Chapter 22. IMS Logging

During IMS execution, all information that is necessary to restart the system in the event of hardware or software failure is recorded in a system log data set. The following critical system information is recorded in the logs:

• The receipt of an input message in the input queue

• The start of an MPP or BMP program

• The receipt of a message by the MPP for processing

• Before and after images of data base updates by the MPP or BMP program

• The insert of a message into the queue by the MPP

• The termination of an MPP or BMP program

• The successful receipt of an output message by the terminal

In This Chapter:

• "IMS System Checkpoints"

• "Database Recovery Control Facility (DBRC)" on page 368

• "IMS Log Components" on page 368