Modifying BMP jobs to have the BMP handler add extra checkpoints

If the interval between checkpoints for your applications is long, use the IMS Online Reorganization Facility BMP handler to enable additional checkpoints.

About this task

The BMP handler adds checkpoint calls. You must manage application restarts using other methods.

Important: This task is effective only when BMP pauses are managed by IMS Online Reorganization Facility. If BMP pauses are managed by IMS Program Restart Facility, use the application management features provided by IMS Program Restart Facility.

Procedure

Specify the CHKPNTS DD statement in the JCL of the BMP.
You must adhere to the following syntax rules when you specify the CHKPNTS DD statement:
  • Enter only one parameter on each line.
  • The parameter must start within the first 20 positions.
  • To include a comment, type three or more blanks after the parameter, and then type the comment.
  • Do not use a comma at the end of a parameter.
  • If you specify multiple occurrences of the same parameter, only the last occurrence is used.

The CHKPNTS DD statement contains the following parameters:

PCB=nnn|name
nnn|name specifies the PCB to trigger the checkpoint. Specify a name or the PCB number, where 1 is the IOPCB. If you do not specify a value, PCB=2 is the default. If AIB calls are made, you must specify the PCB=name.
INTVL=nnn
nnn specifies the pause interval in seconds. If you do not specify a value, INTVL=30 is the default.
CALLTYPE=GU
This parameter specifies that a GU|GHU call triggers the pause test. This parameter is effective only when you specify CHKP=N.
POS=ROOT
This parameter specifies that whenever a root segment is reached, a pause test is triggered. This parameter is effective only when you specify CHKP=N.
APPLWAIT=Y
This parameter specifies that a TIMER wait of the application triggers the pause test. If the pause test is positive, the application is paused with a 3303 abend. Specify this parameter if the application does TIMER waits.
CHKP=(U | X | N)
This parameter specifies how the BMP handler adds a checkpoint. Specify this parameter with one of the following values if the application does not issue CHKP calls.
  • Specify U to interrupt at any IMS call for a specified PCB. If you specify CHKP=U, you must also specify the PCB parameter.
  • Specify X to interrupt at any IMS call for any of the PCBs.
  • Specify N to interrupt at the timing specified by either the CALLTYPE or POS parameter. If you specify CHKP=N, you must also specify the PCB parameter and either CALLTYPE or POS parameters.

Example

The following example checks PCB 4 for GN calls. When a root segment is returned, it determines if the 20-second interval has expired. If it has, IMS Online Reorganization Facility performs a pause test. If the BMP needs to be paused, a CHKP call is issued, the BMP is paused, and a 3303 abend is issued. The application restarts after the pause request has passed.

//CHKPNTS DD * 
  PCB=4 
  INTVL=20 
  POS=ROOT

The following example checks every 10 seconds for a pause request. If the application is in a TIMER wait, it pauses the application with a 3303 abend. The application restarts after the pause request has passed.

//CHKPNTS  DD  *
  INTVL=10
  APPLWAIT=Y