to find fastest debian mirror

[Andrea Mennucci <mennucci@cibs.sns.it>]

hello to everybody

I had a strange slowdown on the internet, and
I wanted to locate the fastest debian mirror for me so I wrote a simple
 shell script  that I call   sort_mirrors_by_speed

this script takes as its argument  the file README.mirrors
 (that can be downloaded from the debian ftp sites), extracts the list
of hosts and pings them all (it takes roughly 30 seconds, since
it parallelizes) then sorts the output by fastest time

I think it would be fantastic if this script could be made
part of   dpkg-ftp , (lets say, as an option when in dselect
 you choose  Access and then ftp);
 so  the average user could ask  dselect to test the mirror speeds and
then choose the  fastest for its network from a convenient menu
(of course this means that the file README.mirrors should be shipped as a
part of dpkg-ftp , and maybe updated when Update is chosen)


hope you will find this useful

a.m.


#!/bin/sh

# sort_mirrors_by_speed     by A.Mennucci Nov 97
#
# this program is subject to the
#  GNU general public license

#
# this program will scan the file in $1 using
#  grep "\.[a-zA-Z]*:" $1 | awk '{print $1}' 
#  to find mirror site host names.
#
#  the string before the  :  character is considered to be a 
#   mirror site host name 
#
#  Mirror sites are pinged and statistics  are collected and sorted
#


if [ "$1" = "-h" -o "$1" = "--help" ] ; then
 echo Usage: $0 mirrorfile
 echo " Argument must be the file README.mirrors "
 echo "      containing a list of debian mirrors."
 echo " This program will ping all mirrors with 4 packets"
 echo "  to test their speed and reliability, and then will "
 echo "  sort the result, put it in file mirrors_by_speed and show the best."
 exit 0
fi


tmpdir=~/tmp

# warning: using the directory /tmp and running this script
# as root is a potential security problem

if ! [ -w  $tmpdir ] ; then
 echo $0 ERROR dir $tmpdir is not writable
 echo please create it if it does not exist
 exit 1 
fi


if [ ! -r "$1" -o "$1" = "" ] ; then
 echo $0 ERROR Give as argument the file README.mirrors 
 echo "      containing a list of debian mirrors"
 exit 1 
fi
if [ -r mirrors_by_speed ] ; then
  echo $0 ERROR the file  mirrors_by_speed already exists
  exit 1
fi  

n=0

echo -n "Testing "
grep "\.[a-zA-Z]*:" $1 | awk '{print $1}'   | \
   wc --lines |  tr "\n" " "
echo " debian mirror sites for speed and reliability."
echo -n "Tests done : "
for i in ` grep "\.[a-zA-Z]*:" $1 | awk '{print $1}'  ` ;
 do
  n=`expr $n + 1 `
   (
   h=$n
   #echo TEST $h for  $i
   if ping -c 6 `echo "$i" | cut -d: -f1  `  > $tmpdir/ping$$_$h ; then
    
    grep "round-trip" $tmpdir/ping$$_$h |\
        cut -d/ -f 4 | tr "\n" " "  > $tmpdir/mirrors_by_speed_$h
    echo -n " ms AVERAGE ," >> $tmpdir/mirrors_by_speed_$h 
    grep "received" $tmpdir/ping$$_$h |\
        cut -d"," -f 3 | tr "\n" "," >> $tmpdir/mirrors_by_speed_$h
    echo " SITE $i"                  >> $tmpdir/mirrors_by_speed_$h
    #cat $tmpdir/mirrors_by_speed_$h
    cat $tmpdir/mirrors_by_speed_$h >> mirrors_by_speed
    rm $tmpdir/mirrors_by_speed_$h
   fi 
   rm $tmpdir/ping$$_$h
   echo -n "$h "
   ) &
   # we do not want to flood the net; we test 30 sites at a time
   # then we wait 8 seconds so that most of the pings will be done
   if [ `expr $n % 30 ` = 0 ] ; then sleep 8 ; fi
   
 done
wait
 echo "."
 echo "Fastest mirrors are: "
 mv mirrors_by_speed   mirrors_by_speed~
 sort -n  mirrors_by_speed~ >  mirrors_by_speed 
 head  mirrors_by_speed