Application deployment staging modes in weblogic

The deployment staging mode determines how deployment files are made available to target servers that must deploy an application or standalone module.
WebLogic Server provides three different options for staging files:

1. Stage mode
2. Nostage mode
3. External Stage mode

The following table describes the behavior and best practices for using the different deployment staging modes.
Application Deployment Staging Modes

Staging Mode	Behavior	When to Use
Stage	The Administration Server first copies the deployment unit source files to the staging directories of target servers. The target servers then deploy using their local copy of the deployment files.	1. Deploying small or moderate-sized applications to multiple WebLogic Server instances. 2. Deploying small or moderate-sized applications to a cluster.
NoStage	The Administration Server does not copy deployment unit files. Instead, all servers deploy using the same physical copy of the deployment files, which must be directly accessible by the Administration Server and target servers. With nostage deployments of exploded archive directories, WebLogic Server automatically detects changes to a deployment’s JSPs or Servlets and refreshes the deployment.	1. Deploying to a single-server domain. 2. Deploying to a cluster on a multi-homed machine. 3. Deploying very large applications to multiple targets or to a cluster where deployment files are available on a shared directory. 4. Deploying exploded archive directories that you want to periodically redeploy after changing content. 5. Deployments that require dynamic update of selected Deployment Descriptors via the Administration Console.
External Stage	The Administration Server does not copy deployment files. Instead, the Administrator must ensure that deployment files are distributed to the correct staging directory location before deployment With external stage deployments, the Administration Server requires a copy of the deployment files for validation purposes. Copies of the deployment files that reside in target servers’ staging directories are not validated before deployment.	1. Deployments where you want to manually control the distribution of deployment files to target servers. 2. Deploying to domains where third-party applications or scripts manage the copying of deployment files to the correct staging directories. 3. Deployments that do not require dynamic update of selected Deployment Descriptors via the Administration Console (not supported in external_stage mode). 4. Deployments that do not require partial redeployment of application components.

Most deployments use either stage or nostage modes, and the Administration Console automatically suggests the appropriate mode when you deploy an application or module.