Recovery in an XRF complex

Use the Extended Recovery Facility (XRF) as an alternate IMS subsystem that monitors the log data of the active IMS subsystem and takes over the processing load of the active subsystem if it experiences a failure.

Everything about non-XRF recovery mechanisms is also true in an XRF complex, but with XRF, IMS can do more to reduce the time that data is unavailable to users after an abnormal event occurs.

You can specify conditions that trigger an automatic takeover, such as:

• A failure of the IMS control region
• A total failure of z/OS®
• A single central processor complex (CPC) failure
• An internal resource lock manager (IRLM) failure that requires an IMS STATUS exit routine
• A Virtual Telecommunications Access Method (VTAM®) failure that requires an IMS TPEND exit routine

You can also manually initiate an XRF takeover in a non-failure situation to introduce planned changes to your system with minimal disruption to users.