Quantum Theory and Microservices

I just read an interesting book about quantum theory by Hans-Peter Dürr. In this book Hans-Peter Dürr criticizes the classical physics sciences by describing the constantly attempt to find the smallest component of physics – the atom – in the hope to answer the last question. But it is the quantum theory that shows that this smallest building block does not exist at all and that everything is connected to everything and that there is ultimately only the ONE. I myself find this theory very difficult to understand, but it has brought me to something that we can also observe in modern software architecture – the microservice architecture.

The idea of microservice architecture is to split complex systems into smaller building blocks – the services. This usually works very well in the beginning, up to the point where the individual services have to be connected to each other to meet certain requirements. At this point, the concepts of choreography and orchestration come into play. These concepts are well documented within the microservice architecture by the SAGA Pattern. I have published some blogs and articles on this topic myself. So I don’t think this architecture is a bad idea.

But it is interesting to note that this approach is very similar to the model of classic physics criticized by Hans-Peter Dürr. We build various tiny services and feel very superior in a project, as we can isolate and release a single function in the shortest possible time. But then comes the moment when we have to implement interactions. Our service must cooperate with all the other tiny services. And suddenly things are no longer so simple and isolated. We notice that everything is related and we can only be successful with openness and cooperation. But often the corresponding structures are missing in large software projects. Then we try to insist on the functionality of our so beautiful tiny isolated services. We’re not ready to see the world out there as it really is. And sometimes software projects fail at this point.

Isn’t it surprising that in the end we always keep falling back on the same realization?

Ceph Octopus running on Debian Buster

In my previous blog I explained how to run the Ceph Storage System on Debian 9. In the mean time the new version 15 (Octopus) was released. And this version not only runs on Debian 10 (Buster) it also provides a complete new install process. In the previous release of ceph you had to run the command line tool ‘ceph-deploy’. This tool was not so easy to manage and there was a lot of work to get ceph running.

With the new Octopus release there is a new admin tool called cephadm. This tool is based on docker which means there is no need to install additional tools or libraries on your host. The only thing you need is a server running docker. You can find a installation guide for docker on Debian Buster here. Or you can take a look at my Imixs-Cloud project providing an easy way to setup a Kubernetes environment. Information about Ceph Octopus release can be found here. So let’s start with the installation….

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Microsoft Teams on Linux

I am not a friend of Microsoft at all but for some reasons I need the Tool Microsoft Teams for some of my customer projects. In the past it was not possible to join a meeting from a Linux machine. But to be honest, Microsoft is working a lot in the Linux world and also contributes a lot of code. So Microsoft is now also supporting Teams .

To install Teams on Linux Debian is quite simple:

1. Download the Debian packages ‘teams….._amd64.deb’ from the microsoft official download page:
https://teams.microsoft.com/downloads#allDevicesSection

2. To install the package from your download run:

$ sudo dpkg -i teams_1.x.xx.xxx_amd64.deb

3. Now you can launch Microsoft Teams:

$ teams

Note: To use teams you should create a Microsoft Account. I am not sure if this is really necessary but I have had already an account.

Stop Microsoft Teams From Starting Automatically on Debian/Gnome

One of the most nasty features of Teams for Linux is that it starts automatically after a reboot and it will stay in background even if you have closed teams. This is an immorality, however, that can easily be avoided.

Within teams there is a ‘Settings’ dialog page where you can deactivate autostart function:

If you deactivate the first two application options Teams will be closed completely after you close the teams window. So you can be sure teams is not exchanging data in the background anymore.

To start teams manually again run:

$ teams

Kubernetes and GlusterFS

In this Blog I will explain how to install a distributed filesystem on a kubernetes cluster. To run stateful docker images (e.g. a Database like PostgreSQL) you have two choices.

  • run the service on a dedicated node – this avoids the lost of data if kubernetes re-schedules your server to another node
  • use a distributed storage solution like ceph or glusterfs storage

Gluster is a scalable network filesystem. This allows you to create a large, distributed storage solution on common hard ware. You can connect a gluster storage to Kubernetes to abstract the volume from your services. 

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Howto Install Ceph on CentOS 7

In this blog I will explain how to install the Ceph storage system on CentOS. In my previous blog I showed how to install ceph on Debian. But the newer version of ceph are not supported by Debian and Ceph is much better supported by CentOS because RedHat maintains both CentOS and Ceph.

In this blog I will install Ceph ‘Nautilus’ on CentOS 7. You will find detailed information about ceph and the installation process for nautilus release here.

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Kubernetes – Storage Volumes with Ceph

In this blog I show how to setup a Kubernetes Storage Volume with Ceph. I assume that you have installed already a kubernetes cluster with one master-node and at least three worker-nodes. On each worker node you need a free unmounted device used exclusively for ceph. Within the ceph cluster I setup a Ceph Filesystem (CephFS) that we can use as a storage volume for kubernetes.

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Kubernetes – Setup Traefik 2.1

In my last blog about Traefik I showed how you can setup Traefik version 1.7 in a Kubernetes cluster. In this blog I will explain how to use the latest version 2.1 of Traefik. Version 2.x Traefik implements some new concepts and need of course a different setup. This blog post assumes that you have already an up and running Kubernetes master node and at lease one worker node. See also my Blog ‘From docker-swarm to kubernetes. You can find also detailed information in the official traefik website. A helpful tutorial can also be found here.

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Kubernetes – Setup Traefik 1.7

In my last blog I showed how you can setup a Kubernets cluster by your own. If your cluster is running in the internet you need some kind of load balancer to access your apps from outside. Traefik is a popular load balancer and reverse-proxy service useful also in a KUbernetes cluster. This tutorial is based on Traefik 1.7 and assumes that you have already an up and running Kubernetes master node and at lease one worker node. You can find also detailed information in the official traefik website.

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