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.
There’s no cable in Solomons. Satellites are used in every province. We do have all sorts of problems running the analytics especially but aggregate data entry is mostly OK. Latency can be high, anywhere from 1200-1800ms on average depending on the province. Did you have some specific questions about this?
Nick
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.
Great Nick, I should of course have thought of the Solomons immediately. It would be good to have your advice on the specific models we are thinking of for Liberia, I will send you some material off-list.
There’s no cable in Solomons. Satellites are used in every province. We do have all sorts of problems running the analytics especially but aggregate data entry is mostly OK. Latency can be high, anywhere from 1200-1800ms on average depending on the province. Did you have some specific questions about this?
Nick
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.
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
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:
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:
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]
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.
On Sun, Nov 16, 2014 at 5:31 PM, Knut Staring <knutst@gmail.com> 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