From d4591c0eed06c19695939aa4004850c5ec0349c6 Mon Sep 17 00:00:00 2001 From: Steve Kriss Date: Tue, 20 Dec 2022 12:16:27 -0700 Subject: [PATCH] update docs on leader election (#4943) Signed-off-by: Steve Kriss Co-authored-by: Bhagwat kumar Singh --- site/content/docs/main/architecture.md | 6 +++++- site/content/docs/v1.23.2/architecture.md | 6 +++++- 2 files changed, 10 insertions(+), 2 deletions(-) diff --git a/site/content/docs/main/architecture.md b/site/content/docs/main/architecture.md index e65953c27b0..b29cb409d39 100644 --- a/site/content/docs/main/architecture.md +++ b/site/content/docs/main/architecture.md @@ -47,9 +47,13 @@ The following API objects are watched: ### Contour Deployment Contour is deployed in the cluster using a Kubernetes Deployment. -It has built-in leader election so the total number of replicas does not matter. +It has built-in leader election which is responsible for updating httproxy/ingress/gateway api resources via Kube API server. All instances are able to serve xDS configuration to any Envoy instance, but only the leader can write status back to the API server. +The data being served from contour instances are eventually consistent in an HA based deployment. +However HA mode is operationally scalable when you have high request rate from envoy to contour as requests are loadbalanced among contour instances. +This also helps availability zone /data center degradation events as your service continue to function. + ### Envoy Deployment Envoy can be deployed in two different models, as a Kubernetes Daemonset or as a Kubernetes Deployment. diff --git a/site/content/docs/v1.23.2/architecture.md b/site/content/docs/v1.23.2/architecture.md index e65953c27b0..b29cb409d39 100644 --- a/site/content/docs/v1.23.2/architecture.md +++ b/site/content/docs/v1.23.2/architecture.md @@ -47,9 +47,13 @@ The following API objects are watched: ### Contour Deployment Contour is deployed in the cluster using a Kubernetes Deployment. -It has built-in leader election so the total number of replicas does not matter. +It has built-in leader election which is responsible for updating httproxy/ingress/gateway api resources via Kube API server. All instances are able to serve xDS configuration to any Envoy instance, but only the leader can write status back to the API server. +The data being served from contour instances are eventually consistent in an HA based deployment. +However HA mode is operationally scalable when you have high request rate from envoy to contour as requests are loadbalanced among contour instances. +This also helps availability zone /data center degradation events as your service continue to function. + ### Envoy Deployment Envoy can be deployed in two different models, as a Kubernetes Daemonset or as a Kubernetes Deployment.