Data Centre Update

Here’s what the data centre looked like on the 2nd July. The air conditioning units are being fitted at the back, the false ceiling frame is being fitted and the walls are painted. Holes have been cut in the raised floor for the power and data cables but they are hidden under the floor covering. There is still a long way to go but it is starting to look like a data centre.
Data Centre July 2 2010

The following picture is either a cutting edge experiment in ultra green data centre design, or it is the new racks being delivered. 🙂
Green Data Centre

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Data Centre Update

Blogs posts are like buses, nothing for ages and then two or more arrive one after the other. I had a quick site visit on Friday afternoon and managed to snap a picture of the progress made on the data centre so far. Still not much to look at in terms of IT equipment but things will move quite rapidly over the next three or four weeks.

The two door are actually cupboards which will cover some cabling, pipe work and fire supression, the gap in between the two doors will where the air conditioning units will be fitted. The floor protectors are hiding the raised computer room floor.

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Core Services – Summer 2010

It has been a while since I last blogged anything so I thought I would take the opportunity to let you know what the Core Services team is planning for the summer. Our biggest project this year is our new data centre, it is currently under construction and should be completed by early July. It will be Edge Hill’s most sophisticated data centre to date and has been designed to follow current best practices for data centres. On completion the Core Services team will be moving the majority of the servers to this new data centre, this should then allow the existing data centre to be redesigned to make it more efficient. There will be minimal downtime involved, but any downtime will be publicised in advance. I am going to be taking pictures of build progress as we go along but the first picture is fairly unexciting (probably to most people except me).
Data Centre

We have recently updated our virtualisation software to VMware Vsphere and at last count we were running around 150 virtual servers. Most of the features require more explanation than a few lines to explain properly, but one of the features we are taking advantage of is the power management. VMware can monitor the IT load on virtual servers and physical server hosts, when the IT load drops the software moves virtual servers around to make best use of resources. Once this has been done VMware can then shut down physical servers that are not being used. This means that at night and off-peak times when demand for IT services is lower the software saves money by reducing electricity costs and also reducing any associated CO2 emissions. VMware continues to play a major part in our server strategy and all new IT servers will now be virtual unless there is a specific business case for the servers to be physical.

Over the summer we also aim to finish our student email migration from Groupwise to Googlemail, this project began last year with the introduction of Googlemail for first year students. We have already made preparations for the migration but there is a lot of work to do in order to notify the students before we can start the migration. I’ll be working closely with Learning Services to make sure this final stage of the project goes to plan.

And finally we are due to commission our second Compellent SAN in the next few weeks. Once the new data centre is complete the new SAN will not only provide us with some additional capacity, it will also give us resilience, enhanced backup capabilities and some facilities for disaster recovery. I had hoped that we would blog more about the Compellent SAN but new projects keep coming in. Our first Compellent SAN now holds most of our virtual machines and other files like staff home directories and staff shared directories. Once the new data centre is complete and the new SAN is commissioned I will post something around what the SAN does and why we chose Compellent.

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Core Services Update

Well it’s almost November and the blog has been a bit quiet recently! It’s also been a while since I put something up so I thought I’d give you a brief update on what we’ve been doing recently and what we are planning for next year.

One of the biggest projects this year has been the introduction of GoogleMail for students. All new 1st year students are now live on the google domain. The last of the Google/Groupwise integration work is being completed soon, the most important part of this is to share contacts between Groupwise and GoogleMail. We hope to offer migration to the google domain to all students next year, the aim being that by the end of 2010 all students will be using the Google mail domain.

We’ve also been working to improve the SunRay infrastructure with the addition of new servers, improved access times to staff home directories and staff shared directories and we’ve been working hard to reduce the carbon emissions of our existing data centre. Server virtualisation is now key to our server infrastructure; we have also been following quite an aggressive server retirement plan to reduce our physical estate of servers.

We’ve recently purchased a new storage solution from a company called Compellent, this is going live on Sunday 8th November and will initially store all staff home directories and shared files. I’m sure the team will blog shortly about the new Compellent SAN so I won’t go into too much detail here.

