?id=2643666 http://dl.acm.org/citation.cfm?id=2643666 If you've got something battletested, there isn't a lot of value to rip it all up if it works within the given business requirements. Also they figured out how to implement Multi-Paxos, which is known for being difficult.