From 436d3fe8c49db1e74e4679096bde456bbe90f739 Mon Sep 17 00:00:00 2001 From: Anubhav Vardhan Date: Wed, 14 Jul 2021 08:48:53 +0530 Subject: [PATCH] Update content/en/docs/tasks/administer-cluster/highly-available-control-plane.md Co-authored-by: chrismetz09 --- .../administer-cluster/highly-available-control-plane.md | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/content/en/docs/tasks/administer-cluster/highly-available-control-plane.md b/content/en/docs/tasks/administer-cluster/highly-available-control-plane.md index 622b80ec57..543abbfe44 100644 --- a/content/en/docs/tasks/administer-cluster/highly-available-control-plane.md +++ b/content/en/docs/tasks/administer-cluster/highly-available-control-plane.md @@ -136,7 +136,15 @@ the [etcd administration guide](https://etcd.io/docs/v2.3/admin_guide/#member-mi ![ha-control-plane](/images/docs/ha-control-plane.svg) ### Overview +The figure above illustrates three control plane nodes and their components in a highly available cluster. The control plane node’s components employ the following methods: +- etcd: instances are clustered together using consensus. + +- Controllers, scheduler and cluster auto-scaler: only one instance of each will be active in a cluster using a lease mechanism. + +- Add-on manager: each works independently to keep add-ons in sync. + +In addition, a load balancer operating in front of the API servers routes external and internal traffic to the control plane nodes. Each of the control plane nodes will run the following components in the following mode: * etcd instance: all instances will be clustered together using consensus; @@ -215,4 +223,3 @@ server coordination (for example, the `StorageVersionAPI` feature gate). [Automated HA master deployment - design doc](https://git.k8s.io/community/contributors/design-proposals/cluster-lifecycle/ha_master.md) -