After a containerized application is created, you can adjust its settings, including:
The following parameters are mandatory:
Number of instances that the component has. Every instance is shipped as a container.
Number of instances that can be updated all at once.
The value is less than or equal to the total number of instances that the component has.
The default value is 1.
This parameter is useful to multi-instance applications. For example, if a component has 10 instances and the value of Instances for Batch Update is 1, then the 10 instances will be updated one by one.
Container image used by the application.
Any changes to a container image trigger a rolling update. A rolling update updates one instance at a time, rather than taking down the entire service at the same time.
The process for updating an instance is as follows: (1) CCE deletes an existing instance; (2) CCE creates a new instance from the new image and loads the information of the old instance to the new instance.
It is recommended that the source version and target version used for a rolling update belong to the same container image.
If you change the number of instances without updating the container image, the change is actually an instance scaling.
The CCE console then displays the updating process.
The amount of time required to complete the update depends on network speed and image size. If the update does not finish within three hours, the CCE stops the update and initiates a rollback.
You can manually stop the update and roll it back whenever needed. To stop the update, choose More > Stop on the Operation column of the corresponding application row.