Next year will see our new data centre built and we are hoping to make this as green as we possibly can. We are currently working with facilities management to analyse the power usage and heat generated by our current data centre, this data will then advise the design of the new data centre. Next year will see more virtualisation and less physical servers being purchased. We are also looking at giving some SunRay users more control over their desktops and the ability to install their own applications.

That’s it from me at the moment, I’m off to twist some arms and hopefully the blog will liven up a bit pretty soon with some more posts from the team!

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SunRay Update 8

Following some of my previous calculations on power efficiency, carbon footprints and comments about heat/noise differences between Sunrays and PC’s; I mused we could factor in a ‘system’ we all know well – ourselves.

Heating in has become redundant in PC labs, with the computers becoming increasingly powerful and dispersing more and more heat, labs are designed with cooling as a priority.

So, as you might expect, Sunrays are changing the way we are (or should) looking at labs. If we take an average lab with two dozen PC’s, it’s easy to guess what is generating the most heat. But would you have guessed in a Sunray lab, the answer is the users!

In order to keep this as simplified as possible, various assumptions have been made; such that these figures are theoretical within a closed system, people are ‘average’ (including fitness, health and calorie intake), environment is ‘average’ and a whole flurry of other ‘ideal situations’.

Statistical assumptions:
1 watt = 3.413 Btu/h
Average person = 58.2 w/m2 (1 met)

British Thermal Unit (BTU): “A BTU is defined as the amount of heat required to raise the temperature of one pound of liquid water by one degree from 60° to 61°Fahrenheit at a constant pressure of one atmosphere.”
Initially we calculation the surface area from our person, I’ll use DuBois’ formula:

BSA = (W 0.425 x H 0.725) x 0.007184

(Weight is in kilograms and the height is in centimetres).
Thus we take our candidate standing at 60Kg and 170cm. Resulting in 1.7m2 surface area of the integumentary system – the skin.
Due to the dynamics of our ‘warmblooded’ organisms, our heat loss is dependant on our metabolic rate. Essentially the ability to generate heat is a result of our muscular activity, which could be considered as a by product of work (force x distance).
So at rest, we can assume our ‘average’ person produces per hour:
58.2 x 1.7 = 99 watts = 338 btu/h.
Each Sunray (including TFT monitor) consumes 41 W.
41 x 3.413 = 140 btu/h

Each PC (including TFT monitor) consumes 105 W.
105 x 3.413 = 358 btu/h


So if you are budgeting for cooling labs, you might consider getting over 2.5 Sunrays to every 1 PC. However, you might need to use this saving in the winter to heat the cold labs! Otherwise, fill the room full of people – the cheapest way to heat a room!

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Sunray Education Desktop Community Forum 2009

Perihelion – The point in its orbit where a planet is closest to the Sun – occurs for Earth in January. By coincidence, January also saw the gathering of Sun Microsystems and the education community to discuss the present and future of Sunray Systems.

An excellent day to meet, greet and exchange ideas, methods and plans for Sunrays across a range of educational establishments, Sun engineers and resellers.

Moreover it was enlightening to hear where Sun Microsystems are planning to take Sunrays in the future, bugs which are being fixed and functionality to be added.

Given the responses from peers in the community, there is no denying the movement towards the use of Sunrays and SGD.

By no means are we the first or largest implementation of Sunrays, but we do seem to have a fairly unique setup and really are trying to get the most out of our systems. It is humbling to see and hear the feedback and acknowledgement of content of this blog, and I’m pleased that it is being used as a resource for information across the world.

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SunRay Update 7

Although the Java menu seemed like a good option, when we ran the figures, it seemed the overhead really was a little excessive when one considers that no extra functionality was provided; only some smoother edges.

These figures were taken from a sample and represent estimates.

The Tcl menu (menu displayed, not connected to windows): 30Mb.
The Tcl menu (menu is still active in background, user connected to windows): 45Mb.

The Java menu (menu displayed, not connected to windows): 70Mb.
The Java menu (menu is still active in background, user connected to windows): 90Mb.

