On Thu, 2015-02-26 at 04:23 -0500, Kamil Paral wrote: > > Hey folks! Anyone paying attention to the Project Coconut box logs > > might've noticed it failed when it tried to run against Alpha TC5. > > The problem is to do with the download URLs. I wrote fedfind to > > always use https://download.fedoraproject.org/URLs for mirror HTTP > > downloads, but this turns out not to work great for TCs/RCs > > because of mirror lag, people (and Coconut) want the images > > immediately but mirrors don't pick them up for a few hours after > > the TC/RC is cut. > > I think the problem is different. (Almost) nobody mirrors TCs/RCs. > There are about 3 mirrors in the whole world which follow stage/ > directory: > http://mirrors.fedoraproject.org/mirrorlist?path=/pub/alt/stage > > Also, you would need to ask infrastructure folks, but I don't think > download.fp.o can be used for this. I think it redirects to a random > close mirror without actually checking the path you are requesting. > If you wanted to be sure that the file is present, you would need to > make calls like these in advance: > http://mirrors.fedoraproject.org/mirrorlist?path=/ > pub/alt/stage/22_Alpha_TC4/Workstation/i386/iso/Fedora-Workstation- > netinst-i386-22_Alpha_TC4.iso > > Those calls are quite slow and probably expensive. And they change > in time, you can't use them immediately after TC/RC is published. > So, for anything under stage/, I believe using dl.fp.o is the best
Well, in the end it's academic, but download.fp.o is a *bit* more sophisticated. download.fp.o does not redirect just to any 'fedora mirror', it does make an attempt to redirect to a 'valid' mirror, but the check is limited. What it does is make sure it redirects to a mirror which claims to carry the relevant bundle. So for a /stage/ URL it will never redirect you to a mirror that simply doesn't mirror stage at all. However, apparently it can't do an actual path check for the exact location you request, so it can't quite manage to be as accurate as mirrormanager is when you make a 'path' request. So the problem is, as I said, the mirror lag: the mirrors that *do* carry /stage/ don't mirror it instantly. Some of them don't seem to mirror it even hourly, or anything - some of them still didn't have TC5 7 or 8 hours after it hit dl.fp.o. So download.fp.o gives you a URL that *ought* to be OK, but in practice, the mirror likely hasn't caught up yet. So in the end we come to the same conclusion, for things in stage/, using download.fp.o just isn't a good idea, and as I said, I've made it so fedfind doesn't use download.fp.o for TC/RC images...only thing is I had to do it in a bit of a hacky way because of how I designed fedfind, doing it in a cleaner way isn't *entirely* straightforward. I'll have to think of the best way to go about it for a permanent fix. The hack should *work* fine for the foreseeable future, though, it's just theoretically stupid code (it's really in the wrong place and messes up the design). -- Adam Williamson Fedora QA Community Monkey IRC: adamw | Twitter: AdamW_Fedora | XMPP: adamw AT happyassassin . net http://www.happyassassin.net _______________________________________________ qa-devel mailing list [email protected] https://admin.fedoraproject.org/mailman/listinfo/qa-devel
