12 ms·
Google and Microsoft Cheat on Slow-Start. Should You?
- AndrewDucker 15y agoIt doesn't seem that unreasonable to make a starting point of the median number of packets that Google's customers can cope with at once, and then fail down the way for those that have problems.
- kennu 15y agoIt's kind of interesting that Google breaks TCP/IP protocol rules (RFC 3390) and their home page has never been valid HTML either.
- seabee 15y agoYou'd probably be inclined to cheat if your business had the most-viewed web page in the (Western?) world.
- SquareWheel 15y agoAbsolutely. Think of the bandwidth cost of a single character. Google.com isn't made to be pretty, nor should it be.
- tfb 15y agoI'm not sure I would call it cheating. When I think of cheating, I think of a restricted action that gives an unfair advantage over competitors, of which is incredibly difficult for competitors to duplicate. But implementing the same hack, in this case, is easy, fairly common, and it isn't stepping outside of any real boundaries so it's not like the playing field is uneven. It also works and works well to provide users (customers) with a better experience.
- bzbarsky 15y agoThe problem is that if everyone implements a very large initial congestion window that just causes more network load on networks that can't handle that amount of data all at once. So it's not "cheating" in terms of your competitors, but it's "cheating" in the sense that either you're basically jumping the queue for your TCP flows or everyone else does the same thing and then things are back to square one, if networks can't deal with it. An argument that networks now can deal with much larger congestion windows can be made, and Google is making it in the IETF, of course.
- zalew 15y agofirst you learn how to use the rules, then you learn how to break them.
- sanxiyn 15y agoI thought this is actually in the process of being standardized? http://tools.ietf.org/html/draft-ietf-tcpm-initcwnd-02 http://tools.ietf.org/html/draft-ietf-tcpm-initcwnd-02
- ck2 15y agoThis seems like deja-vu, I swear this was on HN before. (yeah probably without the m=1 on the url) Anyway, super easy to try on linux servers. First double check your existing setting sysctl -a | grep tcp_slow_start_after_idle then sysctl -w net.ipv4.tcp_slow_start_after_idle=0 if you want to enhance to IW10 then first check the last line of ip route show should be something like default via 1.2.3.4 dev eth0 then copy it to the middle of this ip route change default via 1.2.3.4 dev eth0 initcwnd 10 if you are using a VERY current linux kernel, you can also add initrwnd like so: ip route change default via 1.2.3.4 dev eth0 initcwnd 10 initrwnd 10 Note the ip route change is not permanent unless you add it to something like /etc/rc.local You should be able to see the change before/after in wireshark if you look very very carefully at the milliseconds before the first real ack.
- RollAHardSix 15y agoThis has been on HN before. I read the article and comments as well as used the information at work. If I had time I would go dig it out but unfortunately I'm leaving for a midterm. Maybe someone else can find it; I think it had a good discussion with it.
- devgutt 15y agoYes, original post on HN 455 days ago http://news.ycombinator.com/item?id=1942442 http://news.ycombinator.com/item?id=1942442 Op Follow up http://blog.benstrong.com/2010/11/slow-start-follow-up.html http://blog.benstrong.com/2010/11/slow-start-follow-up.html
- finnw 15y agoI didn't realise it had been on HN already. I just saw it because Sam Saffron tweeted it. I guess I should search more thorougly (I just searched for "cheat" and checked the first page.)
- SkyMarshal 15y agoDon't sweat it, I didn't see it the first time and it's a good read, glad it was reposted. I'm sure I'm not the only one. Also, HN search for previous submissions is hit or miss. A more reliable way is to search ddg or google for 'site:news.ycombinator.com [url you want to submit]'.
- deleted 15y ago[deleted]
- ChrisLTD 15y agoSlightly off topic: the Blogspot mobile theme is killing me with their swipe left and right gestures to navigate posts. When I'm scrolling down the page on my iPhone, I accidentally activate it constantly.
- joblessjunkie 15y agoThis happened to me twice while trying to read this post. It's frustrating how often a website will provide a client-specific rendering which is much worse than the default. (I'm looking at you, Wordpress).
- joedev 15y agoBen fails to mention that the equation he proposed is "violated" is expressly "optional" and in fact the standard allows that "a TCP MAY start with a larger initial window".
- joedev 15y agoMaybe I'm not reading rfc3390 right? This: "This increased initial window is optional: a TCP MAY start with a larger initial window." And specifically this: "MAY start with a larger initial window". "larger" than what? a.) larger than that proposed? or b.) larger than was standard before this proposal?
- Natsu 15y agoFrom the article: > Being non-standards-compliant in a way that privileges their flows relative to others seems more than a little hypocritical from a company that's making such a fuss about network neutrality. That's completely off the mark. NN was a reaction to the plan by ISPs to throttle large sites (e.g. YouTube) that their own customers were requesting unless they were paid protection money. It later became a political thing, with people mostly deciding to support (or oppose) it based on party lines. It has nothing to do with tuning one's network, in spite of rhetoric to the contrary. It was just an attempt to stop rent-seeking by greedy ISPs that has morphed politically after attracting lobbyist attention.
- deleted 15y ago[deleted]
- nn2 15y agothe microsoft behavior of disabling SS completely seems downright immoral to me. Who cares if the internet melts as long as they can deliver their home page a few ms faster. And it's not even a very interesting homepage