We can reduce the Java overhead by roughly 20Mb if we remove the Java window manager, this will reduce the functionality of the JFrame, but it is a worthy sacrifice for the memory we save.

That brings our new totals for the Java menu to 50Mb (not logged in) and 70Mb (logged in).

So assuming we have removed the Java windows manager, the difference between the menus is roughly 25Mb per user. This means for every two users on the Java menu, we could have three users on the Tcl menu.

Let us take a crude example of a sun server with 16Gb RAM; 350 Tcl users or 230 Java users (Not these figures are theoretical and using 100% of the memory). Thus I would make another sweeping estimate and for a stable system, divide these totals in half. Giving us a final total of 175 Tcl users or 115 Java users: that is 60 extra users on the Tcl menu!

So what is the conclusion? It depends on your setup, priorities and of course budget. Does a slightly more stylish menu warrant the memory overhead? In most cases I would assume the reason why Sunrays are being used in the first place, is to cut costs and deploy in a large scale environment, so unfortunately attractiveness will be an afterthought.

With functionality, efficiency and capacity being paramount; I decided on Tcl.

…for the moment…

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SunRay Update 6

“You never get a second chance to make a first impression.”

The core of the new sunray release was to ensure the sunray server software were setup in an optimal manner. Moving onto new and powerful servers, with a fresh install configured for performance.
However the key to accessing this functionality is the menu screen. To focus to the latter stages of the project the menu has undergone several stages of development using the Waterfall model for software life cycle.

Obviously this element to the project is where the users will get their first impressions, deciding on their likes and dislikes of the system as a whole, so getting the front end as user friendly as possible was key to the design and planning. Research was conducted on several possibilities and in the end we narrowed it down to two potential languages; Tcl and Java. The menu which had previously been made and used was written in Tcl and with its two buttons, chiefly acted as a floodgate for the sunrays – if the menu were not there; the sunray devices simply cycle continuously waiting for a server or else connect to a terminal server utilising resources when there is no demand. But now we needed more functionality and implemented in such a way that actually reduces the hassle of logging in, rather than adding another stage to the process.


The prototype for the system seemed to perform effectively, although by no means complete it had the core functionality and no major issues arose. The most negative feedback was due to the slightly overwhelming blue and clumsy buttons.

Ideally we needed a simple login menu, without too much information, yet intuitive enough to understand immediately without guidance. Our original two button interface had roughly a dozen variations for connecting to different servers which made updates laborious. There must be facility to input a username and password, select screen resolution and be resistant to any tampering.

Given the adaptability of Java, it seemed like a logical move to create a visually superior model. Using java swing we created a slick and fully functional menu.

The JFrame itself is expandable, allowing for additional options to be displayed without requiring a new window.


However when analysing the memory overhead, the use of a Java menu utilised substantially more memory than the Tcl menu. This overhead unfortunately meant it would not be a feasible option when compared to the lower requirements of Tcl.
Thus we revert back the previous possibility of a Tcl menu, though there were several changes which needed to be made. The visual aspects of the menu were simplified and colours were swapped for a more sensible greyscale.
With the new buttons, a dropdown menu was created to reduce the requirement for extra shell scripts. Now the majority of the menu and its functions will run directly from the original Tcl script.


Finally, the only issue left with the menu was the slightly blocky fonts used. We had originally overcome this problem by using images rather than text labels, but this isn’t the ideal solution as changing text becomes an annoyance. Instead by downloading the most recent version of Tcl (and wish), smooth rounded fonts are available and the final result – I think – looks stylish and more importantly works efficiently and effectively.

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SunRay Update 5

With the new release of the menu, the requirement specification needed functionality in place which would allow administration of the sunray users from the web management interface.

We have several types of user each requiring a custom Windows kiosk session.
Previously to specify where a particular sunray unit should connect, we were setting the individual firmware on each device.
This allowed us to direct units towards specific servers, however since we have consolidated our sunray server cluster, all the units will be connecting to our sunray cluster regardless of which Windows session is required.

