GitOps the Hard Way, with Argo CD

Syncing Only the Resources That Changed

The ApplyOutOfSyncOnly option limits a sync to the resources that actually changed.

By default, Argo CD applies every object in an Application on each sync. For an Application with many resources, this is slow and mostly redundant. ApplyOutOfSyncOnly=true limits the sync to resources that are actually out of sync. It is still a full sync, sync hooks run and the operation is recorded in history, but the unchanged resources are skipped.

Concretely, an Application with 500 resources where 3 changed: a default sync makes about 500 apply calls, 497 of them no-ops. With ApplyOutOfSyncOnly=true, it makes 3.

apiVersion: argoproj.io/v1alpha1
kind: Application
metadata:
  name: todo-app
  namespace: argocd
spec:
  destination:
    namespace: default
    server: https://kubernetes.default.svc
  project