Posts tagged Kubernetes
Application updates are required as part of the normal maintenance process of your application lifecycle management. These updates should be as smooth as possible, and especially for a micro-services environment, performed with zero-downtime of your Payara Micro application. The Kubernetes Rolling Upgrades feature can help you with this.
The term “Kubernetes” comes from the Greek “kubernan,” which means to steer or guide. You can think of Kubernetes like a pilot for apps that are stored and run together in containers and other forms of workload distribution software. The Greek “kubernan” was transformed over the years to relate to the term “Govern”, which is another helpful comparison when trying to understand the full capacity of Kubernetes.
Kubernetes is most commonly used with Docker managed containers, although it doesn't strictly depend on it. Kubernetes defines a Container Runtime Interface (CRI) that container platforms must implement in order to be compatible. These implementations are colloquially known as "shims". This makes Kubernetes platform agnostic so that instead of Docker you're free to use other platforms with corresponding shims, such as CRI-O or KataContainers.
When using Docker images as the way to deploy your application, many organizations use Kubernetes to manage the containerized version of their application. This blog gives you a short overview of Kubernetes and how to run your Payara Micro application in a scaled fashion by either defining the scaling manually, or automatically by the Horizontal Pod scaler.
There's a lot of noise revolving around Docker at the moment, and with the current industry focus on the cloud, there's a good reason for that.
I hope you would already know why you might want to use Payara Platform in your business, so in this blog I'm going to focus more on why you'd specifically want to use it with Docker in a "business" context. For a start, if you're unfamiliar with Docker, please refer back to our introductory blog: What is Docker and How is it Used with the Payara Platform for a primer.
Payara Micro supports Hazelcast out of the box, and can be used for clustering. This allows members in the cluster to distribute data between themselves, amongst other things. By default, Hazelcast comes with multiple ways to discover other members in the same network. A multicast discovery strategy is commonly used for this purpose; a multicast request is sent to all members in a network and the members respond with their IP addresses. Another strategy must be employed if a member cannot or does not wish to provide their IP address.