dhis2-kenya team mailing list archive

[Lars Helge Øverland <larshelge@xxxxxxxxx>]

Hi,

during the training on Tuesday we had a very good discussion on our approach
for server hosting.

The short summary is that we want to continue to host the primary instance
of DHIS in the "clouds" (with our external provider Linode) while we set up
a mirror server locally at the Ministry of Health.

This way we try to combine the benefits of reliable and secure hosting of
the "live" system while covering the requirement for local physical access
to the data and the need for building local capacity for server
administration.

We have now written a section on this in the DHIS implementation guide which
might be relevant for this discussion, I am copying it below for those
interested.

best regards, Lars






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

Server hosting

The online deployment approach raises the question of where and how to host
the server which will run the DHIS 2 application. Typically there are
several options:

1. Internal hosting within the Ministry of Health
2. Hosting within a government data centre
3. Hosting through an external hosting company

The main reason for choosing the first option is often political motivation
for having “physical ownership” of the database. This is perceived as
important by many in order to “own” and control the data. There is also a
wish to build local capacity for server administration related to
sustainability of the project. This is often a donor-driven initiatives as
it is perceived as a concrete and helpful mission.

Regarding the second option, some places a government data centre is
constructed with a view to promoting and improving the use and accessibility
of public data. Another reason is that a proliferation of internal server
environments is very resource demanding and it is more effective to
establish centralized infrastructure and capacity.

Regarding external hosting there is lately a move towards outsourcing the
operation and administration of computer resources to an external provider,
where those resources are accessed over the network, popularly referred to
as “cloud computing” or “software as a service”. Those resources are
typically accessed over the Internet using a web browser.

The primary goal for an online server deployment is provide long-term stable
and high-performance accessibility to the intended services. When deciding
which option to choose for server environment there are many aspects to
consider:

1. Capacity for server administration and operation. There must be human
resources with general skills in server administration and in the specific
technologies used for the application providing the services. Examples of
such technologies are web servers and database management platforms.

2. Reliable solutions for automated backups, including local off-server and
remote backup.

3. Stable connectivity and high network bandwidth for traffic to and from
the server.

4. Stable power supply including a backup solution.

5. Secure environment for the physical server regarding issues such as
access, theft and fire.

6. Presence of a disaster recovery plan. This plan must contain a realistic
strategy for making sure that the service will be only suffering short
down-times in the events of hardware failures, network downtime and more.

7. Feasible, powerful and robust hardware.

All of these aspects must be covered in order to create an appropriate
hosting environment. The hardware requirement is deliberately put last since
there is a clear tendency to give it too much attention.

Looking back at the three main hosting options, experience from
implementation missions in developing countries suggests that all of the
hosting aspects are rarely present in option one and two at a feasible
level. Reaching an acceptable level in all these aspects is challenging in
terms of both human resources and money, especially when compared to the
cost of option three. It has the benefit that is accommodates the mentioned
political aspects and building local capacity for server administration, on
the other hand can this be provided for in alternative ways.

Option three - external hosting - has the benefit that it supports all of
the mentioned hosting aspects at a very affordable price. Several hosting
providers - of virtual servers or software as a service - offer reliable
services for running most kinds of applications. Example of such providers
are Linode and Amazon Web Services. Administration of such servers happens
over a network connection, which most often anyway is the case with local
server administration. The physical location of the server in this case
becomes irrelevant as that such providers offer services in most parts of
the world.

An approach for combining the benefits of external hosting with the need for
local hosting and physical ownership is to use an external hosting provider
for the primary transactional system, while mirroring this server to a
locally hosted server which is used for read-only purposes such as data
analysis. This server can then be accessed over the intranet independent of
Internet access and fulfill the requirement for physical access. This
implies that the transactional system is operating in an reliable and secure
environment while the data still can be considered to be hosted locally
within the Ministry of Health. With this approach the need for building
local capacity for server administration can be covered - a local ICT team
can be assigned with operating the server independently of the physical
location of where it is hosted.