links for 2006-03-31

Transcending Boundaries with Federated Identity

If you’re an ‘information technology leader’ then you’re probably already subscribed to Sun’s Inner Circle newsletter, so you’ve probably already read ‘Transcending Boundaries with Federated Identity‘ – an interview with my fellow architect, Rajeev Angal.

Rajeev presents a thorough grounding in federated identity – what it is, why you should care and how to get started. If you’re trying to get a grip on what federation is all about, this is a great place to start.

By the way, there seems to be a glitch with the feedback form at the bottom of the article. If you’d like to comment, then please do so here and I’ll ensure it gets back to Rajeev and the Inner Circle crew.

links for 2006-03-29

links for 2006-03-28

Unabashed Nostalgia and Technical Analysis

I’ve worked for a few companies over the years (go to my LinkedIn profile for the full gory details) – one of the most fun jobs was with Synergy Real-time Systems (don’t bother looking for it – it’s long gone) in London.

The office was in the square mile of the City of London (the financial district), a stone’s throw from the Bank of England. Our core product (ok – our only product 🙂 ) was RITA – Real-time Interactive Technical Analysis. Technical Analysis is the practice of making investment decisions based on charts of stock prices. As well as the basic price, technical analysts look at other indicators such as moving averages and more complex analyses such as relative strength index and Bollinger bands.

Anyway. I was playing with Google Desktop the other night and discovered its timeline. If you value your time, stay away! I spent a happy couple of hours googling through documents from 10 years ago. One that I found was a Word document I had emailed to my home account as a test. The document contained a RITA chart as an OCX control (OCX became ActiveX):

The chart shows the movement of the Benetton Group’s (BNG) stock on the Milan (.MI) market for the last 4 months in 1996. The top chart is a bar chart – each red vertical line shows the high (top of the line), low (bottom of the line), open (tick on the left) and close (tick on the right) for a given time period – in this case, each day. Superimposed on the bar chart are two moving averages and a trend line. The middle chart is percentage on-balance-volume (OBV), an indicator of momentum. The bottom chart shows volume bars (green) and a moving average of the volume. Don’t ask me whether the chart indicates a buy or a sell – I never could figure it out!

What I did love was programming graphics. It’s very rewarding working on a system where the feedback is so immediate and visual. And working in a small company of less than 10 people – hi Ezra, Dilnaz, Mike, Matt, Chris, John, Dom, Kevin and Mike (Jenko!) (I’m sure I must have missed somebody!). And being able to go to the pick of the City’s pubs after work. Ah – happy days!

Liberty User-Centric Identity Whitepaper and Webcast

There’s a lot of buzz around ‘user-centric identity’ right now – the notion of involving users in the management of their personal information and its use, rather than leaving it to some enterprise or other organization. The folks at the Liberty Alliance have written a whitepaper entitled ‘Personal Identity‘ that shows how Liberty’s Identity Federation Framework (ID-FF) and its successor SAML 2.0 can be used to implement user-centric identity – for example, a user providing their own identity services via a Liberty-enabled device such as a cellphone. It’s a good read – it starts from the basics, so you should be able to follow it even if you’re new to Liberty and SAML.

On the same topic, John Kemp of Nokia and my esteemed colleague Hubert Le Van Gong will be presenting a webcast on April 12 2006 at 8am Pacific. PLEASE NOTE: Registration is required and limited to the first 100 respondents! The last webcast on the Liberty People Service ‘sold out’ very quickly, so get in there straight away if you’re interested. If you’re too late, don’t despair – the webcast will be available in archive form after the event. I’ll update this entry with the URL once it’s online.

To register for the webcast, follow these steps.

  1. Go to
  2. Under the heading Attend a Meeting, click Register
  3. Search for centric
  4. Select User Centric Identity: Success Today and click on the Register Button. (Don’t bother clicking on the link – it doesn’t lead anywhere useful!)
  5. Fill out the required information and click Register Now at the bottom of the page.

Please email Tricia DeHart of the Liberty Alliance Project with any questions.

Reworked script to remount USB drives on SuSE 10.0

I realised that I could generalize yesterday’s ‘remount’ script to remount all subfs filesystems. Here is the new version:

#! /bin/sh
# Look for any filesystems mounted as subfs, unmount them,
# then remount them manually
mount -t subfs \
| awk '{print "echo Remounting " $1 " on " $3 "; umount " $1 " && mount " $1 " " $3}' \
| sh

I’m sure you could use Perl for this instead of Awk, but my skillz are little more old skool

I need hardly add that these shell scripts are totally unwarranted. Use them at your own risk. I or Sun cannot be held responsible if, after running either of these scripts, you lose data, money or friends.

USB Drives in JDS / SuSE 10.0

UPDATE: See the following entry for an updated script and, perhaps more importantly, a disclaimer for these scripts.

As you can probably figure out from my links, I recently moved my laptop from JDS to SuSE 10.0. JDS worked great, but the kernel is a bit long in the tooth now, and doesn’t recognize the SpeedStep function in my Tecra M2. Anyway – one thing I’d noticed in both JDS and SuSe 10.0 is that USB 2.0 drives mount ‘automagically’ when you plug them in via submount. I’m not sure how well this works with other file systems, but with Reiser it’s a nightmare. What seems to happen is that, when there are no files open, the drive is quietly unmounted, just in case you’re going to pull the cable out. When you next try to access the drive (e.g. ls /media/usbdisk) the drive is quietly remounted. With reiserfs, this takes a while – over 10 seconds for my WD 250MB drive – which is very frustrating.

There are various solution posted, which require some low-level tinkering, and are specific to the exact version of JDS/SuSE you’re using, but I discovered one easy way to fix the problem that doesn’t mess with any configuration… I created an ‘rmount’ script in my bin directory:

#! /bin/sh
# You may need to run this as root!
# You could pass these in as parameters, I guess, but then
# you'd be just as well running the umount and mount
# commands manually :-)
echo -n "Before: "
mount | grep $DEVICE
echo "Remounting $DEVICE on $MOUNTPOINT as $FSTYPE"
echo -n "After:  "
mount | grep $DEVICE

Just change the device, mountpoint etc to match your configuration. Now, when you connect your drive just close the Konqueror/Nautilus window that pops up and run the rmount command. Likely you’ll need to run the script as root to be able to do the mounting/unmounting. Here’s the output on my system:

linux:~> sudo rmount
Before: /dev/sda1 on /media/usbdisk type subfs (rw,nosuid,nodev,fs=reiserfs)
Remounting /dev/sda1 on /media/usbdisk
After:  /dev/sda1 on /media/usbdisk type reiserfs (rw)

Job’s a good ‘un! Just remember to unmount the drive before you disconnect it now! Oh – and, apparently, submount/subfs is gone in SuSE 10.1, so we’ll just have to see how well things work in the future…