Is ETCD required for Kubernetes?

Kubernetes is a distributed system, so it needs a distributed data store like etcd.

What happens if ETCD goes down Kubernetes?

If the majority of etcd members have permanently failed, the etcd cluster is considered failed. In this scenario, Kubernetes cannot make any changes to its current state. Although the scheduled pods might continue to run, no new pods can be scheduled.

What does ETCD do in Kubernetes?

etcd is an open source distributed key-value store used to hold and manage the critical information that distributed systems need to keep running. Most notably, it manages the configuration data, state data, and metadata for Kubernetes, the popular container orchestration platform.

What information is stored in ETCD Kubernetes?

Etcd stores Kubernetes cluster configuration and state data such as the number of pods, their state, namespace, etc. It also stores Kubernetes API objects and service discovery details.

Why do we need Kubernetes and other orchestrators above containers?

Kubernetes orchestration allows you to build application services that span multiple containers, schedule containers across a cluster, scale those containers, and manage their health over time. For this reason, Kubernetes is an ideal platform for hosting cloud-native apps that require rapid scaling.

Is etcd persistent?

etcd stores data in a multiversion persistent key-value store. The persistent key-value store preserves the previous version of a key-value pair when its value is superseded with new data.

What if Kubernetes master dies?

Master in Kubernetes is a node that controls and manages a group of worker nodes. If you have a Single-Master architecture, then it becomes a problem, if the master node goes down, and then you cannot create more services and pods, etc. and the cluster fails.

How does etcd store data?

The Kubernetes API server stores each cluster’s state data in etcd. Kubernetes uses etcd’s “watch” function to monitor this data and to reconfigure itself when changes occur. The “watch” function stores values representing the actual and ideal state of the cluster and can initiate a response when they diverge.

What database does etcd use?

etcd stores data (both key and value) as a binary array; the end user can apply whatever typing they want (often by storing values as JSON). And etcd uses a btree to index the keys, which is the same indexing that most any other DB uses on generic data.

What is etcd in Kubernetes and how to backup it?

etcd is a consistent and highly-available key value store used as Kubernetes’ backing store for all cluster data. If your Kubernetes cluster uses etcd as its backing store, make sure you have a back up plan for those data. You can find in-depth information about etcd in the offical documentation. Before you begin.

Where does Kubernetes store all its data?

A Kubernetes cluster stores all its data in etcd. Anything you might read from a kubectl get xyz command is stored in etcd. Any change you make via kubectl create will cause an entry in etcd to be updated. Any node crashing or process dying causes values in etcd to be changed.

What is a Kubernetes cluster?

One that runs on several machines at the same time. One that makes it easy to store data across a cluster and watch for changes to that data. Kubernetes uses etcd as its database. The only nuance is that etcd is a distributed database – because Kubernetes is a distributed system.

How to backup Kubernetes cluster with built-in snapshot?

In order to keep the sensitive Kubernetes data safe, encrypt the snapshot files. Backing up an etcd cluster can be accomplished in two ways: etcd built-in snapshot and volume snapshot. etcd supports built-in snapshot.