Re: F12: Yum - network disconnects spins it's wheels.

Daniel B. Thurman wrote:
  

On 02/25/2010 09:34 PM, Ed Greshko wrote:
  
    

Tony Nelson wrote:
   
    
      

On 10-02-25 21:37:58, Ed Greshko wrote:
  ...

     
      
        

I can't conceive of a situation where usage of http or ftp protocol
would interact to "smack" an imap connection.

To me, based on your observations, I'm getting the feeling you may
have a strange network problem that may be local to you or within
your ISP close to you.  As I said, I'd be dragging out wireshark.

       
        
          

It's not FastestMirror, it's the mirror it's choosing to use.  If he
figures out which one, he can blacklist it.


     
      
        

That is what the case was in my situation although maybe I didn't spell
it out.  However, I did say that Singapore was causing an issue for me
and I added the line "exclude=.gov, .sg" to my fastestmirror.conf.

But, when he says that his IMAP connection is *also* being affected then
I can't conjure a situation where yum would have an impact on IMAP
    
      

I can try to find out if it is a mirror problem, but then again, I thought
that mirrors were randomly chosen and if a mirror is not responding
properly or whatever it is, the offending mirror should have been dropped
and another mirror tried.  From past Yum versions, I have seen this to
be the case, and I have not seen any such thing with F12's Yum version
which lead me to question if mirror testing/switching code was
dropped?  I hope I am wrong in my assumptions.
  
    

AFAIK, haven't done any research, without FM mirrors are chosen more or
less at random.  With FM a list is generated and the fastest mirror
found.  Then every time yum is run the list is used.
  

Is it possible that the network is somehow using maximum bandwidth
preventing network access to other apps?  The IMAP network break
seemed to prevent IMAP client connectivity temporarily and once yum
stopped, IMAP client connections quickly resumed.

I have a pretty quiet network and it seems to me, that somehow running
yum with FM causes problems.  Removing FM seems to work but it is
not maxing out the bandwidth.  For example, with FM, it is hitting hard
at around 300-320KB/s but without it, it is hitting around 200-290KB/s
which is notably slower as you watch the downloads.

  
    

First, the only thing that FM does is determine what mirror it feels
will get your the best download speed.  That is all that is does. 
Period, end of story.  If you use FM and you get higher speed downloads
on updates then it is doing its job.

If high download speeds are really causing problems, not just hogging
your connection and slowing down other types of downloads, then a
network problem could exist.

What kind of connection do you have?  I've got DSL with advertised
speeds of 2MB/515Kb.  I run "slingplayer" on my Vista system and viewing
is crisp and clear and no noticeable impact on browsing.  That is, until
I start downloading a torrent or two while simultaneously  doing
updates.  Then the browsing is slower, the TV isn't as clear.  But that
is to be expected.  But, nothing dies.

If you are getting a situation where a high speed download results in
everything degrading into being unusable then a hardware problem in your
path could exist.  This was years ago, but I once had a problem where a
router suffered from buffer overruns when traffic was extremely high. 
It  would throttle connections and start throwing away data resulting in
many retransmissions.  To make a long story short, it couldn't
gracefully recover and caused high packet loss in spikes.  Made finding
the problem hard.