Orderly termination

An orderly termination of the network is invoked by the IMS master terminal operator using the IMS /CHECKPOINT FREEZE, /CHECKPOINT PURGE, or /CHECKPOINT DUMPQ command with the QUIESCE parameter.

QUIESCE is a /CHECKPOINT parameter that initiates shutdown processing for a network. When QUIESCE is specified, IMS sends the VTAM® shutdown (SHUTD) command to all workstations and waits until all workstations have completed normal processing and returned the VTAM shutdown-complete (SHUTC) command.

When all workstations have indicated that shutdown is complete, IMS performs checkpoint processing and then issues the VTAM CLSDST macro instruction. CLSDST causes VTAM to send the UNBIND command to all workstations. This command releases the workstations from session with IMS. The controller prohibits any further data transmission from the workstations.

During shutdown processing (the time between the VTAM shutdown-complete and CLEAR commands), the system's workstations should be prepared for any IMS output that results from shutdown processing.

During the processing of an orderly termination, the IMS master terminal operator can terminate the network unconditionally rather than wait for the orderly termination processing to complete. This can be done by invoking an immediate termination.