basically tech

115 London Stock Exchange abandoning Windows

Friday 3rd July, 2009

The London Stock Exchange is abandoning it's Windows-based TradElect trading system. The system crashed in September 2008.

TradElect runs on HP ProLiant servers running, in turn, Windows Server 2003. The TradElect software itself is a custom blend of C# and .NET programs, which was created by Microsoft and Accenture, the global consulting firm. On the back-end, it relied on Microsoft SQL Server 2000. Its goal was to maintain sub-ten millisecond response times, real-time system speeds, for stock trades.

It never, ever came close to achieving these performance goals. Worse still, the LSE's competition, such as its main rival Chi-X with its MarketPrizm trading platform software, was able to deliver that level of performance and in general it was running rings about TradElect. Three guesses what MarketPrizm runs on and the first two don't count. The answer is Linux.

I'm sure someone got some nice lunches out of it while it lasted.


114 Debian lenny MailScanner woes

Friday 3rd April, 2009

I fixed this after a week or so, but I forget how I did it. :-( I don't use MailScanner anymore. It's a fine product, but I find it to be overkill.
Rob. April 2015.

I ran a system upgrade (from etch to lenny) on one of my Debian servers today. There seem to be lots of people who have their own ideas about how to go about this, which is fair enough, there's more than one way to climb the mountain. In fact I deviated (very) slightly from the steps kindly provided in the official upgrade instructions.

I double-checked the official issues to be aware of for lenny. Nothing about MailScanner!

113 The Tech Lab: Bruce Schneier

Saturday 21st March, 2009

A cautionary viewpoint concerning the unintended consequences of the current Information Age from Bruce Schneier. I think it's worth reading.

Data is the pollution of the information age. It's a natural by-product of every computer-mediated interaction. It stays around forever, unless it's disposed of. It is valuable when reused, but it must be done carefully. Otherwise, its after-effects are toxic.
Cardinal Richelieu famously said: "If one would give me six lines written by the hand of the most honest man, I would find something in them to have him hanged." When all your words and actions can be saved for later examination, different rules have to apply.


112 Linux tips every geek should know

Monday 2nd March, 2009

This is a great collection of random Linux tips (57 in all). They were originally published in Linux Format magazine. The various tips are categorised into three levels of difficulty, easy, intermediate, and expert. Well worth a read.


111 sed and iostat

Saturday 22nd November, 2008

This tip is specifically for the version of sed which came with Solaris. GNU sed has options which make solving this problem much easier.
Rob. April 2015.

I'm sure many Solaris admins will have come across this problem before. You have a SAN-attached host with dozens, maybe even hundreds of visible LUNs. Each LUN has a highly improbable and unwieldy name, as some of these SAN-attached devices do, and you need the iostat data for that LUN.

grep is no help, because you also want the four lines of data beneath the 'disk' name.

Well, you could just run iostat and painstakingly trawl through hundreds of lines of data, searching for the information you need. Or you could use the goodness of sed to find your LUN, and the four lines of data beneath it ...

$ iostat -En | sed -n '/c4t60060480000290101035533030433430d0/{p;n;p;n;p;n;p;n;p;}'

c4t60060480000290101035533030433430d0 Soft Errors: 0 Hard Errors: 1223 Transport Errors: 1170
Vendor: EMC      Product: SYMMETRIX        Revision: 5771 Serial No:
Size: 54.41GB <54408314880 bytes>
Media Error: 0 Device Not Ready: 0 No Device: 75 Recoverable: 0
Illegal Request: 0 Predictive Failure Analysis: 0

And that is a genuine LUN id!


110 Colour-coded battery charge level and status in your bash prompt

Thursday 11th September, 2008

I still use a version of this script. The Linux kernel has changed somewhat so the script as it is below probably won't work. (Instead of /proc/acpi/battery/, direct the script towards /sys/class/power_supply/. And do make some other small changes.) I should update this.
Rob. April 2015.

I recently purchased a laptop, and having installed a proper OS, I found myself a little disappointed with the default battery meter provided by GNOME. Unless you mouse over the icon on the panel, it doesn't display exactly what charge level it is at. I am aware of the other options such as conky, gkrellm, screenlets, etc, but being the lazy sort, I consider it a long way to move your eyes! Since I'm the type who always has several terminals open, I thought it would be handy to display the charge level and status of the laptop battery in my shell prompt.

109 find is an amazing tool

Friday 11th July, 2008

I found a new article about the remarkable command-line interface utility 'find' today. It's a good article, but the best I've found so far is Daniel Miessler's excellent tutorial on the subject, which also incorporates some xargs goodness, something which the former sadly neglects.


108 ZFS and Linux?

Sunday 18th May, 2008

This is concerning a cryptic entry from the blog of Jeff Bonwick. The two guys in the photos (follow the link) are Linus Torvalds and Jeff Bonwick. Jeff Bonwick is maybe not quite as well known as Linus Torvalds. He's the CTO of Storage Technologies at Sun Microsystems, he's also the ZFS development team leader, and his blog pretty much focuses on ZFS.

So, what's this about? Aren't there supposed to be licensing issues with Linux and ZFS? All I can assume when Jeff Bonwick says:

All I can say for the moment is... stay tuned."
is that there are "talks about talks". There are certainly interesting possibilities, ZFS is impressive stuff.


107 Three awk resources (and one old sed)

Wednesday 14th May, 2008

I use awk (or rather gawk and nawk) a lot, and I was intrigued to find two resources on the internet very recently. This sort of information used to be hard to come by, so it was good to find it.

The first (and IMO the best) resource I found was an awk tutorial called Getting started with awk.

The second was an Awk, Nawk and Gawk cheat sheet.

Add to that my old favourite Handy one-liners for awk, which seems to have taken it's inspiration from the venerable and much-queried Handy one-liners for sed, and you have the four resources hinted at in the title. I hope it proves useful.


105 Safari imposition

Thursday 27th March, 2008

There's been a little flurry of news regarding Apple's "Safari" web browser.

The first thing which caught my attention recently was Apple's bundling of Safari by default into iTunes and Quicktime updates on Windows PCs. So unless you're on the ball (but aren't all Internet users on the ball?) and deselect the "Safari" checkbox, you get Safari downloaded and installed on your Windows PC. Well of course you wanted it!

In this update, Apple claims that "Safari for Windows is the fastest and easiest-to-use web browser for the PC", a claim which is countered by many sources. I guess these things are perceptual to some people, rather than quantitative!

This has now been followed up with a fascinating paradox in the EULA which comes with Safari for Windows, which states that you are permitted to install said software (unwittingly downloaded or not) onto no more than "a single Apple-labeled computer at a time." Which means that if you're installing Safari for Windows (which you may have been tricked into downloading and installing in the first place) onto a Windows PC, you're violating the terms of the license.

Added March 28, 2008

Slashdot has a couple of articles related to this, one discussing the points above as well mentioning that Safari seems to be suffering some security vulnerabilities. The second article follows up on the vulnerability theme; at the CanSecWest hacking contest, a MacBook Air was compromised within two minutes due to a Safari-based vulnerability.