Achieving Failover using Docker, Kubernetes, Apache Kafka and ZooKeeper

In today’s world, the cloud dominates most of what we access online. Rarely are websites still hosted on a single server in a single location. Most of the time, software is written with clustering and cloud in mind.

Developing clustered web based systems requires some unique thinking about architecture and synchronization. In this post I’d like to outline a project I have written in summer 2018 to achieve automatic recovery for a clustered system when one of it’s components blacks out.

Continue reading “Achieving Failover using Docker, Kubernetes, Apache Kafka and ZooKeeper”

Hexbug Inchworm Update

Just a quick heads up (I know it’s been months but better late than never ;))

I’m having trouble completing my Hexbug Inchworm project due to the small size of the Hexbug. It’s hard to accomodate an arduino and a battery, and my previous attempts at mounting the arduino on top have had influence on the movement due to a change of the center of mass. I didn’t like how wobbly it had become. It couldn’t even walk straight anymore. So this is why I’ve been scouting for parts mostly since the last entry.

To make matters worse, I’m still not sure if I should just stick with the robot wandering around aimlessly or if I would like some more sophisticated means of movement (which would necessitate additional sensors).

So there it is. I’m back to the planning board and searching for parts and that’s why there’s no cool autonomous hexbug yet.

Someday, maybe. 🙂

Why I left Philipps-Universität Marburg (and enrolled at Mittelhessen University of Applied Sciences)

I never wrote about why I left Marburg and enrolled at THM. I guess now is a good time as any to explain this decision.

Back when I finished school and gained my general qualification for university entrance I didn’t think I’d need to put much thought into where and what I would study. I already knew I would continue to pursue becoming a software developer. And as I just can’t afford to go living someplace else, I had to stay where I grew up. So why not stay in the city where I went to school?

Oh boy, was that a mistake… Continue reading “Why I left Philipps-Universität Marburg (and enrolled at Mittelhessen University of Applied Sciences)”

Some C, finally

After this Winter Semester I can now finally count C as one of the languages I am comfortable in.

I learned programming C in a course that could loosely translate to “programming close to system” or “machine oriented programming”.

We devised a virtual machine for the ninja programming language that was designed from the ground up as a stack machine. A stack machine is a easy start as you can quickly design the stack and binary operations that consume operands from the stack and produce one new result to be pushed on the stack.

We started with a purely integer based stack, because we wanted the encoding of instructions to be conceptualized before we added an object based stack.

The encoding of instructions went like so: Continue reading “Some C, finally”

Component based Entity System

Notice: This is a post I reposted from my old website.

Started development of a basic Entity-Component-Framework where Entities are limited to an abstract implementation where no actual “Entity” exists. An Entity is made up of different components.

Components have no real “logic” included in them. They are merely containers for values. E.g. a PositionComponent only holds x,y values, whereas a ImageComponent contains a image variable of some sort.

Systems operate on Entities which contain the apropriate number and type of component. A MovementSystem only operates on Entities that have a PositionComponent as well as a VelocityComponent.

Real simple stuff. But it really helps because it lays heavy emphasis on composition instead of inheritance which can make many things a lot simpler 🙂

I will put it on bitbucket later so everyone can check out the code.

Edit: You can now find the code at my bitbucket –click-.

New Site!

Today I sat down and had a little thought. I was proud of my quirky diy CMS, but it led to me not updating it.

As I went to check up on my site, I noticed my last post was around spring 2015. Seeing as it’s close to 2017 now, I knew something had to change. Oh, and PHP was so outdated I was about to have my site shut down. Oops.

I reckon there is still work to be done around here, but this seems like a good start.

PS: If you used any services I used to provide and you noticed they are now broken, please contact me so we can work it out. I really don’t like when services I depend on stop working, so I’ll do my best to get everything back on track if you tell me!