Now the administrator only needs to enter a predefined string into the “Other Information” section in the web interface.

The shell script will read what has been entered into this field before loading the Tcl menu

#!/bin/sh
TOKENRIGHTS=`/opt/SUNWut/sbin/utuser -o|grep $SUN_SUNRAY_TOKEN|cut -d ',' -f 5`
export TOKENRIGHTS
/usr/openwin/bin/xsetroot -solid "#36566c"
/usr/local/solaris-sparc/bin/wish8.5 </opt/SUNWutMenu/menu.tcl

“&lt” is a less than symbol (pointing right) “>”.

This value can then easily be validated and matched against a rule set to ensure the user is sent to the right place given their kiosk access within the Tcl script. We import the environment variable and then perform any logical operations on the value we desire.

set SECURE $env(TOKENRIGHTS)
if {$SECURE=="student"} {set HOST $IPAddress1
} elseif {$SECURE=="staff"} {set HOST $IPAddress2
} else {set HOST $IPAddress3}
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SunRay Update 4

The inevitable question is how.

Essentially creating two text fields is no huge task, however when one considers all the minor trends and habits users acquire, several considerations needed to be made – these will be considered later.

I will cover several aspects of the menu code; this post is written with the intension to be used as a reference guide rather than a walkthrough for an implementation. You are welcome to use any of the code and I will be happy to provide any assistance or explain further although using the code (or my advice) is at your own risk.

The sunray menu at the Solaris side is basically comprised of two main parts; a Tcl menu and a shell script.

The menu itself is created using Tcl.

In order to run the windows connector, we have a procedure which imports the entered username, password, kiosk username and applicable host IP address.

proc log {username password KIOUSER HOST} {set EN1 [string trim $username]; set EN2 $password; \
        .sub.top.entry delete 0 end; .sub.top.entry2 delete 0 end; focus .sub.top.entry; \
        exec echo $EN2 | /opt/SUNWuttsc/bin/uttsc \
        -k en_GB -l en_GB -m -b -O -r sound:high \
        -r disk:USB=/tmp/SUNWut/mnt/$KIOUSER \
        -u $EN1 -i $HOST }

button .sub.top.kiosk -text "Login" -font defaultFont -command { log $username $password $KIOUSER $HOST}

This procedure also clears both of the text fields and sets the focus to the entry text box. This clearing is done before the windows connector to ensure regardless of whatever event, the details are not saved and will always be removed.

With a single frame positioned in the middle of the screen, the focus of textboxes required users to move their mouse over the frame. To resolve this issue I created a frame within another frame on the page. The background frame being set to the maximum screen size and the menu frame will auto size itself depending on the internal widgets contained.

set width [expr {([winfo screenwidth .]-[winfo width .])+1}]
set height [expr {([winfo screenheight .]-[winfo height .])+1}]

frame .sub -background black -width $width -height $height
frame .sub.top -background grey -borderwidth $BORDER_WIDTH -relief raised

This does present another issue, as the menu frame is dynamically generated, how would one centralise it on the screen? Essentially there are two potential resolutions, you could hard-code the dimensions (not ideal if the menu ever changes) or calculate the size after it has been rendered.

I decided to proceed with the latter option and in fact what my script does is place the whole menu frame outside the viewable screen, measure the dimensions and then with these figures reposition it exactly in the middle of the screen.

This image conveys the calculations which are essential to dynamically centralise the menu.

In pseudo code:
The menu frame is created (actually outside of the BIX by BIY boundary, but represented inside for simplicity) as GrX by GrY = Grey position.
The centre of the screen: BY/2 by BX/2 = Dark Blue Grid.
Moving the menu frame GrX by GrY + BY/2 by BX/2 = Light Blue position.
Calculate the value half length of menu frame LbX/2 by LbY/2 = GX by GY.
Move menu to the centre of the screen LbY – GY by LbX – GX = RY by RX.

