Chapter 2. OpenShift Container Platform Versioning Policy

OpenShift Container Platform provides strict backwards compatibility guarantees for all supported APIs, excluding alpha APIs (which may be changed without notice) and beta APIs (which may occasionally be changed in a non-backwards compatible manner).

Red Hat did not publicly release OpenShift Container Platform 4.0 and, instead, released OpenShift Container Platform 4.1 directly after version 3.11.

The OpenShift Container Platform version must match between master and node hosts, excluding temporary mismatches during cluster upgrades. For example, in a 4.2 cluster, all masters must be 4.2 and all nodes must be 4.2. If you installed an earlier version of oc, you cannot use it to complete all of the commands in OpenShift Container Platform 4.2. You must download and install the new version of oc.

Changes of APIs for non-security related reasons will involve, at minimum, two minor releases (3.11 to 4.1 to 4.2, for example) to allow older oc to update. Using new capabilities may require newer oc. A 4.2 server may have additional capabilities that a 4.1 oc cannot use and a 4.2 oc may have additional capabilities that are not supported by a 4.1 server.

Fully compatible.

oc client may not be able to access server features.

oc client may provide options and features that may not be compatible with the accessed server.