Scheduling the REDO job

The REDO job must be scheduled immediately after IMS™ is started and before the system is opened up for processing.

Before you begin

The REDO job basically runs on the same IMS system that processes the installation of the resource update list. To customize which target IMS systems are processed by the REDO job, specify target IMS systems in the SYSIN control statement.

Procedure

The following steps describe a sample procedure for scheduling the REDO process:

Start the IMS control region.
Use IMS TCO (time-controlled operations) to start the REDO job immediately at IMS startup.
In order to use IMS TCO for a REDO job, register the REDO job with the IMS.JOBS data set that is used for the IMS /START REG command.
When writing a TCO script, note the following:
- Code the /START REG command for starting the REDO job at the top of the TCO script.
- Set an interval time between the REDO job startup and the subsequent TCO script startup. Specify an appropriate interval time for your system.
- In the subsequent script, include a command that activates IMS resources such as /STA DC or /STA REGION.
In the following example, the REDO job is registered with the IMS.JOBS data set as "IOHREDO". The example assumes that the /STA REG command for starting the REDO job was added to an existing TCO script. The next command will be invoked three minutes after the REDO job is started.
```
/STA REG IOHREDO.                                          
*TIME      DFSTXIT0            S                       ****
/STA DC                                                    
/OPN NODE XXXXXXX                                          
/OPN NODE YYYYYYY                                          
/STA REGION IMSMSG1                                        
/STA REGION IMSMSG2                                        
/BRO MASTER                                                            S
THREE MINUTES HAVE ELAPSED SINCE IOHREDO STARTED.                       
*TIME      DFSTXIT0      0003  S                       ****
```
For more information, see the topic "IMS time-controlled operations" in IMS Operations and Automation.

Important: In an IMS DBCTL environment, you must implement this function without using TCO because of an IMS restriction. For more information, see Restrictions for using the installation store/forward function.

What to do next

If the REDO job ends abnormally for some reason, fix the error and rerun the REDO job manually.