I'm new to kubernetes and etcd , i'm trying to figure out how etcd is distributed in kubernetes. the answer to these question will help me very much
Question 1: if we have a kubernetes architecture with 1 master and 2 nodes , are we going to have : - 1 etcd store that is located on the master - or an etcd distributed between the master and the nodes ( all will have a replication of the store )
if we have a kubernetes architecture with 2 masters and 3 nodes , are we going to have : - 2 etcd stores replicated on both the 2 masters - or an etcd distributed between the master and the nodes ( all will have a replication of the store )
Question 2: i found this recommandation "Always use an odd number of cluster members as quorum is needed to agree on updates to the cluster state" source : https://rancher.com/blog/2019/2019-01-29-what-is-etcd/ is it about the number of nodes in kubernetes cluster or is it about the number of members in the etcd cluster can you give me an example
Question 3: what does is mean: external clustered etcd , etcd runs as static pods on the master nodes
You are not supposed to have etcd on worker node. etcd should be either stacked within master nodes or should be external. Refer official docs.
Number of the etcd members should be odd to achieve quorum. In the blog that's what is being meant.
You can have etcd deployed on the master nodes as containers using static pods mechanism of kubernetes. Kubernetes will manage etcd as pods.
Alternatively you can run etcd as systemd unit on external hosts outside of your kubernetes cluster.