Customizing EXCI options

The EXCI options table, DFHXCOPT, allows you to specify a number of parameters for the EXCI. There is no suffixed version of this program, so the first DFHXCOPT table located in the STEPLIB concatenation is loaded. If you are using IPIC, you do not need to customize EXCI.

The following table shows the default parameters for the DFHXCOPT macro.
Figure 1. EXCI options table DFHXCOPT
          TIMEOUT=0,                   No timeout
          TRACE=OFF,                   Only Exception trace entries
          TRACESZE=16,                 16K trace table
          DURETRY=30,                  Retry SDUMPS for 30 seconds
          TRAP=OFF,                    DFHXCTRA - OFF
          GTF=OFF,                     GTF - OFF
          MSGCASE=MIXED,               Mixed case messages
          CICSSVC=0,                   EXCI will obtain CICS SVC number
          CONFDATA=SHOW,               Show user commarea data in trace
          SURROGCHK=YES                Perform surrogate-user check @P1C
For full details see the CICS Transaction Server for IBM® z/OS® External Interfaces GuideCICS Transaction Server for IBM z/OS External Interfaces Guide. The relevant parameters, shown in bold, are:
The default value OFF means that EXCI tracing is not required. Exception trace entries are always written to the internal trace table.
If you want to copy entries in the EXCI trace table to the generalized trace facility (GTF), specify GTF=ON.
This specifies the CICS® type 3 SVC number being used for MRO communication. EXCI must use the same SVC number that is used by the CICS MRO servers that are in the IBM z/OS image where the client program is running. If you do not specify a specific CICS SVC number, the external CICS interface determines the SVC in use for MRO by means of an IBM z/OS VERIFY command.

The default value zero means that EXCI will get the CICS SVC number from IBM z/OS. Specify 0 only when you are sure that at least one CICS server has logged on to DFHIRP during the life of the IBM z/OS IPL. If you use the default, and the external CICS interface requests the SVC from IBM z/OS, the request will fail if no CICS server has logged on to DFHIRP.

In other circumstances, specify the CICS SVC number, in the range 200–255, that is in use for CICS interregion communications. This must be the SVC number that is installed in the IBM z/OS image in which the client program is running (the local IBM z/OS).
Note: All CICS servers using MRO within the same IBM z/OS image must use the highest level of both DFHIRP and the CICS SVC, DFHCSVC. If your MRO CICSplex consists of CICS servers at different release levels, the DFHIRP and DFHCSVC installed in the LPA must be from highest release level of CICS within the CICSplex.
The default value SHOW allows user data to be traced. to hide it, set this value to HIDETC.
The default value YES means that a surrogate security check will be performed in the EXCI client address space if the flowed user ID is different from the user ID of the client address space. This occurs regardless of the CICS security settings. This means that if you flow a user ID in an EXCI request (including flowing a user ID with an External Call Interface [ECI] request using the CICS Transaction Gateway for IBM z/OS), you need either to add an RACF® surrogate profile, or disable surrogate security checks by setting this parameter to NO.
Note: If the CICS server has no security (SEC=NO), specify SURROGCHK=NO. For more information, see the CICS Transaction Server for IBM z/OS RACF Security GuideCICS Transaction Server for IBM z/OS RACF Security Guide.