Another Weekend in Frankfurt

More than two years had passed since my last visit to Frankfurt so this past weekend I hopped on a train and went to see M. There isn’t much to say about the weekend other than that is was awesome. Thanks, M.

Below are some pictures; I particularly love the first one. Photoshop Express has done a really nice job of bringing out the best of it.

Ankunft in Frankfurt (1)

The Frankfurt Book Fair:

Buchmesse (1)

Buchmesse (2)

Messehalle Längst Schwarz-Weiß

Skyline at night in the rain:

Skyline im Regen bei Nacht (2)

[26-Oct-2014 Update] Here are two images missing from the original post.

I took these with one of M’s camera: a Sony Alpha 100. Unlike like my Alpha 58, the 100 is a classic DSLR and does not yet have Sony’s Single-Lens Translucent (SLT) technology. Since the 58 was the first real camera I bought, I wasn’t accustomed to the way the 100 works, and I must say, I really missed the electronic viewfinder. It’s so convenient to see the final image after you’ve made the shot without having to remove the camera from your eye and check the screen all the time.



Looking back at Year Five at Personal Nexus

Today is the fifth anniversary of the day I started this blog. In the past, I’ve used this occasion to review what I had posted, how many people had visited my blog et cetera.


Going forward, I don’t think I’ll do that anymore. What I will do though, is post a bit more regularly. I have a few things lined up already: the conclusion of the .NET Gadgeteer story and some more photography related posts. And if all goes well, I’ll be able to travel a bit for work and bring back some pictures and stories in the coming months.

Notes from Delphi Days (Delphi Tage) 2014

After doing new development mostly in C# for the past couple of years, I’ll be creating some major additions to a (legacy) Delphi application soon. I already got Delphi XE7, so I figured what better way to catch up than attending the Delphi Tage which happened to be fairly close again (I attended once before in 2011, when they were held in Cologne).

In the end, I didn’t learn that much about Delphi (except for Marco Cantu’s keynote). Instead, of the sessions offered, the ones that interested me most, were actually not about Delphi at all.


Bonn (2)Most of the applications I work on are heavily multi-threaded server applications. Occasionally, I also get to write a client application. Except for some HTML+CSS experiments in college, I’ve never worked on web applications. Hence, I have never written a single line of JavaScript code.

Part of the reason is that I’m skeptical of dynamic languages in general. I have done some Python development and on more than one occasion I have tripped over issues that would have been easily avoidable in a language with strong typing and compilation.

Enter Anders Hejlsberg.

He’s one of my favorite people in software development. That’s not very surprising  as he is the “father” of Turbo Pascal, Delphi and C#, the three languages that have determined my path as a software developer from my very first line of code till now.

His latest project has been TypeScript, a superset of JavaScript that basically adds everything that’s been missing from the language to make it useful for larger development projects. This is, in my opinion, exactly what that language needed and I don’t know why anyone would still be writing pure JavaScript instead of switching to TypeScript.

So in an effort to branch out and learn something new this year, I really want to learn TypeScript and develop something useful in it.

Distributed Version Control

I’ve been an avid reader of Joel Spolsky’s Joel on Software since the beginning of college (i.e. for more than ten years now). So I first heard about distributed version control when his company FogCreek was developing Kiln and he published Hg Init, a Mercurial tutorial.

I didn’t think much of it, because I was mostly a coder then and didn’t care about the tools used throughout the development lifecycle other than my IDE. As more and more of my work is in project management and other “meta” tasks these days, I now know what an impact the right choice of tools has on workflow and productivity. This is why I was particularly interested in this session and hearing peoples’ experience with real-world DVCS usage.

I mostly use Perforce, though for some things I have to put up with CVS (which I’d rather not talk about). Looking at a DVCS such as Mercurial I can see how someone coming from CVS or Subversion could get a lot of value out of switching to a DVCS. However, a lot of the supposed advantages of using a DVCS, I think, are really things you can do with a centralized version control system; such as larger number of smaller check-ins instead of just one check-in a day or one a week. It’s really just a question of how you and your team decide to work. With the way I use Perforce, I think I’m already doing 90% of what’s supposedly so great about DVCS.

One thing I was quite shocked by was learning how many people in the audience did not use a real version control system at all. Instead they used group messaging to tell others what they are working on and thus “lock” a file, or resorted to regularly zipping and archiving their code manually.


As a next step, I want to give Kiln a try (it’s free for up to two users) by storing my .NET Gadgeteer code there. This is a project I stared about two years, yet never really finished. But once the code is there, I want to improve it and finally get it working with Wifi. For that, I’m also going to get the latest version of Visual Studio Express as that comes with full support for TypeScript and I can play with that, too. We’ll see how it goes.

Final thoughts

It was a fun day and even though I don’t do much with Delphi these days, it’s nice seeing the community. I like the fact that it’s rather small and you have the same people popping up everywhere. If you’ve ever asked a Delphi question on Stack Overflow, you’ve probably interacted with some of them already.

