Are Thin Clients Right for Your Library?

Publication Date01 March 2006
Date01 March 2006
AuthorRobert Sand
SubjectLibrary & information science
Are Thin Clients Right for Your Library?
Robert Sand
14 LIBRARY HITECH NEWS Number 3 2006, pp. 14-15, #Emerald Group Publishing Limited, 0741-9058, DOI 10.1108/07419050610668133
In the last five to seven years the
computer industry has been trying to
contract into a central service mode
instead of the distributed service mode
of the client server technology. Thin
clients in the past were called dumb
terminals but are now a little bit smarter
than they were in the past because of the
added features and the capability of
using older personal computers to run
web based applications. One of these
thin clients is the Sun Microsystems
Sunray. The Sunray comes in a few
different versions but all do the same
thing, display an application running on
a centralized server. The Sunray can
also provide sound, printing, and access
to zip drives, memory fobs, and some
digital cameras. The library at the
University of Minnesota Duluth (UMD)
has approximately 275 Sunray one
clients attached to four centralized
servers. A total of 15 of these Sunrays
are available to the general community
to walk in and use to search the library
resources and surf the web.
There are four areas of concern when
looking at a thin client for your library,
software, hardware, network, and
security. The two largest applications
that your library clients will need are
word processing software, and web
browser software and all of the
necessary plug-ins for the web
browsers. When dealing with the thin
client the software is managed on the
servers to which the thin client attaches.
This centralized method of application
deployment is a savings in setup and
disk storage because it is in one place
and everybody accesses a single copy of
the applications. Most users of the web
require that their web browsers have at
least Macromedia Flash, Java,
RealAudio, and Acrobat Reader
available. Having a centralized location
for the web browser software also gives
the administrator of the thin client the
ability to easily update and add browser
plugins for all users at one time.
One thing to look at when
considering using thin clients is
whether or not your applications can be
stored in a centralized location and if
the user installation is minimal in
regards to the amount of storage needed
for each user. The UMD library
currently uses the Mozilla web browser
and OpenOffice office application
package. You can use the Microsoft
Office applications as well and I will
cover those later.
The hardware that runs the thin
client server software and applications
needs to be scaled to the number of
clients the server will service at any
given moment. We have found that
anytime you use web applications like
web browsers the normal
recommendations by the thin client
software is too high. All four of the
servers we use are four processor
servers with 16GB of main memory.
Even with this type of server footprint
the number of clients we can serve is a
maximum of thirty to forty clients per
server. This also depends upon the
network that is servicing the traffic for
the thin clients, the servers, and the
internet connection. If any one of these
connections is slow, it will also slow
down all of the clients attached to the
servers. The network connections to the
thin client should be at the maximum
that the client can handle. In most cases
this will be a 100Mb/s connection, but
the server connection should be at least
1Gb/s or multiple 100Mb/s
connections. In the case of the Sunray
thin client the most it can do is 100Mb/s
and all of the data to and from the client
is using the UDP (User Datagram
Protocol) protocol. UDP is not a stateful
protocol so if the network is clogged
and the client is doing a lot of graphics,
streaming video or audio the packets
will be dropped which will make audio
and video unusable.
Another network consideration
would be the dns and dhcp needed for
the thin client. In the case of the Sunray
thin client you will either have to put
the Sunrays on a private network
attached to the server or on a public
network. The public network will
require that the dhcp requests for the
thin client to go to a specific dhcp
server. The Sunray server software
installs a dhcp server along with the
installation and can be used if you need
it. We have found that putting the dhcp
server on server separate from the
Sunray server software gives us the
ability to make server changes easily
without major amounts of service
outages. The Sunray server dhcp
software gives out the ip address of the
client, the ip address of the server that
will handle the authentication for the
client, the server that will have the
session for the client, the current
firmware level available for the client,
and where the client can get new
firmware if needed. A private network
setup of the Sunray server software is
the default. To setup the server software
to use a public network is a little bit
more work in the installation and setup
In our installation security was one
of the most important factors next to
cost in setting up the Sunray thin client.
In our situation we have a community
population who are able to walk into
our library to use the electronic card
catalog services. This presents a
problem when the rest of the campus
must use a secure login and have a
secure connection to the local network
and the internet. The Sunray server
software offers a kiosk application that
allows specific applications to be used
on specific thin clients. In our case, we
allow only a web browser to be used on
a kiosk thin client. This allows not only
our walk in clients to use the library but
also allows our faculty and staff to walk
up and easily look up books or
resources, read e-mail via a web based
e-mail client or anything else that can

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