Kubernetes v1.36: New Metric for Route Sync in the Cloud Controller Manager
This article, originally misdated, now reflects a May 15, 2026, publication date. Kubernetes v1.36 introduces a new alpha metric, route_controller_route_sync_total, for the Cloud Controller Manager's route controller. This metric tracks route sync operations with the cloud provider, aiding in monitoring the CloudControllerManagerWatchBasedRoutesReconciliation feature gate. This feature, introduced in v1.35, switches the route controller to a watch-based approach. This change reduces API calls by only reconciling routes when nodes change. To test the new feature, compare the metric's behavior with the feature gate disabled and enabled. With the feature gate disabled, the counter increments at a fixed interval. Conversely, with the feature enabled, the counter only increments upon node changes. This difference is most noticeable in stable clusters with infrequent node modifications. Feedback can be provided through Kubernetes Slack, a GitHub issue, and the SIG Cloud Provider community page. Further details are available in KEP-5237.
route_controller_route_sync_total, for the Cloud Controller Manager's route controller. This metric tracks route sync operations with the cloud provider, aiding in monitoring theCloudControllerManagerWatchBasedRoutesReconciliationfeature gate. This feature, introduced in v1.35, switches the route controller to a watch-based approach. This change reduces API calls by only reconciling routes when nodes change. To test the new feature, compare the metric's behavior with the feature gate disabled and enabled. With the feature gate disabled, the counter increments at a fixed interval. Conversely, with the feature enabled, the counter only increments upon node changes. This difference is most noticeable in stable clusters with infrequent node modifications. Feedback can be provided through Kubernetes Slack, a GitHub issue, and the SIG Cloud Provider community page. Further details are available in KEP-5237.