On Fri, 2010-03-12 at 14:21 +0000, Fred Williams wrote: > On 12 March 2010 14:08, Patrick O'Callaghan <pocallaghan@xxxxxxxxx> > wrote: > The yum fastestmirror plugin (yum-plugin-fastestmirror) claims > to > evaluate the speed of a bunch of repo mirrors and use the > fastest one > relative to the user's location. > > However AFAIK what it *actually* does is make a test > connection to the > to the candidate mirrors and order them according to response > time, > which in many cases is dominated by network latency, which can > distort > the results. For well-connected user machines in first-world > countries > it probably doesn't matter much, and may have the beneficial > effect of > spreading the load over a wider range of mirrors, but for > those of us in > a less privileged position it can matter a lot. Ironically, > these are > the cases where such an optimization could do the most good. > > A case in point: I live in Venezuela and on several recent > occasions yum > decided that my closest repo was in Puerto Rico, which as the > packet > flies is probably true. However the b/w I got as a result was > around 2 > or 3kbps. > > I tried renewing the mirror cache. No difference (ping times > tend not to > vary much). > > I then manually edited the /var/cache/yum/timedhosts.txt file > to bias > the results against the mirror yum was choosing (I made it > worst rather > than best). Oddly, it again made no difference! It seems > there's a > cunning hidden cache of these results that I don't know about. > Finally I > disabled the plugin completely and got decent b/w without it. > > Perhaps we should be considering some kind of BitTorrent > version of the > repos in which the mirrors are seeds and the users are > leeches, though I > realize that this is harder than it looks, particularly when > taking into > account the synching of the mirrors themselves. > > poc > > -- > users mailing list > users@xxxxxxxxxxxxxxxxxxxxxxx > To unsubscribe or change subscription options: > https://admin.fedoraproject.org/mailman/listinfo/users > Guidelines: > http://fedoraproject.org/wiki/Mailing_list_guidelines > > Perhaps not so difficult - though I've never used them myself, I > recall that in the Debian, if not Ubuntu (Sometimes hard to tell) > repositories are some packages that allow for bittorrent fetching of > deb packages - perhaps if they're still relevent and working, they > could be used as a base to create a means of implementing the same, > maybe as a plugin for Yum or similar. > Theoretically, I think the only main differences are the download > protocol. HTTP/FTP or BitTorrent. Once downloaded the package can > still be used in the same way, there's no difference there. > The main downside I see to it is that those users on an ISP which > throttles BitTorrent will suffer, and have to go back to standard > downloads, but if both are provided, then no issue. Or at least very > little. > Just my 2p. Or 2c, depending on your currency. Interesting. I'll see what I can can find on BT use in the Debian/Ubuntu world. poc -- users mailing list users@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe or change subscription options: https://admin.fedoraproject.org/mailman/listinfo/users Guidelines: http://fedoraproject.org/wiki/Mailing_list_guidelines
