The default upgrade strategy is recreate for the Platform, and rolling upgrade for the EC:s.
For cases where blue/green or canary upgrade is required, there must be two deployments. For an example of a canary upgrade, see the httpDemo Helm chart in the Helm folder in the CI/CD pipeline example.
The CD pipeline is designed to create a new version of the configuration package running on a new EC. The old version is automatically removed. If the default rolling upgrade is overridden, the old version will still be running and processing all incoming data. Re-balancing the input load is not included in the example pipeline, as it is specific for each use case and customer.
Typical customizations to add:
The pipeline is valid for upgrade of the Usage Engine platform as well. Download the new images and start the pipeline. Currently the updating the Platform will result in a restart of all the PODs.