$ echo "now: $(TZ=GMT date)"; wget -S -q http://azure.archive.ubuntu.com/ubuntu/dists/vivid/Release -O /dev/null now: Fri Apr 3 14:37:31 GMT 2015 HTTP/1.1 200 OK Date: Fri, 03 Apr 2015 14:37:31 GMT Server: Apache/2.2.22 (Ubuntu) Last-Modified: Fri, 03 Apr 2015 14:28:00 GMT ETag: "34f32-512d2c15bbc00" Accept-Ranges: bytes Content-Length: 216882 Cache-Control: max-age=1228, proxy-revalidate Expires: Fri, 03 Apr 2015 14:58:00 GMT Keep-Alive: timeout=5, max=100 Connection: Keep-Alive
So the 'Expires' is most definitely in the future. This one is currently 21 minutes in the future. I didn't say that the solutions I pointed to were complete, but the fact that people are attempting to solve the problem (and doing so incorrectly) should indicate a need for a good solution. It would seem possible for apt to go through the sources.list (+sources.list.d/*) and figure out what it was going to download. It could decide based on previously stored headers or a global default "5 minutes" or a per-mirror default if it should bother. Of course it would make sense to have the ability to force. running 'apt-get update' on a system does take real time. On a cloud instance with a on-network mirror: % TIMEFORMAT='real=%3lR user=%3lU sys=%3lS' bash -c 'for i in $(seq 1 10); do printf "%-3s " $i ; time apt-get update -q >/dev/null; done' 1 real=0m3.987s user=0m3.628s sys=0m0.244s 2 real=0m4.052s user=0m3.688s sys=0m0.220s 3 real=0m3.980s user=0m3.656s sys=0m0.204s 4 real=0m4.077s user=0m3.676s sys=0m0.272s 5 real=0m4.068s user=0m3.732s sys=0m0.228s 6 real=0m4.052s user=0m3.688s sys=0m0.236s 7 real=0m4.201s user=0m3.812s sys=0m0.248s 8 real=0m4.247s user=0m3.852s sys=0m0.252s 9 real=0m4.059s user=0m3.688s sys=0m0.256s 10 real=0m4.064s user=0m3.680s sys=0m0.252s It just seems reasonable to me, that operations 2->10 could take .002 seconds. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1429285 Title: feature request: apt-get update --if-necessary To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/apt/+bug/1429285/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
