Deployment Issues with WebLogic Server

The key issues with deployment involve consistency across clustered domains with multiple instances of WebLogic Server running the same application. More specifically, consistency means ensuring that all servers within the domain and/or cluster represent the same state of the application.

WebLogic Server addresses this issue by implementing a two-phase deployment model. Within the first phase, called the prepare phase, the application is copied across the domain/clusters and validated. Unless this phase is completed successfully, deployment is terminated. In the second phase, called the activate phase, the application is made available to clients. Within this two-phase model, the second phase is not implemented unless the first phase is implemented. The first phase is not implemented unless all servers within the domain are successfully prepared. This model ensures consistent deployment states across the domain.

Hot deployment (deploying or redeploying an application while the server is running) is also implemented in WebLogic Server. Hot deployment is desirable in situations in which WebLogic Server must remain active and changes or updates are required within an active application.