Application management

Java™ Platform, Enterprise Edition (Java EE) applications and modules include an Extensible Markup Language (XML)-based deployment descriptor that specifies various Java EE artifacts that pertain to applications or modules. The Java EE artifacts include Enterprise JavaBeans (EJB) definitions, security role definitions, EJB references, resource references, and so on. These artifacts define various unresolved references that the application logic uses. The Java EE specification requires that these artifacts map to Java EE platform-specific information, such as that found in WebSphere® Application Server, during deployment of Java EE applications.

The application assembly tools that WebSphere Application Server supports, as well as the application management support that is provided with the product, facilitate collection of certain WebSphere Application Server information. The collected information is used to resolve references that are defined in various deployment descriptors in a Java EE application. This information is stored in the application EAR file in conjunction with the deployment descriptors. The following diagram shows the structure of an enterprise archive (EAR) file that is populated with deployment information that is specific to WebSphere Application Server.

The application management architecture provides a set of classes with which deployers can collect WebSphere Application Serverdeployment information. This information is also referred to as binding information, and is stored in the application EAR file. The deployer can install the EAR file into aWebSphere Application Serverconfiguration by using the AppManagement interface.

The application management support in WebSphere Application Server provides functions such as installing and uninstalling applications, editing binding information for installed applications, updating the entire application or part of the application, exporting the application, and so on. The com.ibm.websphere.management.application.AppManagement interface, which is exposed as a Java Management Extensions (JMX)-based AppManagement MBean in WebSphere Application Server, provides this functionality. Code that runs on the server or in a stand-alone administrative client program can access the interface. Access to the application management functions is also possible in the absence of WebSphere Application Server. This mode, known as local mode, is particularly useful for installing Java EE applications as part of product installation. For WebSphere Application Server Network Deployment, the AppManagement MBean is present in the deployment manager only, which facilitates centralized configuration and administration.

Application deployment in a WebSphere Application Server Network Deployment configuration

The following diagram explains application deployment for the WebSphere Application Server Network Deployment product:

1. The application EAR file that you install is stored in the master configuration repository of the deployment manager, with the application metadata.
2. The configuration synchronization operation replicates the application in the master repository into the repository of the target node.
3. The application EAR file is extracted to the installation destination of the target node at the end of the synchronization operation.
4. The WebSphere Application Server run time reads the application business logic such as EJB classes, servlets, and JavaServer Pages (JSP) from the installation destination while serving application client requests.
5. WebSphere Application Server reads the application metadata, such as deployment descriptors and WebSphere Application Server bindings during application startup from the configuration repository or the installation destination only, depending on the option that is specified during application installation.