[Mageia-dev] Proposal for Mageia: implement bitorrent protocol to allow updates download

Wed Jan 12 13:31:43 CET 2011

Le mercredi 12 janvier 2011 à 08:05 +0100, Thierry Vignaud a écrit :
+> On 12 January 2011 04:29, Michael Scherer <misc at zarb.org> wrote:
+> > For example, distrib-coffee could blacklist you if you do this, if you
+> > are not alone on your network connexion. And when we deployed this
+> > measure to protect the server, the limit was 2 connexion per address,
+> > since this was taking too much ressources on the old server ( each http
+> > request taking 1 process and so memory ).
+> 
+> switching to nginx would help that
+
+According to the current mirror maintainer, the problem is not only on
+http server memory usage ( I do use nginx myself on my own servers and
+indeed, that would alleviate this part of the issue ).
+
+It is also that doing random access to file result in random seek on the
+raid array, and on a regular scsi disk ( not on ssd but ssd is not cheap
+for the moment ), this is more disrupting since the head of the disk is
+constantly moving to seek the block to fetch. 
+
+Fetching continuous block from the disk is faster, since there is no
+delay. Fetching from random part of the disk is more problematic.
+
+And the same goes when done on multiple servers. It is lighter on the
+overall ressources to download on one mirror and stick to it than open 5
+connexions and do 5 random seeks on 5 different disk.
+
+-- 
+Michael Scherer
+
+