How to prematurely fill up the IDMS log.

Document ID : KB000049379
Last Modified Date : 14/02/2018
Show Technical Document Details


There may be a need test IDMS log offload that requires prematurely filling up the IDMS log.


One option is to use DCMT WRITE STAT continuously to write the statistics that are being collected to the log. The effectiveness of this depends on the options enabled on the STATISTICS parameter on the SYSTEM statement and the size of the log. A UCFBATCH job or CLIST could be used to continuously execute
a number of DCMT WRITE STAT.

Another option is to force Task snaps to the log. First use DCMT D SNAPS to verify that the snaps are enabled. If not, enable them. A program that all IDMS users have is RHDCSNON which could be used to generate the snap. Use LOOK PROGRAM=RHDCSNON to note the entry point offset for this module.

For example:

IDMSLOOK  -  OPSYS=z/OS         Release 17.0 Service pack 1   tape GJH01
         was loaded From CDMSLIB DSN --> DIST.CAGJH0.PRODTGT.LOADLIB    
Entry Point Offset +68     -  Reentrant     -  AMODE 31  -  RMODE ANY   
        3,528 Bytes in Load Module RHDCSNON loaded at 3FE08E00          
                        Module    Offset   Date   Time                  
                       RHDCSNON   +0      080515  1706                  
3FE08E00 +0      D9C8C4C3 E2D5D6D5 F0F8F0F5 F1F51706 RHDCSNON080515..   
3FE08E10 +10     C3D6D7E8 D9C9C7C8 E3404DC3 5D40F2F0 COPYRIGHT (C) 20   
3FE08E20 +20     F0F740C3 C14B40C1 D3D340D9 C9C7C8E3 07 CA. ALL RIGHT   
3FE08E30 +30     E240D9C5 E2C5D9E5 C5C44B40 40404040 S RESERVED.        
3FE08E40 +40     40404040 40404040 40404040 40404040                    
                    SAME AS PREVIOUS LINE                               
3FE08E60 +60     C3C160C9 C4D4E240 18CF47F0 C0061871 CA-IDMS ...0{...   
3FE08E70 +70     4510C024 3FE08E80 3FE08E88 00000000 ..{..\...\.h....

The entry point offset is identified as +68. Take the address associated with offset +68, in this example it would be address 3FE08E68.

Based on this address use DCMT VME 3FE08E68 x'00'

The x'00' will create a 0c1 abend. Next execute RHDCSNON with task S. You may do this multiple times. To remove this 0c1 use command