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Static IMS connectivity to DB2 via Subzero

This implementation procedure forces IMS to connect to specific DB2 subsystems via Subzero. You may want to use this implementation method in an environment used to validate Subzero functionality. The method is minimally invasive, but offers the least flexibility.

Warning

Note

This implementation procedure does not allow IMS to connect to a local DB2 subsystem using native DB2 interfaces. Even when the DB2 subsystem is on the same LPAR, it will connect via Subzero. Consequently, your IMS, DB2 and Subzero Subsystem Server address spaces are all on the same LPAR.

This implementation procedure does not support DB2 Group Attach Names. Your dependent region SSM member parameters must specify DB2 subsystem names; not DB2 Group Attach Names.

To create a static connection to DB2 via Subzero

  1. Change the IMS Configuration.

    1. Edit the DB2 external Subsystem member in your IMS PROCLIB.This is a member name of iiiissss where iiii is the IMS ID and ssss is the SSM suffix specified in your IMS startup. For example, IMSA with an SSM=DB2A would require a member of IMSADB2A in your IMS PROCLIB.

      Change the SSM member parameters from ESMT=DSNMIN10 to ESMT=BRDMIN10.

      Warning

      Example

      SST=DB2,SSN=T2HZ,LIT=SYS1,ESMT= DSNMIN10,REO=R,CRC=%

      is changed to :

      SST=DB2,SSN=T2HZ,LIT=SYS1,ESMT=BRDMIN10,REO=R,CRC=%

      Warning

      Note

      SSN can be DB2 source name in LGC options.

    2. Add the Subzero product library to the DFSESL DD statement in your IMS Control Region JCL.
    3. Add the Subzero product library to the DFSESL DD statement in your IMS Dependent Region JCL.
    Warning

    Note

    You do not need to remove any DB2 load libraries however, they are not needed for remote DB2 connectivity and can be removed unless there are application program requirements for them to be present (for example DSNTIAR to format messages).

  2. Implement the IMS configuration changes.You do not need to stop and restart IMS in order to implement your changes. You can simply stop and restart the subsystem definitions.
    1. Issue a  /STOP SUBSYS ALL command to IMS. This will stop the current connections to DB2.
    2. Issue a  /START SUBSYS ALL command to IMS. This will restart the current connection to DB2 using the new SSM parameters.

  3. Look for BRDM001 and/or BRD0150I messages indicating that your DB2 Subsystem connections are started and being redirected by Subzero:

    BMCBRD0150I Redirecting T2HZ to DB2 DEHZ on system SYSM
    BRDM001I IMS/TM T13P CONNECTED TO SUBSYSTEM T2HZ
  4. Restart your IMS dependent regions.

 

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Subsystem Optimizer 3.0