On Sat, 2 Feb 2019 at 18:54, ducasse <
stepharo@netcourrier.com> wrote:
>
On Sat, 2 Feb 2019 at 11:01, Ben Coman <btc@openinworld.com> wrote:����
>
> > I am getting network errors trying to download latest Pharo Launcher,
>
> can you tell me how so that I try to reproduce it?
Since network performance depends a lot on location, and presuming you'd��
need to be at my house to reproduce my experience,��
I spent the afternoon learning about AWS so I could do some testing from a Australian based cloud box
that you should be able to reproduce fairly easily, since this was my first time using AWS.
With this 10 minute tutorial...
[Launch a Linux Virtual Machine](
https://aws.amazon.com/getting-started/tutorials/launch-a-virtual-machine/)
1. Signed up and signed in
Tip: I struggled a long while looping on "Sign in with root account credentials" until I discovered I needed to use the email address I signed up with, not the account name.
[Edit:] In the top right between account name and support,
pulled down list and selected "Asia Pacfic (Sydney)"
2. Clicked "Launch a virtual machine" �� ��
(note, that only seems to show up for blank account, otherwise its "Launch Instance"
3. Ticked "Free tier only" filter.
+ Selected "Amazon Linux 2 AMI (HVM), SSD Volume Type"�� ��
+ Clicked <Review and Launch> ��(used default t2.micro)
+ Clicked <Launch>
+ From the pull-down selected "Create a new key pair",
gave it a name and clicked <Download Keypair> saved as "SydneyPharoSpeedTest.pem"
+ Clicked <Launch Instance>
+ Clicked <View Instances>
noted instance...
* IP address: 54.252.136.78
* Zone: ap-southeast-2b
* Security Group: Launch Wizard 1
4. On my Windows 10 box, in WSL did...��
$ cd ~/.ssh �� �� �� # if it doesn't exist, first do... �� mkdir -m 700 ~/.ssh
$ cp /mnt/c/Users/Ben/Downloads/SydneyPharoSpeedTest.pem �� ~/.ssh
$ chmod 400 ~/.ssh/SydneyPharoSpeedTest.pem
$ ssh -i ~/.ssh/SydneyPharoSpeedTest.pem ��
ubuntu@54.252.136.78$ cat /etc/os-release
ID="amzn"
ID_LIKE="centos rhel fedora"
GOOD NETWORK BASELINE TEST...
Ignoring any packet loss on poor networks, first testing low bandwidths on a good network
$ vi test.sh
#!/bin/sh
if [ -d out ]; then
�� �� dirdate=`stat -c %z out | awk '{print $1"-"$2}' `
�� �� mv out out.${dirdate}
fi
mkdir out
for RATE in 1000k 500k 200k 100k 50k 20k 10k 5k 2k 1k
do
�� echo $RATE
�� /usr/bin/time -f "%e" -o out/time.$RATE \
�� �� �� ��wget --quiet --limit-rate $RATE
https://files.pharo.org/pharo-launcher/1.6/pharo-launcher-1.6.msi -O out/file.$RATE &
done
$ sh test.sh
monitoring with...
$ cat out/time* | sort -n
$ ls -lS out
results in following table and graphs...
$RATE
(kb/s) |
TIME
(s) |
TIME
(min) |
TIME
(hr) |
| 1000 |
54 |
1 |
0.0 |
| 500 |
105 |
2 |
0.0 |
| 200 |
259 |
4 |
0.1 |
| 100 |
515 |
9 |
0.1 |
| 50 |
1029 |
17 |
0.3 |
| 20 |
2576 |
43 |
0.7 |
| 10 |
5149 |
86 |
1.4 |
| 5 |
10527 |
175 |
2.9 |
Wow that surprised me.�� I'm not sure what the behaviour of file servers at low bandwidth should be,
but intuitively the above seems odd.�� In the past troubleshooting seems to have been��
focused on the cause of slow speeds, but these can occur for many reasons unrelated to the��
the file server.�� The above test ignores cause to isolate behaviour at slow speeds.
I forgot my own download speed yesterday (today is okay), but here is another sample...
"(in Argentina) it is really slow ... 3.5KB/s ... average 10KB/s".
I would hope that download time was near linear with speed all the way down to 1kb/s.��
Anyone have some sysadmins they can lean on to understand if that is realistic?
The straightness of the line using a log-log axis makes it seem like policy rather than physics.
<download-speed(log).png>
HTH,
cheers -ben