Recommendations

This page describes a list of things that could help you get the best experience out of your cluster.

Note: You do not need to follow this documentation in order to use your cluster

Ingress and cert-manager

To make it easier to expose applications an ingress controller is commonly deployed.

An ingress controller makes sure when you go to a specific webpage you are routed towards the correct application.

There are a lot of different ingress controllers available. We on Elastx are using ingress-nginx and have a guide ready on how to get started. However you can deploy any ingress controller you wish inside your clusters.

To get a single IP-address you can point your DNS towards we recommend to deploy an ingress-controller with a service of type LoadBalancer. More information regarding Load Balancers can be found in this link.

In order to automatically generate and update TLS certificates cert-manager is commonly deployed side by side with an ingress controller.

We have created a guide on how to get started with ingress-nginx and Cert-manager that can be found here in this link to guide.

Requests and limits

Below we describe requests and limits briefly. For a more detailed description or help setting requests and limits we recommend to check out Kubernetes documentation: https://kubernetes.io/docs/concepts/configuration/manage-resources-containers/

Requests

Requests and limits are critical to enable Kubernetes to make informed decisions on when and where to schedule and limit your workload.

Requests are important for the scheduler. Requests can be seen as “Amount of resources the pod would utilize during normal operation”. This means that the scheduler will allocate the required amount of resources and make sure they are always available to your pod.

Requests also enables the auto-scaler to make decisions on when to scale a cluster up and down.

Limits

Limits define the maximum allowed resource usage for a pod. This is important to avoid slowdowns in other pods running on the same node.

CPU limit. Your application will be throttled or simply run slower when trying to exceed the limit. Run slower equals to fewer cpu cycles per given time. That is, introducing latency. Memory limit is another beast. If any pod trying to use memory above the the limit, the pod will be Out of memory killed.

Autoscaling

Autoscaling can operate on both node-level and pod-level. To get the absolute best experience we recommend a combination of both.

Scaling nodes

We have built-in support for scaling nodes. To get started with autoscaling we recommend to check the guide in this link.

Scaling pods

Kubernetes official documentation has a guide on how to accomplish this in this piece of documentation.

In short, node autoscaling is only taken into consideration if you have any pods that cannot be scheduled or if you have set requests on your pods. In order to automatically scale an application pod scaling can make sure you get more pods before reaching your pod limit and if more nodes are needed in order to run the new pods nodes will automatically be added and then later removed when no longer needed.

Network policies

Network policies can in short be seen as Kubernetes built in firewalls.

Network policy can be used to limit both incoming and outgoing traffic. This is useful to specify a set of pods that are allowed to communicate with the database.

Kubernetes documentation have an excellent guide on how to get started with network policies in this link.

Pod Security Standards / Pod Security Admission

Pod Security Admission can be used to limit what your pods can do. For example you can make sure pods are not allowed to run as root.

In order to get to know this more in detail and getting started we recommend to follow the Kubernetes documentation in this link.

Load Balancers

Load Balancers allow your application to be accessed from the internet. Load Balancers can automatically split traffic to all your nodes to even out load. Load Balancers can also detect if a node is having problems and remove it to avoid displaying errors to end users.

We have a guide on how to get started with Boad Balancers in this link.