dhis2-users team mailing list archive

[Steven Uggowitzer <whotopia@xxxxxxxxx>]

In reference to a discussion thread in this forum from back in November
2014 (below), this might be useful for DHIS2 testing:

Facebook has released an open source application called Augmented Traffic
Control that can simulate the connectivity of a cell phone accessing an app
over a 2G, Edge, 3G, or LTE network. It can also simulate weak and erratic
WiFi connections. The simulations can give engineers an estimate of how
long it would take a user to download a file, for instance, given varying
network connections. It can help engineers re-create problems that crop up
only on very slow networks.

https://code.facebook.com/posts/1561127100804165/augmented-traffic-control-a-tool-to-simulate-network-conditions/
http://www.itworld.com/article/2900674/facebook-engineering-tool-mimics-dodgy-network-connectivity.html
https://github.com/facebook/augmented-traffic-control

Regards,
S



-------------------------------------------------------------------------

   - *To*: Knut Staring <knutst@xxxxxxxxx <knutst@DOMAIN.HIDDEN>>
   - *From*: Steven Uggowitzer <whotopia@xxxxxxxxx <whotopia@DOMAIN.HIDDEN>>
   - *Date*: Tue, 18 Nov 2014 23:40:40 +0300
   - *Cc*: "dhis2-users@xxxxxxxxxxxxxxxxxxx <dhis2-users@DOMAIN.HIDDEN>" <
   dhis2-users@xxxxxxxxxxxxxxxxxxx <dhis2-users@DOMAIN.HIDDEN>>
   - *In-reply-to*: <CAL=8=NiWMttipg0tSxMbO=mnranz4o+NTrogPZ7fEB=
   d2E_DJg@xxxxxxxxxxxxxx>

   There are a variety of possibilities available to virtually simulate
   communications links with limited bandwidth, high latency and packet loss.
   For my own needs, I built a WIFI access point with custom firmware based on
   OpenWRT implementing
KauNet:http://www.kau.se/en/kaunethttps://halshs.archives-ouvertes.fr/file/index/docid/388811/filename/hose-kaunet-iwssc2009.pdf
   If anyone's interested, I could probably virtualise this for qemu or VMWare
   and put it up on GitHub. The simulation algorithm possibilities in this
   solution are great, but it's a bit complicated to set up.

   However, there is perhaps a quick and simple solution, which does not
   simulate quite as accurately, but should give you a better idea about what
   life behind a slow link is like.  You'll need DHIS2 installed on Linux.
   Then have a look at:
   https://gist.github.com/denilsonsa/5176e1c9b6a119594ce0

   This project essentially consists of one shell script that manipulates
   traffic control parameters on a Linux ethernet interface.

   In my case, on my Ubuntu DHIS2 server in VMWare , I simply typed:

   *git clone https://gist.github.com/denilsonsa/5176e1c9b6a119594ce0
   <https://gist.github.com/denilsonsa/5176e1c9b6a119594ce0>*
   *cd 5176e1c9b6a119594ce0*
   *sudo ./slow vsat-busy*

   and presto, accessing the DHIS2 instance (remotely on the IP address for
   ETH0) became very noticeably slower.
   *sudo ./slow modem-2.4k *
   was REALLY slow. Then
   *sudo ./slow reset*
   restores ETH0 to normal.  Help is called up via:
   *./slow -h*
   Usage: slow <network-type> [-d device] [-b bandwidth] [-l latency] [-p drop]

          slow reset
          slow status

   "network-type" type can be:

     GPRS
     GSM
     EDGE
     2.5G
     GPRS
     3G
     4G
     modem-2.4k
     modem-9.6k
     modem-14.4k
     modem-28.8k
     modem-56k
     56k
     T1
     T3
     DSL
     cablemodem
     wifi-a
     wifi-b
     wifi-g
     wifi-n
     eth-10
     eth-100
     eth-1000
     vsat
     vsat-busy

   If you'd like a high level overview of process network utilisation, i.e. to
   make sure that the above script is actually doing it's job, try installing
   NetHogs.  This nice small program (similar to Linux top command) keeps a
   tab on each process' network activity on your system. It also keeps track
   of real time network traffic bandwidth used by each program thread or
   application.

   *sudo apt-get install nethogssudo nethogs*


   Best regards,
   Steven


   --
   --------------------------
   Steven Uggowitzer
   eSHIfT Partner Network,  Entuura Ventures Ltd
   Mob: +41 79 719 4180
   Skype: fendant123
   LinkedIn: http://ch.linkedin.com/in/stevenuggowitzer


   On Sun, Nov 16, 2014 at 5:31 PM, Knut Staring <knutst@xxxxxxxxx> wrote:

   > Hello list,
   >
   > Has anyone been using DHIS2 over a satellite connection, e.g. Thuraya?
   >
   > Bob told me this: "Satellite will be very high latency connection.  Dhis2
   > is well tested for low bandwidth requirements.  I am not sure how much we
   > have tested ajaxy stuff with high latency.  Of course it should work, but
   > there may be some unexpected user experiences."
   >
   > Would be great to hear from anyone who has actually tried this.
   >
   > Thanks,
   > Knut
   >
   > --
   > Knut Staring
   > Dept. of Informatics, University of Oslo
   > Liberia: +231 770 496 123 or +231 886 036 837
   > Norway: +4791880522
   > Skype: knutstar
   > http://dhis2.org
   >
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   >

   References
      - *Experience with Satellite connections for DHIS2?
      <https://lists.launchpad.net/dhis2-users/msg05734.html>*
      From: Knut Staring, 2014-11-16