Feature changed by: Peter Poeml (poeml)
Feature #305320, revision 14
Title: Show accessed mirror(s)
openSUSE-11.1: Rejected by Stanislav Visnovsky
Do you want the information in the log or to be shown in e.g. zypper -vvv ? Shown, in normal output. It is already in some log I believe, I don't know which one exactly anymore though. Thing is, users won't be able to tell us anything useful if they weren't shown the information. And later it is not reproducible. At least in a failure situation the URLs must be shown. That alone wouldn't give us the chance to find out about slow mirrors, but at least it would allow to debug problems. Real life example #1: If a mirror is behind a firewall that lets every 10th connection stall (so the transfer hangs or the connection is reset), it usually takes weeks (!) to find out about it. But it hits virtually every user from mirrors country during the time. We have had this 4 times during the last 18 months. Real life example #2: I got feedback from someone who did a network install of openSUSE 11.0 from download.opensuse.org, located in the US. He had to let it running overnight because it took a long time. Next morning, the install hadn't even completed. YaST was hanging and waiting for somebody to hit retry. Problem is, it took us a lot of work to find out which mirror was at fault. We actually had to repeat the install, I had to follow the log and live watching his machine accessing download.opensuse.org, to see where it was redirected, and where it spent most time (while downloading some package). We found a mirror which was really slow, and I could disable it. I have a suspicion though, that we have more such mirrors, because I have got some similar reports from recently. But how to find out? People only complain about slowness, without the ability to give any useful detail. See http://news.opensuse.org/2008/09/23/upcoming-factory-changes/#comments (http://news.opensuse.org/2008/09/23/upcoming-factory-changes/#comments) for examples of this.
Discussion: #1: Susanne Oberhauser (froh) (2008-10-01 15:16:30) What if we focussed on something like torrent for distributing packages instead? AFAICT these p2p network technologies have mechanisms to recover from missing fragments, i.e. failing servers. In that world, todays mirrors would be strong and almost always present peers in the network. #2: Peter Poeml (poeml) (2008-10-01 15:30:56) (reply to #1) Torrents are not efficient for files of this small size. Another concern is that, on large scale, the reasonability of P2P traffic with regard to network topology is questionable; confer to what's called the Application-Layer Traffic Optimization (ALTO) problem. See http://alto.tilab.com/ (http://alto.tilab.com/) . There are working examples where e.g. university have rolled out a P2P update distribution campus-wide; in a controlled limited environment this is feasible, but not across the Internet. Further, note that libzypp in 11.1 has preliminary support for using metalinks for downlaods. Metalink clients recover nicely from missing fragments. See http://en.opensuse.org/Libzypp/Failover (http://en.opensuse.org/Libzypp/Failover) . #3: Mark Goldstein (markgo) (2008-10-04 17:20:42) Other usage of this feature would be possibility of "blacklisting" servers with persistent problems. (See thread in opensuse list "Is it possible to "blacklist" specific download server in Yast?" ). As Carlos E. R. suggested other useful option could be for YaST/zypper to fail gracefully requesting another server to the redirector on failure on the one it gave use previously. #4: Peter Poeml (poeml) (2008-10-04 17:55:14) (reply to #3) Gracefully falling back to other mirrors is already being implemented (currently in prototype stage) by way of http://en.opensuse.org/Libzypp/Failover (http://en.opensuse.org/Libzypp/Failover) . The feature of blacklisting a specific mirrors is included in that proposal, and I have added it explicitely. #5: Gerald Pfeifer (geraldpfeifer) (2008-10-30 17:33:25) Looking at the discussion on opensuse-factory and my own experience, I also see this as high priority for 11.2. + #6: Peter Poeml (poeml) (2009-01-27 20:39:59) + Just for the record, the way to enable logging that makes mirrors show + up in the log seems to be: + $ ZYPP_MEDIA_CURL_DEBUG=1 zypper ... + Cf. http://en.opensuse.org/Debugging_YaST -- openSUSE Feature: https://features.opensuse.org/?rm=feature_show&id=305320