And now no matter how big or small our menu frame is made, it will always be set in the middle if the screen.

set c [winfo width .menuframe]
set d [winfo height . menuframe]
set e [expr {($a)-(($c)/2)}]
set f [expr {($b)-(($d)/2)}]
place .menuframe -x $e -y $f

In an aim to be openly usable, we make every effort to make our systems viable to people who might be visually impaired. Luckily, Sun really made this easy with the sunray system, allowing us to set a sunray to a particular resolution.
The command in the sunray software is called using utxconfig – in the following format: /opt/SUNWut/bin/utxconfig -t $TOKEN -r “1024×768”.
We decided three main resolutions would provide our users with a good scope: 1280×1024, 1024×768. 800×600.

The user is able to change their resolution from the same menu screen and no extra script is required. Based on a dropdown menu, the user can choose their desired option, then the sunray will reboot itself and apply the changes.

menubutton .menuframe.resol -text "Preferences" -font defaultFont -relief raised \
        -menu . menuframe.resol.options
menubutton .menuframe.resol -text "Preferences" -font defaultFont -relief raised \
        -menu . menuframe.resol.options

menu . menuframe.resol.options
        . menuframe.resol.options add command -label "High 1280x1024" -command \
                { exec /opt/SUNWut/bin/utxconfig -t $TOKEN -r "auto" >/dev/null 2>&1 ; exit }
        . menuframe.resol.options add command -label "Medium 1024x768" -command \
                { exec /opt/SUNWut/bin/utxconfig -t $TOKEN -r "1024x768" >/dev/null 2>&1 ; exit }
        . menuframe.resol.options add command -label "Low 800x600" -command \
                { exec /opt/SUNWut/bin/utxconfig -t $TOKEN -r "800x600" >/dev/null 2>&1 ; exit }

Where &gt should display “>” and &amp should show “&1”. >/dev/null 2>&1

Our menus widgets are placed in a grid format within the menu frame (which is within the screen frame).

Finally to allow the ‘return’ or ‘enter’ key can be used to login, it needs to be bound to a procedure – much like the login button. In this case the return key can be used to login when and only when the focus is on the password field.

bind .menuframe.entry2  { log $username $password $KIOUSER $HOST }

Please note, I have trimmed, rearranged and edited some of the working code to simplify it for this post. You should be able to copy chunks of code, but please make sure you understand what it is doing, else you will likely fall prey to a simple syntax error.

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Back to the Classroom

Well it’s about time I wrote another post .

I was recently out and about in a very wet Manchester at a Janet Training course

http://www.ja.net/services/training/courses.html

The Course was a Introduction to DNS course

A brief introduction about the course from Janet was, “that every time someone uses JANET or the commercial Internet they make use of DNS. DNS handles the mapping between the users’ requests and internet addresses. The main objective of this course is to provide a basic understanding of DNS principles and theory. Some of the key technical implementations will be reviewed in the context of a Windows 2003 DNS interface but the priority of the course is to provide delegates with a sound background in DNS principles.”

Apart from the course what I found particulary interesting was the pre and post course web site EdLab:

Edlab is a Online Collaboration support and learning website that registered delegates get access to along with the new pre-course support area.
It gives you details of what to expect from the day which I found useful , along with pre and post pre-course resources , also it gives you information such as ‘Meet the Trainer’ a section which provides you with a introduction to the course trainer (and a picture), which came in particularly useful for such a small group of delegates as I was in!

It also has a section on the exercises you do in the course and the course materials so you can go over the course again in you own time

Edlab also provides you with a discussion area so you can talk to other delegates after the course and get their views.

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Sunray Update 3

Each PC (including TFT monitor) consumes 105 W.
Each sunray (including TFT monitor) consumes 41 W.
Each sunray server consumes 242 W.

Thus on a bases of 500 sunray DTU’s = 20500 W.
Compared to 500 individual PC’s using a total of 52500 W.

This is a difference of 32000 W; 32kW.

The average workstation is used 37 hours a week, 148 hours a month.

Per month:
PC total consumption – 7770 kW
Sunray total consumption – 3500 kW
Difference – 4270 kW

That is saving 1.84 tonnes of carbon emissions and roughly £500 of electricity saved every month, resulting in a total of 22 tonnes carbon emissions and £6000 a year in electricity savings alone!

