The IMS synchronous ECCR captures changes made by IMS transactions as they occur and passes the captured changes to the PowerExchange Logger. After the changes are logged, control is returned to the transaction and the changed data is available for extraction. IMS synchronous capture provides real-time changed data capture and near real-time extraction capability for changed data.

During the installation of IMS synchronous capture, you link PowerExchange code into the IMS RESLIB. The IMS synchronous ECCR uses this code to gain control during database OPEN processing to perform registration checks. Registration check processing communicates with the PowerExchange Agent to determine if the database being opened is registered for capture.

The IMS synchronous ECCR runs as separate subtasks in the IMS control region, IMS DBCTL region, or in DL/I and DBB batch regions. In addition to the modifications to the IMS RESLIB, you must also update the IMS region JCL. The PowerExchange CRG load library must be included in the STEPLIB for all IMS online and batch regions where capture is required. During the initialization of the IMS region, PowerExchange dynamically installs the IMS interface and initializes the IMS synchronous ECCR to capture changes.

The IMS synchronous ECCR captures changes made to IMS databases and logs those changes to the PowerExchange Logger. You must perform the following tasks before capturing changes for IMS databases:

After the IMS synchronous ECCR is active, you can activate new registrations by closing the database with the IMS DBR command and re-opening the database with the IMS START command. You can communicate with the ECCR by using the PowerExchange IMS external subsystem commands.