IBM owns a very high-performance XSLT engine they could probably open source or license to the browser makers. IF anyone from IBM is here (?), may want to consider it..
Readit Newsstmw commented on "Remove mentions of XSLT from the html spec" github.com/whatwg/html/pu... · Posted by u/troupo
Raft played a huge role in improving how consensus is taught, compared to Paxos.
It’s hinted at in the introduction to the Raft paper, that Raft is "most notably" similar to Viewstamped Replication from Brian Oki, Barbara Liskov and James Cowling at MIT. Reason being that Raft’s primary goal was not so much to reinvent or contribute consensus, so much as to repackage consensus to be "more understandable than Paxos". Nevertheless, it’s not widely known, and probably could be emphasized a bit more, that the protocol is otherwise pretty much ‘88 Oki VSR (same essential protocol, different terms), itself predating Paxos a year.
For example, if you compare '14 Raft (Stanford) with '12 VSR (MIT’s revision to their ‘88 original), the resemblance is striking:
2012: http://pmg.csail.mit.edu/papers/vr-revisited.pdf [1]
2014: https://raft.github.io/raft.pdf
Presentation aside, the only major difference is that Raft’s view change (called leader election in the Raft paper) preserves the flavor of Oki’s ‘88 Viewstamped Replication view change, electing the candidate with the longest log, and missing out on the improved round-robin view change from MIT in ‘12, that brings better stability and availability, with lower latency, and no dueling leaders.
Raft has had a tremendous impact, compared to Paxos, in helping engineers to understand consensus. But once the training wheels are there, it’s important that we also understand and preserve the history of consensus, the people who pioneered these protocols.
[1] It's an accident of history that '12 VSR wasn't promoted as much as Raft would be, two years later. Otherwise, '12 VSR from James Cowling is arguably just as understandable, if not more. For example, because of the improved view change, the paper can begin immediately with normal replication. And there's no discussion, for example, of the need for randomized timeouts, it's elegantly designed away.
Re: "It's an accident of history that '12 VSR wasn't promoted as much as Raft would be, two years later. " - more accurate to say MIT vs Stanford difference.
Worth noting, not quite "everyone" does this. Cassandra uses "leaderless" (single decree) paxos, which has some advantages and some disadvantages (for instance, 1RT WAN reads from any region).
I agree with you that Paxos is simpler than Raft. The problem with Paxos IMO is that Lamport's original paper is impenetrable; lots of later writing is easier to understand, including those that describe more complex protocols. The intuitions are actually pretty straightforward, and transfer to all of the extensions to Paxos (which are not as straightforwardly compatible with Raft).
Raft may have helped more people get comfortable with distributed consensus, and sped its adoption, but being a sort of dangling branch of the tech tree I wonder if this may have stalled progress beyond it.
Interesting way to think about, I am not sure I quite agree, but good points and surrounding discussion for sure..
Both the Raft algorithm and its explanation are excellent, including this little animated demo that Diego Ongaro (who is also a great guy) made to help explain his invention. While Paxos was first and still popular, I am not sure I would count against any senior engineer unable to explain it to others. With Raft, one ought to be able to do it.
Great to see this on HN.
Website link is broken?
stmw commented on A fast, growable array with stable pointers in C danielchasehooper.com/pos... · Posted by u/ibobev
This is really clever but better to call this a list rather than an array; functions which expect array semantics will simply not work, and there's no way to transparently pass slices of this data structure around.
In the past I've abused virtual memory systems to block off a bunch of pages after my array. This lets you use an array data structure, have guard pages to prevent out of bounds access, and to have stable pointers in the data structure.
Same re: virtual memory systems (using guard pages), that is an old idea that works well but it did once produce a really unpleasant bug in production... But that was an unfortunate implementation mishap.
stmw commented on The Rickover Corpus: A digital archive of Admiral Rickover's speeches and memos rickovercorpus.org/... · Posted by u/stmw
From the website:
This project was compiled and digitized by Charles Yang under the Center for Industrial Strategy, with assistance from Jacks Flenniken.
Some credit also given to the US Naval Academy archivists (usna.edu), and whoever preserved his files to begin with.
XSLT used as a "stylesheet" in browsers isn't dynamic, so it's like browsing static HTML pages, but expanding of on-the-wire data representation into repetitive HTML is done with XSLT's rules instead of just gzip/brotli (and it doesn't make much difference, because regular compression is really good at compressing the same things that XSLT is good at generating).
For XHTML the effect is almost identical to preprocessing the data server-side, except minor quibbles about whose CPU time is spent on it, how many bytes can be saved.
The only remaining use-case for XSLT is stopping browsers from displaying RSS like garbage, but that's using one browser feature to fix another browser regression. It'd be easier and more helpful to bring back integrated RSS readers, instead giving you very sophisticated technology for apologising how useless the RSS URL is.