On 4/18/06, Leszek Matok <Lam@xxxxxx> wrote: > Dnia 17-04-2006, pon o godzinie 21:45 -0400, seth vidal napisał(a): > > It just means we have to make an additional temp file and compare it > > every time. It costs time for the generic case where the files have > > changed and are newer. That being the most common case. > The most common case? Maybe if you use one server only. I use FC5 > default config which uses a ton of mirrors. I am downloading "new" > version of the same repo's "primary.xml.gz" every half an hour (with > many versions spread among the mirrors) and other users are doing the > same thing. Yes, I know I can use "yum -C", but I really want to have > the newer data downloaded when I use yum list/yum install (which I do > pretty often), why can't I? > > When I think about the cost I see one assembly jlt/jgt (how many CPU > cycles? ;)) to check if a timestamp is less (file is older) and issuing > a "move file" operation from (let's say) repomd.xml.tmp to repomd.xml, > which 1. is handled by kernel and kept in cache for a while, so no > slowup for yum and 2. "download xml.tmp;remove xml;move xml.tmp to xml" > instead of "remove xml;download xml" doesn't cost much more instructions > as I see it. > > Oh, and last night I updated updates' cache with the updates at 1:00, > but wanted to download it when I sleep (86 MiB of updates after manually > taking pilot-link from updates-testing - this took over 2,5 hours on my > link), so (stupid me) instead of "yum -C" I did a "yum update" an hour > later. > > Turned out there were three repo versions on the mirrors (with > primary.xml.gz having 122, 130 and 161 "k"B). I ended up doing "yum > clean all; yum update" (with only one repo enabled) for 10 straight > minutes just to see the data I already had over an hour earlier. It also > downloaded megabytes of useless data from the mirrors - to hell with my > link, but it costs the mirrors' bandwidth. All this IS a cost, but > simple "if timestamp2 > timestamp1" isn't. > > I'm really not moaning, I can live with that until I get my hands on the > new apt, but I think about the others - why do they have to live with > it? :) > > Lam > Seems like Squid could help you out a bit. -- As a boy I jumped through Windows, as a man I play with Penguins. -- fedora-devel-list mailing list fedora-devel-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/fedora-devel-list
