[CentOS-devel] yum and fastestmirror

Tue Jun 17 22:56:45 UTC 2008
Wojciech Pilorz <wpilorz at gmail.com>

On Tue, Jun 17, 2008 at 4:12 PM, Karanbir Singh <mail-lists at karan.org> wrote:
> Wojciech Pilorz wrote:
>> yum-fastestmirror does not work behind some restrictive (oppresive?)
>> firewall
>> configuration.
> if yum itself is able to make http/ftp connects to a remote host, I dont see
> why yum-fastestmirror might have an issue, can you provide some specifics
> about what broke and how ?

I have an environment where access to Internet is filtered, and only allowed
through a squid proxy (and DNS queries only to a local DNS server).
yum needs proxy line in config file to work at all.

If I run yum-fastestmirror in such environment, /var/cache/yum/timedhosts.txt
contains 99999999999 in each entry (as direct connect to remote site
always fails).
So yum still does work, just the timing information is useless.

>> Also, at least some time ago, fastestmirror was very address-space hungry,
>>  and caused yum to die if ulimit on address-space or stack-spaceset
>>  set to anything below 1Gig or more (well, that was on fedora
>>  with a very long list of mirrors, and fastestmirror created
>>  a large number of thread, perhaps one for a mirror).
> Well, this isnt Fedora. So if you have an issue on CentOS with something
> similar its worth looking at.

Fedora had at some moment over 100 mirrors in mirrorlist returned
to yum. So when yum-fastestmirror decided it needs to create /
recreate timedhosts file,
it started that many threads at once, each allocating some 15 MB of stack
space, IIRC.
It seems CentOS mirrorlist returned to yum contains not more than 10-15
entries, so this should not be a problem (if the number of mirrors
yum gets is always that low on CentOS).

Thank you,