Fixed Issues › Fixes in r11.3 SP2 › Support for Running Windows Interactive Jobs in Session 0 › Session 0

Session 0

To overcome these limitations, the agent now supports running Windows interactive jobs in Session 0. To run Windows interactive jobs in Session 0, set the following parameter in the agentparm.txt file:

oscomponent.interactive.sessionzero=true

With this setting, an interactive job runs in Session 0. In Windows XP/Server 2003, the application window displays in the same way as user applications. In Windows Vista/Server 2008 and newer versions, the Interactive Services Detection service must be running. A dialog displays asking the user to switch to that application. Only a single pair of Windows Station/Desktop is available.

Running interactive jobs in Session 0 have the following disadvantages:

• Application has to be granted access to run in that session. Thus, you can potentially run into issues with the limited number of entries in the Window Station/Desktop Access Control Lists (ACL).
• In Windows XP/Server 2003, if the user logs on/off interactively, the ACL can be reset. If the user application tries to create more windows (require more access to the Window Station/Desktop), the application can fail.
• If the agent is restarted, it loses track of the logon sessions. Thus, the agent is unable to clean up adequately after applications complete their execution.
• Since there is only one Window Station/Desktop, applications can run out of User/GDI heap, thus limiting the number of concurrently running jobs. We recommend that you limit the number of concurrent running jobs to no more than 10 at a time.

Important! Microsoft has determined that using interactive programs in Session 0 is a security vulnerability.

http://msdn.microsoft.com/en-us/windows/hardware/gg463353.aspx

Starting with Windows Server 2008 R2, the Interactive Services Detection service is not started automatically. You must manually start the Interactive Services Detection service.

Starting with Windows Server 2012, the Interactive Services Detection service cannot be started without a change to the system registry. Microsoft warns that making this registry change has the potential to destabilize the operating system. This option may not be supported in the next release.

As long as Microsoft continues to provide backward compatibility, CA will continue to support this functionality even at the expense of system security and stability. CA urges all Workload Automation customers find alternatives to using Session 0 for their Workload Automation tasks.