Apple Store Invoice Missing Labels

The AirPort Express arrived the day after ordering it though. :-)

File Management

I need to access my personal files in different locations such as home, work office or when traveling. I wish to be able to move between a number of trusted computers, rather than being tied to a specific laptop, as I like to cycle to and from work. I also don't want the hassle of running my own server at home (have done this in the past).

So my first step in solving this is to store all my files in a Distributed Version Control System. I get all the benefits of a common centralised VCS such as version history and version management between multiple machines, as well as being able to work normally when I don't have an internet connection (e.g. travelling). I have chosen Git, although Mercurial would probably be a fine choice to.

The second step is having a location for a master repository that is accessible over the internet. I could have purchased a hosted linux virtual machine, but I didn't want to deal with setting it up, security, software upgrades, etc. Git can synchronise repositories located at different points on the same file system, so I thought I would try a locally mounted, encrypted virtual file system over Amazon S3. I chose JungleDisk for this purpose.

As it is only me using these Git repositories, I only have one machine writing to the master at any one time, so I don't have to worry about concurrency issues. Secondly, whenever I clone a repository from the master, I use the --no-hardlinks option, although I am not sure if that is necessary.

In principle the ideas have worked out pretty well. I have run into some issues though. From minor to major:

• S3 has been unavailable on two occasions, when I have tried to access it in the last three months.


• Sometimes I have had errors pulling (synchronising) from the master. Recreating the local repository by cloning it again from the master has solved these issues. This may also be similar to the next one.


• I have had a case where I don't get any errors pulling from the master, but I don't get the latest commits pushed from another machine either. This one has been a real pain. In the process of getting everything back to a stable state, I updated to Git 1.6.0, JungleDisk 2.10a, deleted my local JungleDisk caches and reduced the cache size down to the minimum (I would have liked to turn caching off altogether). I suspect the JungleDisk caching was the issue, but that is only a guess. Will see how things go over the next few weeks.

I now don't need backups from a file deletion point of view, as the VCS takes care of that (I am not using any of the Git feature to modify history). I also keep a subset of the machines synchronised on a daily basis, so I don't need backups from a hardware failure/lost/stolen perspective either.

Introduction To Scala Training Course

Workingmouse is running an Introduction To Scala training course from Tuesday 2nd September to Thursday 4th September. The course will be run in an interactive, "hands-on" format, with a small number of people, ideally between 4 and 8.

The course covers topics including:

• Scala syntax


• A brief introduction to the essence of Functional Programming


• Algebraic Data Types and Pattern Matching


• Closures and Higher-Order Functions


• Integration with Java


• Intermediate Functional Programming topics (if time permits)

Scoodi and Me on TV

Well last week I made my TV debut, not that being on TV is something I aspire to. The subject was Scoodi and the show was Brisbane Extra.



I thought I would clarify some of the things that were said though.

First of all, I am not the brains behind Scoodi. That honour would go to Pete, who engaged us to develop the site. During that process I decided that I liked the purpose of Scoodi and thought it had potential, so became more involved.

The filming/interviewing felt pretty awkward and contrived to me. The TV crew were good guys who were trying to make things relaxed, but I wouldn't normally say things like: "You've got council pickup, garage sales and now you've got Scoodi" and "it beats a trip to the tip". Those lines seemed a pretty corny at the time.

Overall though, I was pleasantly surprised at how well the segment turned out. I was even more surprised at the amount of people that visited the site and signed up. I really hope they find it useful.

Maths Symbols in NeoOffice

I wanted to have a character (representing the integers) in a NeoOffice document on Mac OS X 10.4. I couldn't find an installed font containing the character and according to Wikipedia I need a Blackboard Bold typeface style. After a few google searches I found a jsMath font that seemed to work fine.

GMail Down

Both personal and work GMail is down.

Paper Airplanes

Alex's paper airplanes and Joseph Palmer's Paper Airplanes have good paper airplane designs. Fun for the whole family!

Optus Mobile Outage

Optus mobile users were not happy here in Brisbane when they couldn't use their phones yesterday due to a software issue. Story coverage here and here.

Presentation: Paul Cormier from Red Hat at QUT

Yesterday, Paul Cormier, Executive Vice President and President, Products and Technologies, Red Hat gave a talk titled "Red Hat and the Open Source Software Business: from boxed software to a half billion dollar server company" at QUT.

Paul made two points that stand out in my mind:

1. The primary differentiator of an open source project software project (compared to closed source) is in the ability to build a community of people around the project.


2. He sees Red Hat as taking open source work and packaging it in a way that is palatable from an enterprise perspective. Specifically, providing stability and backward compatibility for a 'long-enough' period of time.

If I consider Scala in this light, it is currently doing well on the first point, but not so well on the second. Given that the primary users of Java are enterprises, this is important if mainstream penetration is an objective.

Having said that, I think there is a time when the cost of backwards compatibility outweighs the benefits and my threshold seems to be a fair bit lower than that of the average enterprise. In this case, I think enterprises would do well to step back and consider the real costs in doing a software project in Java (or Ruby/Groovy for that matter) and seriously consider the potential benefits from more advanced programming languages.

Introduction To Computational Logic

From Saarland University: Introduction To Computational Logic.

Includes lecture notes and references to literature.

Introduction To Logic

Carnegie-Mellon Open Learning Initiative: Logic and Proofs course