Background
You may need to modify a deployed application to add or delete resources. This can be due to business growth or technology changes. Cloud Architect Design Tools (CADT) lets you modify the architecture of a deployed application to meet changing business needs in real time. When you deploy the modified application, only the added or deleted resources are processed. Existing resources in the application remain unaffected.
Example
This topic provides an example of how to change a simple monolithic website application into a high availability (HA) system architecture by adding an SLB and an ECS instance. The following figures show the architecture before and after the modification:
Procedure
Log on to the Cloud Architect Design Tools (CADT) console.
On the Applications > My Applications page, find the application whose architecture you want to modify and click View Architecture Diagram.
Add an SLB instance and an ECS instance to the application.
First, turn on edit mode. In the Product List on the left, add a private network SLB instance.
Right-click the ECS instance and click Copy to quickly create another instance with the same configuration.
Delete the connection line between the ECS instance and the EIP in the original application.
After you delete the line, a delete marker appears on it, as shown in the following figure. This marker indicates that the resource is pending deletion. The resource will be released during the next deployment.
Click Create Connection. Create connection lines from the EIP to the SLB instance, from the SLB instance to the ecs and ecs-1 instances, and from the ecs-1 instance to the RDS instance.
NoteThe blue plus sign (+) indicates that the resource is new. The resource will be created during the next deployment.
Switch back to default mode. Double-click the new resources and connection lines to configure them.
After you configure all the new resources, click the Save button in the upper-right corner.
After you modify the architecture, click Deploy Application.
First, run the Resource Validation check. After all items pass the validation, click Next: Price Checklist.
On the Price Checklist page, review the pricing information for the new resources. After you confirm the information, click Next: Confirm Order.
On the Confirm Order page, confirm the resource configurations and pricing information. Then, read the Cloud Architect Design Tools Terms of Service, select the check box to agree, and click Next: Pay and Create.
The deployment of the new resources begins.
Wait for the application deployment to complete.
After the application architecture is modified and deployed, the result is shown in the following figure. The new resources are deployed, and the architecture modification is complete.
Application version management
CADT supports version management for applications. You can view the evolution history of an application architecture and deploy previous versions.
On the CADT canvas, open the Resource Checklist and click Historical Versions.
On the version timeline, you can see the evolution history and versions of the application architecture.
Click a version number to view the application architecture diagram for that version.
To revert to a previous version, click the corresponding version number and then click Create Based on This Version. The historical version opens on the canvas.
Save the historical version as an application to perform subsequent operations.
