What do you recommend?

A customer claims that while redeploying a web application in the production system all their
customers are having to log in again. What do you recommend?

A.
Sessions can’t be preserved when redeploying applications. The customer needs to consider
redeployment during late nights when the traffic is low.

B.
Change the flag responsible for the development mode of their environment. In the production
mode, all sessions are preserved while redeploying application.

C.
Change Hotspot to JRockit. Sessions can’t be preserved on HotSpot when redeploying
application.

D.
Use flag -version when redeploying the application. This will switch on the Side By Side
deployment feature and preserve existing sessions.

E.
Open a service request with Oracle Support. This is unexpected behavior. Sessions are
preserved without any extra settings.

Explanation:
Restrictions on Production Redeployment Updates
WebLogic Server can host a maximum of two different versions of an application at one time.
Note:
* When you redeploy a new version of an application, you cannot change:
An application’s deployment targets
An application’s security model
A Web application’s persistent store settings
To change any of the above features, you must first undeploy the active version of the application.
Incorrect:
* (not A)
Production redeployment enables you to update and redeploy an application in a production
environment without stopping the application or otherwise interrupting the application’s availability
to clients. Production redeployment saves you the trouble of scheduling application downtime,
setting up redundant servers to host new application versions, manually managing client access to
multiple application versions, and manually retiring older versions of an application.
* (not C) Not dependant on whether the application is JRockit or Hotspot.
* (not E)
The production redeployment strategy is supported for:
Standalone Web Application (WAR) modules and enterprise applications (EARs) whose clients

access the application via a Web application (HTTP).
Enterprise applications that are accessed by inbound JMS messages from a global JMS
destination, or from inbound JCA requests.
All types of Web Services, including conversational and reliable Web Services, but not 8.x Web
Services.
Production redeployment is not supported for:
Standalone EJB or RAR modules. If you attempt to use production redeployment with such
modules, WebLogic Server rejects the redeployment request. To redeploy such modules, remove
their version identifiers and explicitly redeploy the modules.
Applications that use JTS drivers. For more information on JDBC application module limitations,
see JDBC Application Module Limitations in Configuring and Managing JDBC Data Sources for
Oracle WebLogic Server.
Applications that obtain JDBC data sources via the DriverManager API; in order to use production
redeployment, an application must instead use JNDI to look up data sources.
Applications that include EJB 1.1 container-managed persistence (CMP) EJBs. To use production
redeployment with applications that include CMP EJBs, use EJB 2.x CMP instead of EJB 1.1
CMP.
Reference: Reference; Deploying Applications to Oracle WebLogic Server 12c, Redeploying
Applications in a Production Environment