Availability of cf push
during TAS for VMs upgrades varies from release to release. Considerations that can affect cf push
availability include Cloud Controller database (CCDB) migrations and the number of VMs in use. However, cf push
is generally available for the duration of an upgrade.
Having a single VM in use, such as a WebDAV, a Gorouter, a UAA, or a Cloud Controller, affects whether cf push
is available during an upgrade.
If you have scaled out your app to achieve high availability and are not using WebDAV, cf push
should be available for the entire duration of the upgrade. However, upgrades to certain versions of TAS for VMs sometimes require a CCDB schema or data migration, which may cause cf push
to be unavailable while Cloud Controllers are rolling during the upgrade.
The Cloud Controller API is taken down during the pre-backup-lock
stage of a BBR backup and put back up again during the post-backup-unlock
stage. As a result, the cf push
command becomes unavailable during that time. However, the backup that takes place between those stages is very short, generally only a few minutes. The bulk of the BBR backup operation happens after the post-backup-unlock
stage, so the Cloud Controller API and cf push
are available for most of the duration of a BBR backup.
The Uptimer tool can help you measure the availability of thecf push
command during an upgrade. For more information, see the Uptimer repository on GitHub.