Stateful sets with Kubernetes

In one of my previous posts, we have looked at deployment controllers which make sure that a certain number of instances of a given pod is running at all times. Failures of pods and nodes are automatically detected and the pod is restarted. This mechanism, however, only works well if the pods are actually interchangeable…More

Superconducting qubits – on islands, charge qubits and the transmon

In my previous post on superconducting qubits, we have seen how a flux qubit represents a qubits state as a superposition of currents in a superconducting loop. Even though flux qubits have been implemented and used successfully, most research groups today focus on different types of qubits using a charge qubit as an archetype. Charge…More

Kubernetes storage under the hood part II – persistent storage

The storage types that we have discussed so far realize ephemeral storage, i.e. storage tied to the lifecycle of the Pod on a specific node. Of course, there are many use cases like databases or other stateful applications that require storage that is persistent and has a lifecycle independent of the Pod. In this post,…More

Superconducting qubits – the flux qubit

In the last post, we have discussed the basic idea of superconducting qubits – implement circuits in which a supercurrent flows that can be described by a quantum mechanical wave function, and use two energy levels of the resulting quantum system as a qubit. Today, we will look in some more detail into one possible…More

Kubernetes storage under the hood part I – ephemeral storage

So far, we have mainly discussed how compute and network resources are used and managed with Kubernetes. We will now turn to the third fundamental element of a container platform – storage. Docker storage concepts Before we talk about Kubernetes storage concepts, let us first recall how storage is managed in Docker. The following tests…More

Superconducting qubits – an introduction

In some of the last posts in my series on quantum computing, we have discussed how NMR (nuclear magnetic resonance) technology can be used to implement quantum computers. Over the last couple of years, however, a different technology has attracted significantly more interest and invest – superconducting qubits. What are superconducting qubits? To start with…More

Managing traffic with Kubernetes ingress controllers

In one of the previous posts, we have learned how to expose arbitrary ports to the outside world using services and load balancers. However, we also found that this is not very efficient – in the worst case, the number of load balancers we need equals the number of services. Specifically for HTTP/HTTPS traffic, there…More

Quantum teleportation

Quantum states are in many ways different from information stored in classical systems – quantum states cannot be cloned and quantum information cannot be erased. However, it turns out that quantum information can be transmitted and replicated by combining a quantum channel and a classical channel – a process known as quantum teleportation. Bell states…More

Watching Kubernetes networking in action

In this post, we will look in some more detail into networking in a Kubernetes cluster. Even though the Kubernetes networking model is independent of the underlying cloud provider, the actual implementation does of course depend on the cloud provider which communicates with Kubernetes through a CNI plugin. I will continue to use EKS, so…More