From d7c5e97f2edf63e43cd560fc1a2a6b0d41f0cf15 Mon Sep 17 00:00:00 2001 From: Paul Wright <5154224+pwright@users.noreply.github.com> Date: Mon, 13 Jan 2025 11:44:00 +0000 Subject: [PATCH] update link-cost (#254) * update link-cost --- cli/link-cost.adoc | 14 +++++++++++++- partials/attributes.adoc | 1 + 2 files changed, 14 insertions(+), 1 deletion(-) diff --git a/cli/link-cost.adoc b/cli/link-cost.adoc index 24e0a0f..dfcc7c5 100644 --- a/cli/link-cost.adoc +++ b/cli/link-cost.adoc @@ -1,3 +1,4 @@ +include::../partials/attributes.adoc[] // Type: procedure [id="specifying-link-cost"] == Specifying link cost @@ -79,4 +80,15 @@ You can view the traffic levels corresponding to each client. NOTE: If there are multiple clients on different sites, filter the view to each client to determine the effect of cost on traffic. For example, in a two site network linked with a high cost with servers and clients on both sites, you can see that a client is served by the local servers while a local server is available. --- \ No newline at end of file +-- + +A common use-case for specifying cost is to provide automatic failover. +As described in {single-link}, you might have two instances of a server with a high cost for the link to the backup server: + +* local server (effective cost = 0) +* remote server (link cost = 99999) + +In this case, connections are always routed to the local server and fails over to the remote server when the local server becomes available. + +Some complex applications, especially stateful ones, require "orchestrated" failover, meaning you need control over the order in which traffic is redirected from one set of workloads to another. +{skupper-name} does not offer this type of orchestration, you need to implement that orchestration for those applications. diff --git a/partials/attributes.adoc b/partials/attributes.adoc index cf015a2..b978ac7 100644 --- a/partials/attributes.adoc +++ b/partials/attributes.adoc @@ -17,6 +17,7 @@ :kube-ref-link: https://skupper.io/docs/kubernetes-reference/index.html[Skupper Kubernetes CLI reference] :pod-ref-link: https://skupper.io/docs/kubernetes-reference/index.html[Skupper Podman CLI reference] :cost-link: ../cli/index.html#specifying-link-cost[Specifying link cost] +:single-link: ../cli/index.html#deploying-single-logical-service[Deploying a single logical service] :skupper-operator-name: Skupper operator