Normally, an OpenStack upgrade includes the following stages:
| # | Stage | Description |
|---|---|---|
| 1 | Planning | Includes the creation of the maintenance plan. |
| 2 | Pre-upgrade | Includes procedures that do not affect workability of the current OpenStack version such as running a QA cycle, verifying infrastructure, configuring monitoring of workloads and services. Also, during this stage, the backups are created and additional services, servers, and systems are installed to facilitate the upgrade process according to the plan. |
| 3 | Upgrade | During this stage, the actual upgrade takes place. |
| 3.1 | Control plane upgrade | During this stage, the control plane is being upgraded. It should not have an impact on the data plane, but there might be compatibility issues between the data plane and control plane of different versions. To minimize the control plane downtime, we recommend performing the quickest upgrade depth, which is the application level upgrade first. And, once full OpenStack upgrade is completed, perform the dist-upgrade or even release upgrade by removing one controller node from the cloud, upgrading it, and adding it back. |
| 3.2 | Data plane upgrade | During this stage, the servers that host the end-user data applications including the compute, storage, and gateway nodes are being upgraded. Depending on the upgrade requirements, any kind of upgrade depths can be applied. |
| 4 | Post upgrade | Includes procedures that will not affect workability, post upgrade testing activities, and cleanup. |
Warning
Before you perform the upgrade on a production environment, accomplish the procedure on a staging environment. If the staging environment does not exist, adapt the exact cluster model and launch it inside the cloud as a heat stack, which will act as a staging environment.