Sound impressive? Well it doesn’t stop there. By design every single sunray DTU will automatically shutdown to a standby state in 10 minutes, in this state they run at less than 1W.

Most PC’s will by default display a screensaver on the monitor and continue to run all the normal computer operations (Cpu, fans etc) consuming 85 Watts. This period of inactiveness (we will estimate) is 131 hours a week and roughly 600 hours a month coming to a total of 25kW/h and £2000 a month; 300kW and £24000 a year completely wasted! I should clarify this is on the assumption that every PC in our sample is left on.

Thus with a sunray setup compared to individual PC’s supplying 500 users, regarding electricity alone you can expect a saving between £6000 and £30000 depending on the number of PC’s turned off when not in use.

Therefore combining these figures, on our estimated daily and nightly rate, let us assume 50% of your PC’s are turned off during non-work hours, you’ll save roughly £18000 a year and sleep better at night knowing you help to make the world a greener place.

With this extra saving, why not consider reinvesting your savings in some solar panels, cutting your electricity bills to zero!

So what does this mean for your organisation? Whether you are aiming to achieve a environmentally friendly status, clear you conscience, capitalise on eco-marketing or just save a pile of cash, come away from this post with two gems of advice: Sunrays and thin clients are becoming even more cost effective in our current economy and most importantly, whoever you are, TURN YOUR PC’s OFF!

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Sunray Update 2

What is new?

• A new streamlined menu; users can now input username and password on initial screen.

• Improved performance of system, meaning everything should run smoother.

• Sessions will now be managed more efficiently. If there is ever a network problem or power cut all sunray users should get their session back and be able to continue without any major disruption.

• Due to the session management, users can effectively “hot desk”, allowing you to access your live session from any sunray!

• The servers have been installed and configured to enhance server and session stability.

• Faster servers have been purchased to increase speed and reliability.

• Fixed the issue where typed characters were delayed slightly before being displayed on the screen.

• Fixed the issue where certain keys were not working properly (eg. print screen button).

What is happening?

Once you enter your credentials and click the login button (or press enter), the system automatically finds one of our servers where you can begin your work.

This choice is not random; instead it is based on the available resources on each server (called “Windows Terminal Servers” – or “TS”) assuming you don’t already have an active session.

If you were already logged in on a different sunray or SRD (Sunray Remote Desktop), you will retrieve all your work you previously had open!

All the processing is done by a controlled, optimised and managed server; providing enhanced speed, security and reliability. This is massively more efficient than the sporadic utilisation of individual PC resources.

What does it look like?

.
.
Why use a Sunray?

• They are silent and produce little heat.

• The sunray takes up very little room on your desk.

• There is almost no way you can accidently damage the sunray (within reason!).

• If your sunray is stolen, your data is safe as there is no data stored locally on the sunray.

• Your sunray will never need to be formatted and reinstalled like a PC.

• If there is a hardware failure with the sunray, you won’t lose any work.

• If there is a hardware failure with the sunray, it can easily be replaced and won’t need you to change any settings.

• There is almost no way you can damage the software applications you use (applications, not the saved files).

• You cannot accidently install programs such as spyware without your knowledge.

• The system saves energy for the university, is ‘greener’ and reduces our carbon footprint – better for the planet.

Tips and Tricks

You can easily see which server you are working on by looking at the symbol on your desktop which normally says “My Computer”, but will now say “ on TS#” (where the # is a number).

If you are experiencing strange behaviour from your sunray (keyboard or mouse issues) try pressing Ctrl – Moon (top right key). This is power cycle your sunray DTU without affecting your current session.

If you are visually impaired (or just like big icons) you can set your DTU to remember your settings. All you need to do is make sure the login menu is being displayed (log out if you are logged in) and select “Preferences” – then choose whichever option you require. High – small icons and clearer resolution; Medium – medium icons and medium resolution; Low – large icons and lower resolution. Once you have made your choice the menu will automatically power cycle itself and change your desired setting. Now log in as per normal.

