Istio 1.15 Upgrade Notes

When you upgrade from Istio 1.14.x to Istio 1.15.0, you need to consider the changes on this page. These notes detail the changes which purposefully break backwards compatibility with Istio 1.14.0. The notes also mention changes which preserve backwards compatibility while introducing new behavior. Changes are only included if the new behavior would be unexpected to a user of Istio 1.14.x. Users upgrading from 1.13.x to Istio 1.15.0 should also reference the 1.15.0 change logs.

Remote cluster management

Starting with Istio 1.15.0, a remote cluster is no longer automatically managed by the control plane to which it is attached. Remote clusters will now only be managed by a control plane if its cluster ID is specified with a topology.istio.io/controlPlaneClusters annotation on the system namespace of the remote cluster. This annotation must be added to a remote cluster BEFORE upgrading the corresponding control plane on an external or primary cluster.

Refer to the external control plane and multicluster primary-remote installation instructions for more details.