Updating all instances at once risks widespread failures. A phased release rolls out the new version to a small subset of instances first, so you can verify the update before it reaches all instances. If problems occur, only a fraction of instances are affected and you can stop the rollout.
Enterprise Distributed Application Service (EDAS) supports phased releases for applications deployed on Elastic Compute Service (ECS) clusters. You control how many batches the rollout uses and whether each batch starts automatically or requires manual approval.
How phased releases work
An ECS cluster contains one or more instance groups, each with multiple instances. When you configure a phased release, you can release the application in phases by instance group.
Prerequisites
Before you begin, make sure that you have:
An application deployed on an ECS cluster in EDAS
The deployment package (JAR or WAR) for the new version, either as a local file or a URL hosted on a service such as Object Storage Service (OSS)
Release an application in batches
Log on to the EDAS console.
In the left-side navigation pane, choose Application Management > Applications.
On the Applications page, configure the following filters in the top navigation bar:
Select a region.
Select a microservices namespace from the Microservices Namespace drop-down list.
From the Cluster Type drop-down list, select ECS Clusters.
Click the name of the application that you want to update.
On the Basic Information page, click Deploy in the upper-right corner.
On the Select Deployment Mode page, find the Regular Release (Single-batch/Multi-batch) section and click Start Deployment.
Configure the deployment package for the new version.
Parameter Description Deployment Method The method selected when the application was first deployed. This value cannot be changed. For example, if the application was first deployed with a JAR package, only JAR is available for subsequent updates. To roll back to an earlier version, select Historical Versions. For more information, see Roll back applications in ECS clusters. File Uploading Method How to provide the deployment package. The package type (JAR or WAR) matches the initial deployment. Upload JAR Package / Upload WAR Package: Click the upload area and select the file. JAR Package Address / WAR Package Address: Enter the URL of the package hosted on a cloud service such as OSS. Version A version identifier for this release. Enter a version number, or click Use Timestamp as Version Number to generate one automatically. Description The description of the new version. Configure the release policy.
NoteSelecting All Groups releases to all instances across all groups, split into batches based on the Batches per Group setting.
NoteAfter you configure the release policy, a deployment script is generated in the Generate Maven Plug-in Configuration section. If you use the toolkit-maven-plugin plug-in to automate phased releases, copy this script into your Maven configuration.
Parameter Description Group The instance group to update. If the application has only one group, select All Groups or Default Group (both are equivalent). The maximum number of instances is shown in parentheses next to All Groups. If the application has multiple groups, select the target group. Batches per Group The number of batches to split the release into. The minimum is 1 instance per batch. Default: 2 Batches. Increase the batch count for a more gradual rollout. Batch Mode How the next batch starts. Automatic: The next batch starts after the wait time elapses. Manual: You trigger each batch, which gives you time to verify the update between batches. Wait Time Before Next Batch The interval between batches, in minutes. Select a value from the drop-down list. Java Environment The Java runtime for the new version. Options: Open JDK 8, Open JDK 7, and Dragonwell 8. Click OK to start the release. The Change Details page opens, where you can monitor the progress of each batch. For more information, see View application changes.
Verify the result
After the release completes, confirm the update from two perspectives: the change record and the instance status.
Check the change record
On the application details page, click Change Records in the left-side navigation pane.
In the Change Status column, check the status of the release:
Success: The application is released.
Execute failed: The release encountered an error. Click View in the Actions column to see details and troubleshoot.
Check instance status
On the application details page, click Basic Information in the left-side navigation pane.
Click the Basic Information tab. In the Application Information section, verify that the Deployment Package field shows the latest package.
Click the Instance Information tab. Verify that the Running Status of each instance in the target group is Normal.