Reading up on Windows Server 2008 R2

For reasons I would rather not into detail about, I had to help with setting up a Windows Server 2008 R2 machine. Researching this, I found this great video on Channel 9 from PDC 2009 by Mark Russinovich: Windows 7 and Windows Server 2008 R2 Kernel Changes Part 1 and Part 2.

Here are a couple of the key takeaways from that talk from a performance point-of-view.


It’s been said before and even made it into a Forbes article, but it’s worth repeating, because many applications (even major ones) get it wrong anyway:

Don’t mess with the system timer resolution (via timeBeginPeriod) because it will increase overhead and thus reduce performance.

I remember having a system where Sysinternals ClockRes showed the timer resolution being way higher (i.e. lower tick interval) than it should have been. Unfortunately, I had no idea what application was responsible for this. In Server 2008 R2, however, one has a way of finding out:

powercfg.exe -energy duration 5

This will produce an HTML report showing you a couple of things that can have an impact on your system’s power consumption (and performance), including the processes that changed the timer resolution.

Power Plan

Also in this report is your system’s power plan. The default is Balanced, which may not be the best choice under certain circumstances. I found a couple of good articles on the topic:

Scott Hanselman’s blog post in particular left me convinced that High Performance was the way to go, given my intended use for this server is pretty close to what he described.

Dispatcher Lock Gone

In my own testing I noticed that the same application on Windows Server 2008 R2 was scaling much better with more threads than it did on Windows Server 2003 (R2). I’m not sure I have (the absence of) the dispatcher lock to thank for that, but I here’s what I noticed:

  • On Server 2003, multiple threads would not use all of the available CPU, and queues of outgoing messages would built up. Distributing the work over more threads did not improve overall throughput.
  • On Server 2008 R2 with the same number of threads, there were no queues in data processing and we reached a limit only when the NIC exceeded 90% utilization.

This was far better than I had expected. To be fair, I have not tested to what degree the increase in performance can be attributed to newer hardware versus the newer operating system. But since I can’t have one without the other, I don’t think it matters.

A Cautionary Tale

I am not entirely sure whether this is related to the absence of the dispatcher lock, but migrating to Server 2008 R2 also revealed a very nasty concurrency problem in one application. The code had been running fine for many years on Server 2003, but failed rather quickly on Server 2008 R2. My guess is that the increased degree of parallelism in 2008 R2 just made it more likely for the race condition to reveal itself.

It also shows that upgrading from 2003 to 2008 R2 (or newer) does require some testing. Even though I have not run into any APIs that were changed, there appear to be subtle timing changes such as this one that could make an application stumble.


I was pretty amazed how much better our Server 2008 R2 machines performed compared to the old 2003 machines after checking the settings mentioned above. If there are other’s I have missed, please leave a comment.

I still have to research the changes coming in Server 2012 (R2), maybe Windows Server got even better in that version.

Experimenting Some More

Normally, on a Sunday like this I would go running in one of the nearby parks. However, a month ago Düsseldorf was struck by one of the worst storms in recent history and about 17 000 trees in this city alone were destroyed or damaged.

The fire department (helped by other emergency services and even combat engineers from the army) did a tremendous job clearing the streets and allowing public transportation to resume within a few days. Despite the severity of the storm, the impact on public life was rather low.

The city’s many other patches of green including the parks I use to go for a run, though, are still not entirely safe again. So many of them have been closed off to the public out of fear that some loose branches might fall down (although I haven’t heard of anybody getting injured after the initial storm).

So instead of running, I took out my camera and shot what the areas I would usually run at looked like. Not a pretty picture.

Panorama Black & White

Detail Black & White

On a more positive note, here’s a shot I did experimenting with my new 18-250mm lens last week. After borrowing my father’s lens a while ago, I was so taken with its possibilities, I just had to get my own.

By the way, the bottom picture in that post was taken in the same park (though not the same spot) as the ones above. Once the park is accessible again, I’ll try to recreate the shot. I’m afraid there is going to be considerably less green there.

Smart Herb Garden

One of the most fun projects I backed on Kickstarter has been Smart Herb Garden from Click & Grow.

I don’t cook a lot; in fact I barely spend any time in my kitchen. But still, I’ve been very excited about watching this thing grow. The first batch of seeds I’ve “planted” was Basil, Mini Tomatoes and Salad Rocket.

Below are a couple of pictures documenting my garden grow. I’ll update this page as time goes on and harvest approaches.

18 April 2014: Unpacking

Smart Herb Garden

13 May 2014: Seeds planted

Smart Herb Garden

21 May 2014: First Green

First Green

25 May 2014

Smart Herb Garden

29 May 2014

Smart Herb Garden (1)


At night, the light casts a very interesting pattern onto the ceiling of my kitchen.


Random Pictures

If I were asked what my hobbies were, I probably wouldn’t list photography among them. Nonetheless, I like to grab my camera every now and then and take some pictures. And sometimes, I even like to sit down afterwards and fiddle around a bit in Photoshop Elements to touch them up.

Here is a random selection of some of the more recent ones. I take most of my pictures while traveling, so you’ll find them included with one of my Travel posts.

In Orbit von unten

Frische Luft und Kamillentee