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.
- To: Knut Staring knutst@xxxxxxxxx
- From: Steven Uggowitzer whotopia@xxxxxxxxx
- Date: Tue, 18 Nov 2014 23:40:40 +0300
- Cc: “dhis2-users@xxxxxxxxxxxxxxxxxxx” dhis2-users@xxxxxxxxxxxxxxxxxxx
- In-reply-to: CAL=8=NiWMttipg0tSxMbO=mnranz4o+NTrogPZ7fEB=d2E_DJg@mail.gmail.com
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/kaunet](http://www.kau.se/en/kaunet) [https://halshs.archives-ouvertes.fr/file/index/docid/388811/filename/hose-kaunet-iwssc2009.pdf](https://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](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) <[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](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](http://dhis2.org/) > > _______________________________________________ > Mailing list: [https://launchpad.net/~dhis2-users](https://launchpad.net/~dhis2-users) > Post to : dhis2-users@xxxxxxxxxxxxxxxxxxx > Unsubscribe : [https://launchpad.net/~dhis2-users](https://launchpad.net/~dhis2-users) > More help : [https://help.launchpad.net/ListHelp](https://help.launchpad.net/ListHelp) > >
Experience with Satellite connections for DHIS2?
From: Knut Staring, 2014-11-16