Cassandra and Kubernetes with K8ssandra

Cassandra is a kick-ass database. It's reliable and works pretty well for insert heavy workloads. Cassandra does well with reads as well as long as you design your tables with your access patterns in mind. In order to work well with Cassandra, you need to avoid Tombstones either by avoiding deletes and updates or by avoiding collections. Cassandra cluster configuration and distribution can be tricky and also repairs can be a challenge at scale. K8ssandra is a complete Cassandra distribution with observability(Grafana and Prometheus) and a simple solution for repairs called Reaper. You also need to keep in mind that by using Cassandra in containers you will lose throughput. Let's say you want to explore Cassandra and you are already using kubernetes or you have a tier 2 or 3 need or even want to save some cost in your development environment that could be an interesting solution. Today I will show how to install K8ssandra in Minikube.

Installing K8ssandra

You will need to have Minikube and helm installed on your machine. Helm is a package manager for kubernetes and works based on a template(similar to Terraform) makes it super easy to install the software in kubernetes. 

#!/bin/bash

#
# Minukube setup
#
minikube start --memory=8192 --cpus=8 -p k8ssandra 

#
# k8ssandra
#

helm repo add k8ssandra https://helm.k8ssandra.io/
helm repo add traefik https://helm.traefik.io/traefik
helm repo update
helm install k8ssandra-tools k8ssandra/k8ssandra
helm install k8ssandra-cluster-a k8ssandra/k8ssandra-cluster

#
# Traefik
#

helm repo add traefik https://helm.traefik.io/traefik
helm repo update
helm install traefik traefik/traefik -n traefik --create-namespace -f traefik.values.yaml

minikube service traefik -n traefik --url -p k8ssandra
xdg-open "http://192.168.99.121:32090/dashboard/#/"

#
# Grafana / Prometheus
#

helm upgrade k8ssandra-cluster-a k8ssandra/k8ssandra-cluster --set ingress.traefik.enabled=true --set ingress.traefik.monitoring.grafana.host=grafana.localhost --set ingress.traefik.monitoring.prometheus.host=prometheus.localhost
view raw k8ssandra.md hosted with ❤ by GitHub

Using The Services

So before we use the services we need to perform some port forward. For each command open a new terminal window or tab:

kubectl port-forward service/grafana-service 3000:3000

kubectl port-forward service/prometheus-operated 9090:9090 

kubectl port-forward service/k8ssandra-cluster-a-reaper-k8ssandra-reaper-service 8080:8080

kubectl port-forward service/k8ssandra-dc1-all-pods-service 9049:9042

Traefik http://192.168.99.121:32090/dashboard/#/










Grafana http://localhost:3000/










Prometheus http://localhost:9090/










Cqlsh









All scripts and configs are available at my github here. Have Fun.

Cheers,

Diego Pacheco

Popular posts from this blog

Having fun with Zig Language

Image
Zig is a general-purpose language created in 2016 by Andrew Kelly .  Zig aims to fix the issues C language has while being pragmatic and simple at the same time. Zig really shines as being simple by not having any hidden control flows, not having hidden memory allocations, no pre-processors, and no macros. Basically, it's one language and one language only. Since pre-processors and macros can get really complex and become their own universe. Sure it's not the Zig Philosophy.  Zig Compiler(Zig cc) also is a C compiler, and the interoperability from C to Zig is very good. Clearly, we can see influence from other languages like Go and Rust; however, Zig is pretty unique and different from Go and Rust.  Zig is fast. Zig is perfect for system programming. I bet we will see a lot of solutions being built in Zig. As a languages aficionado, I like to learn at least one language per year and sometimes more; Zig was my 2021 pick, did not regret it. Even if you dont use all language...
Keep reading

C Unit Testing with Check

Image
When I start on IT, several years ago(+15), C was the first language that I learned. But was not the first language I mastered and deployed in production which was...surprisingly Visual Basic 6.0. However, when I learned C or any language back on that old and arcane time noddy was into testing. However now is impossible to work professionally in any language without tests. C is a low-level language but still kicks ass and has several interesting libs/frameworks. People use to fear C a lot because of lack of syntactical sugar but once you get used to it is not that hard at all. Today I want to show how you can do Unit Testing with C. I will not show how to do Unit Testing with C++ but with C ANSI actually. We will be using Check a unit test lib for C ANSI.
read more »

Cool Retro Terminal

Image
I often don't blog about this kind of stuff. Yesterday I friend of mine showed me this awesome project called  cool-retro-term . When you work with Cloud Computing and DevOps Engineering you spend lots of time on the black screen testing things on the cloud.  When I saw this project I got very excited because it brings some nostalgy back to my life. To be 100% clearI'm not that old as my friend :-) However I share his joy into this retro terminals. This also reminds me some old games like Fallout 1 . I just this is pure fun so I'm sharing here with you guys some screenshots and also how to run on Gnome Ubuntu 17.04.
read more »