Re-running the ECE upgrade

By default, re-running the elastic-cloud-enterprise.sh upgrade command resumes the previous ECE upgrade process. However, if your previous ECE upgrade attempt got stuck (for example, due to infrastructure problems, a host going offline, or similar) and re-attempting the upgrade still results in the upgrade process being blocked, run elastic-cloud-enterprise.sh upgrade --force-upgrade to ensure that any existing upgrade state gets cleared before starting the new ECE upgrade process.

The --force-upgrade parameter is also helpful in situations where the Elastic Cloud Enterprise platform is already upgraded to the desired target version but there are containers still running at the old version. These rare situations can also be caused by infrastructure issues, for example, runners temporarily going offline and not being "seen" by the upgrade process. Running elastic-cloud-enterprise.sh upgrade --force-upgrade with the same target version makes the Elastic Cloud Enterprise upgrader perform the upgrade procedure anyway, thereby covering any containers that failed to upgrade previously.