Performance considerations - adjusting LE runtime options

One way to try to improve the performance of batch jobs running under the Batch Command Server is to override Language Environment® (LE) runtime options in your JCL that runs the executable DTXCMDSV program. See the topic about overriding Language Environment (LE) runtime options in the IBM® Transformation Extender Command Server documentation.

IBM Transformation Extender for z/OS® is shipped with a copy of the CEEUOPT runtime options module linked into the IBM Transformation Extender executable module. This copy of CEEUOPT is included to ensure that known performance-degrading options cannot be included from the existing runtime environment.

The STORAGE initialization options cause the most notable performance degradation to IBM Transformation Extender. HEAPCHK can also adversely affect the performance of IBM Transformation Extender. HEAP initial size and increment and STACK initial size and increment might provide better IBM Transformation Extender performance if tuned for a specific customer environment or set of maps.

See the IBM z/OS Language Environment documentation for details about the CEEUOPT options and how to remove and replace the CEEUOPT CSECT. The CEEUOPT CSECT need only be included in the DTXCMDSV module.

The copy of CEEUOPT used in IBM Transformation Extender is coded as follows:

CEEUOPT  CSECT                                                           
CEEUOPT  AMODE ANY                                                       
CEEUOPT  RMODE ANY                                                       
         CEEXOPT HEAP=(1M,256K,ANY,FREE,8K,4K),                        X 
               STACK=(128K,128K,ANY,KEEP),                             X 
               ALL31=(ON),                                             X 
               STORAGE=(NONE,NONE,NONE,8K),                            X 
               HEAPPOOLS=(ON),                                         X 
               TERMTHDACT=(UADUMP)                                       
         END                                                             

The CEEUOPT is contained in the DTXCMDSV module in the runtime library.

To start tuning the CEEUOPT settings, you will need an IBM Transformation Extender map that does not perform well at your installation, and a representative sample of the data that the map processes. Start by turning on the RPTSTG option RPTSTG=(ON), and then running Command Server with your map or maps, and data.

The RPTSTG option will produce a report showing the maximum amount of storage used for the Language Environment STACK and HEAP. Use these as initial values when you reassemble and link-edit your new CEEUOPT. The goal is to minimize the amount of STACK and HEAP allocations as these have a significant effect on the performance of IBM Transformation Extender.