You will be able to “hot-desk” – allowing for you to log in at one workstation, go elsewhere and log in somewhere else with exactly the same screen as you had before.

What is next?

We are still working closely with Sun Microsystems to:

Develop this system for improved media viewing performance
Enhance the USB functionality.
Advance functionality.
Improve stability.

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SunRay Update 1

We are pleased to announce the deployment of our new and improved sunray service.
As the first anniversary of our original sunray installation approaches, I have recently been investigating, developing, improving and fixing our current setup.

With 360 sunray devices connected (and used daily) and another 90 ready to be installed, Sunrays are a common sight at Edge Hill University.

Generalised Strucuture

Our sunray infrastructure is based on;
4 x Solaris Sparc – Sun T1000 (8 Core Cpu, 16Gb RAM),
Installed with Solaris and sunray server software (in a failover group).

3 x VM Windows Server 2003 (1 Cpu, 1024 Mb RAM),
Running 2x Load Balancer; 1 primary and 2 secondary.

8 x Windows Server 2003 – Sun Fire x4100 M2 (Dual Core Cpu, 4Gb RAM).
Setup as Windows Terminal Servers.

And a controlled growth planned already!

Previous to this release we were experiencing issues where users were being assigned a new session when they had logged in after being disconnected. This is a real overhead as not only does this put extra strain on our servers, but files may be left open and be locked for future editing. This also has a knock-on effect to support and our helpdesk were having to support unnecessary issues. However with a packaged binary, the method which the sunray servers communicate with 2x is vastly improved.

The sunray system now allows true confidence in handling sessions, allowing for hot-desking and session management over the whole campus.
So, the obvious question is how. Essentially the issue with session handling is the credentials which are passed from the sunray server to the 2x load balancer. Previously the only detail which the system could use to match a session was the pseudo token id. With the newly designed menu, the username itself is passed across to the load balancer to search for an active session.

After the required development planning was conducted, it was eventually decided the menus would be created using tcl script. This language is not difficult to pick up by anyone with some programming knowledge and there are plenty of resources available on the net. Other options were available – and will be mentioned in a later post – but remaining with tcl proved to be the most viable choice.

Our new menu has moved away from two simple buttons to including a full login window. Originally our users need to select the login button before being presented with a further login which allowed the entry of their credentials.

But now our menu allows users to enter their details immediately without the extra delay.

As with all developed systems, this has been designed with the users specifically in mind. We have aimed to minimise any issues which may annoy or frustrate users.

I will go into the design requirements, specifications, choices and coding in a later post.

The important factor about this release is the back-end of the whole system, the menu is merely a conduit to enable the functionality to work as we would like.
Fixing the majority of issues raised by users and ourselves, the new system really should demonstrate PC’s are a thing of the past!

Sunrays have so many bonuses over a PC, but as with anything else in this world, there is rarely a ‘one-size-fits-all’ answer. Sunrays offer a fantastic workstation; fast processing, efficient, power saving, support saving, quiet, cool and flexible. However before investing in such a system, you should ensure your infrastructure will facilitate the transformation of business rules; it is often a case of “yes you can’t do that anymore – but you don’t need to either”.

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Elonex Update

A few people have shown repeated interest in the Elonex laptops I blogged about earlier on in the year. I’m dissapointed to say that today I cancelled my order and requested a refund. Despite placing a deposit on two Elonex laptops at the start of March and paying for the laptops on 11th July, Elonex are still unable to deliver the laptops almost 2 months after I paid for them and almost 6 months after I put the deposit down. I’ve been quite dissapointed by Elonex and every email promise of delivery was broken. I’m not sure where this leaves the ‘vision of the ONE project by Elonex is for every child in the UK to have their own laptop’, it seems that there might be many children without a laptop when school starts later on this week. Interestingly I’ve noticed that a UK Mobile Phone retailer is now supplying Elonex laptops as part of one of it’s broadband packages.

Posted in Gadgets, General | Tagged | 3 Comments