Application Edition Rollout in Websphere 8.5

In Websphere 8.5 we can install different edition of the same application.While installing application there is a text box to input the edition number and description.

Once you have installed your editions of application you can rollout the new one to replace the old application without any outage.

I have installed two editions of HelloWorld App deployed in a dynamic cluster.

The edition 1.1 is active now .And  we replace the application with old base edition with Application Edition Controller feature.

Select the Checkbox of application which you want to rollout and click Rollout button.

It will take you to next page where certain configuration is needed.

 Rollout strategy 

Use group rollout to replace editions on members of the target cluster in a group of one. Group rollout is the most typical choice, and is useful when the cluster contains four or more members. Alternatively, you can perform group rollout with a specified group size through scripting. For more information about group rollout, read about application edition management administrative tasks. When the new edition becomes available during group rollout, all requests are directed to the new edition.

Use atomic rollout to replace one edition with another on half of the cluster at a time. This rollout type serves all user requests with a consistent edition of the application. Because all user requests are served a consistent edition, your cluster runs at half capacity. If your cluster has four or more members, consider dividing up the cluster into smaller groups by performing a group rollout. Atomic mode is also used with a single server deployment target. In a single server deployment target, the actions that are carried out against the second half of the cluster are omitted. If you stop your deployment targets before you start atomic rollout, the deployment targets are started when the new edition replaces the active edition regardless of the reset strategy you choose. This procedure provides better availability to the requests that are serviced during the rollout period.

Reset Strategy

Soft reset will restart only the application .If no native libraries is used by your application soft reset is enough.

Hard reset will restart the application server so the native files as well  can be loaded if needed by your application.

Drainage Interval
   Drainage interval is the time to wait for the existing affinity requests to be served .If the requests ended before the drainage interval time ,websphere will not wait till that time it will proceed with application rollout.
If you want it to wait till the mentioned drainage interval you have to set a custome property
appedition.rollout.softreset.fulldrainageinterval to true

Now the base edition is active .The application will be started automatically.