In canary release, you can specify a traffic adjustment rule and deploy a new version by using multiple policies. This is because the order of these two operations is not limited. The following table describes several available combination methods for canary release. You can evaluate the methods and choose an appropriate method based on your requirements.
|Deploy the new version > Specify a traffic adjustment rule||You can verify the maximum traffic for a canary group. Application deployment and canary rule configuration need to be joined only once.||Before the canary release rule takes effect, the inbound traffic of the instances for the application of the new version may not be canary traffic.|
|Deploy the earlier version > Specify a traffic adjustment rule > Upgrade to the new version||You can verify the maximum traffic for a canary group.||The smooth upgrade is also important. You need to check whether the upgrade of an application on relevant instances affects the requests that are being processed during the upgrade. Two application deployments are performed.|
|Specify a traffic adjustment rule > Deploy the new version||Application deployment and canary rule configuration need to be joined only once.||Before the application is deployed, canary traffic is downgraded and routed to the non-canary release environment. However, after the first batch of application instances of the new version is released, the instances may be affected by all the canary traffic.|
|Specify an invalid traffic adjustment rule > Deploy the new version > Specify a traffic adjustment rule||This method has the optimal controllability. The application instances that are newly deployed receive canary traffic only after the new valid canary release rule takes effect.||Two canary rule configurations are performed.|
- We recommend that you use the third method. This method is simple and can ensure that only canary traffic enters the canary release environment. However, only a few canary application instances exist in the early phase of the deployment, and application instances may be affected by heavy canary traffic after the canary release. Therefore, make sure that the traffic received by instances is in the expected range.
- End-to-end traffic adjustment is similar to single-application traffic adjustment. The difference is that specifying a traffic adjustment rule is changed to creating a canary release environment in end-to-end traffic adjustment.