A quick set of notes looking into Ubuntu mirror locations for South Africa from my home fiber (Vumatel). The examples should apply in general.
There are two phases
- Getting lists of packages
- The actual package download
When testing performance of package list info downloads via upt-get update, clear previous package info downloaded. If this isn't done, cached package info could skew results.
sudo rm -rf /var/lib/apt/lists/*
The Software & Updates (software-properties-gtk) tool has a 'Dowload from' button. Choose 'Other' and look for the 'Select best server' button.
ubuntu.mirror.neology.co.za was selected as the best choice based on the 'Software & Updates' tool's methods.
Official Archive Mirrors for Ubuntu provides info on mirrors, the link speed and how up to date they are.
E.g.
| South Africa | 2 Gbps | 3 mirrors | |
|---|---|---|---|
| WIRUlink | http ftp rsync | 1 Gbps | Up to date |
| Neology | http ftp rsync | 1 Gbps | Up to date |
| UCT LEG | http ftp rsync | 10 Mbps | Up to date |
Another option is to check (http://mirrors.ubuntu.com/ZA.txt)
http://ftp.leg.uct.ac.za/ubuntu/
http://mirror.wiru.co.za/ubuntu/
http://ubuntu.mirror.neology.co.za/ubuntu/
http://archive.ubuntu.com/ubuntu/
And there are some unofficial mirrors?
http://ubuntu.saix.net/ubuntu-archive/
As per (https://launchpad.net/ubuntu/+mirror/ftp.saix.net-archive), it looks behind.
A traceroute will help check latency and nearest hop (but that doesn't necessairly imply best bandwidth)
To use namp to traceroute
$ export targets=$(curl -s http://mirrors.ubuntu.com/ZA.txt | grep -oP '(?<=^http://)[^/]+') && sudo -E nmap -Pn -sT -p80 --traceroute -oX za.ubuntu.nmap.xml $targets za.archive.ubuntu.comNote, the above:
- gets a list of mirrors and extracts the FQDNs into the
targetsvariable which is exported so that it can be passed along via sudo nmap - nmap requires root for the traceroute feature
- za.archive.ubuntu.com is appended to the list, given this seems to be the official update site when installing Ubuntu and setting the region as South Africa
- *.archive.ubuntu.com have some or the other network security mechanism the prevents nmap host discovery and port probe on port 80, hence the need to
-Pnto force the traceroute
The scan traceroute results can be visualized with zenmap. Zenmap provides nice visual queues
- Outermost circle lines show the furtherest hosts
- The thicker the blue line, the more latency
- Centered perspective from the router that was common to most routes
zenmap za.ubuntu.nmap.xml
Observations:
- mirror.wiru.co.za was closest
- 9 hops away (lowest)
- ~2 ms latency (lowest)
- ubuntu.mirror.neology.co.za was 2nd closest
- za.archive.ubuntu.com was even further than archive.ubuntu.com!
- 13 hops away (highest)
- ~190 ms latency (highest)
Using the mirror file and appending the za.archive.ubuntu.com, I tested downloading the updates package list for my architecture (amd64):
$ for m in $(curl -s http://mirrors.ubuntu.com/ZA.txt) http://za.archive.ubuntu.com/ubuntu; do echo $m; curl "$m/dists/xenial-updates/Contents-amd64.gz" > /dev/null; done
http://mirror.wiru.co.za/ubuntu/
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
100 5991k 100 5991k 0 0 10.4M 0 --:--:-- --:--:-- --:--:-- 10.4M
http://ubuntu.mirror.neology.co.za/ubuntu/
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
100 5991k 100 5991k 0 0 1106k 0 0:00:05 0:00:05 --:--:-- 984k
http://ftp.leg.uct.ac.za/ubuntu/
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
100 5991k 100 5991k 0 0 561k 0 0:00:10 0:00:10 --:--:-- 595k
http://archive.ubuntu.com/ubuntu/
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
100 5991k 100 5991k 0 0 1556k 0 0:00:03 0:00:03 --:--:-- 1556k
http://za.archive.ubuntu.com/ubuntu
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
100 5991k 100 5991k 0 0 298k 0 0:00:20 0:00:20 --:--:-- 286kObservations
- ~10MB/s average was the best, and approaching the maximum throughput of my current fiber line's throughput (~100Mbit/s)
- za.archive.ubuntu.com, the default when you do a fresh install, was the worst!
- Even though archive.ubuntu.com has the second highest number of hops and latency, and tracerouted through a ste in london, onto the US, it showed the 2nd best throughput, beating out all other local mirrors, except one.
Limitations:
- The above only simulated some of the package list download process, not an actual package fetch.
- And many more samples are needed (I'd be shot by a statistician)
The 'Software & Updates' and my own traceroute plus once-off curl download speed test didn't 100% agree, but both found what seems to be the top two local mirrors. Obviously:
- Multiple samples over various time ranges are needed
- As well as testing actual package downloads
Oddly, za.archive.ubuntu.com is the furtherest away and the slowest. Maybe it has the highest network load from SA given it's the default mirror if Ubuntu is installed with South Africa as the region.
apt-select is an example of a tool that automates many of the steps above, except and actual download speed test. A feature request for that has already been logged.
