Sun Java System Application Server Enterprise Edition 8.1 2005Q2 Administration Guide

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## The Deployment Life Cycle

After installing the Application Server and starting a domain, you can deploy (install) J2EE applications and modules. During deployment and as the application is changed, an application or module can go through the following stages:

1. Initial Deployment

   Before deploying an application or module, start the domain.

   Deploy (install) an application or module to a specific stand-alone server instance or cluster. Because applications and modules are packaged in archive files, specify the archive file name during deployment. The default is to deploy to the default server instance `server`.

   If you deploy to server instances or clusters, the application or module exists in the domain’s central repository and is referenced by any clusters or server instances you deployed to as targets.

   You can also deploy to the domain using the `asadmin deploy` command, not the Admin Console. If you deploy the application or module only to the domain, it exists in the domain’s central repository, but no server instances or clusters reference it until you add references, as explained in The Deployment Life Cycle.

   Deployment is dynamic: you don’t need to restart the server instance after deploying application or module for applications to be available. If you do restart, all deployed applications and modules are still deployed and available.

2. Enabling or Disabling

   By default, a deployed application or module is enabled, which means that it is runnable and can be accessed by clients if it has been deployed to an accessible server instance or cluster. To prevent access, disable the application or module. A disabled application or module is not uninstalled from the domain and can be easily enabled after deployment.

3. Adding or Deleting Targets for a Deployed Application or Module

   Once deployed, the application or module exists in the central repository and can be referenced by a number of server instances and/or clusters. Initially, the server instances or clusters you deployed to as targets reference the application or module.

   To change which server instances and clusters reference an application or module after it is deployed, change an application or module’s targets using the Admin Console, or change the application references using the `asadmin` tool. Because the application itself is stored in the central repository, adding or deleting targets adds or deletes the same version of an application on different targets. However, an application deployed to more than one target can be enabled on one and disabled on another, so even if an application is referenced by a target, it is not available to users unless it is enabled on that target.

4. Redeployment

   To replace a deployed application or module, redeploy it. Redeploying automatically undeploys the previously deployed application or module and replaces it with the new one.

   When redeploying through the Admin Console, the redeployed application or module is deployed to the domain, and all stand-alone or clustered server instances that reference it automatically receive the new version if dynamic reconfiguration is enabled. If using the `asadmin deploy` command to redeploy, specify `domain` as the target.

   For production environments, use rolling upgrade, which upgrades application without interruption in service. For more information, see “About Rolling Upgrades.”

5. Undeployment

   To uninstall an application or module, undeploy it.

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