Falling back from IBM Db2 AI for z/OS 1.6.x

You can fall back your installation of IBM Db2 AI for z/OS 1.6.x to 1.6.0, provided that you followed the steps to back up your installation (see Backing up IBM Db2 AI for z/OS) before undertaking the migration.

Before you begin

Note: Falling back to a prior maintenance version does not back out connection and thread profiles, nor does it back out the actions that occurred outside of Db2ZAI, such as rebound statements.

Note: For the JCL jobs described in the steps below, use the sample JCL jobs from the Db2ZAI maintenance level you are restoring.

Procedure

To fall back from IBM Db2 AI for z/OS 1.6.x:

Stop ML and stop Db2ZAI:
- (Db2 DBA) Use the Db2ZAI user interface to stop ML on all target Db2 systems.
- (Db2ZAI admin) Stop the Db2ZAI server processes (run $DB2ZAI_HOME/scripts/db2zai_services_stop, or stop using JCL). See Stopping the Liberty and Node.js servers with JCL or Stopping the Liberty and Node.js servers with USS.
- Stop ML on all not-connected target Db2 systems, if you have any.
Restore Db2ZAI to the prior maintenance level (SMP/E restore).

Note: Before proceeding with steps 3 through 9, discuss with IBM Support whether it is necessary.

If you ran the update.sh script in the prior migration step, restore the Db2ZAI home directory.
Complete the initial customization of the JCL include variables for batch jobs:
1. Customize hlq.SCOYSAMP(COYIVMC). COYIVMC is included in multiple hlq.SCOYSAMP(COYIMCxx) jobs.
Run the batch jobs to fall back the metadata Db2. Customize and run each of these jobs:
1. Run the jobs hlq.SCOYSAMP(COYIMC00) and hlq.SCOYSAMP(COYIMC01), which will drop and create the metadata repository.
  Note: The version of COYIMC00 that you run needs to be at the current level of Db2ZAI. The version of COYIMC01 that you run needs to be at the level that you are falling back to.
2. Run the job hlq.SCOYSAMP(COYF060C), which will modify the metadata repository for the restored data.
3. Run the RESTORE script generated by COYF060A, &HLQBACKC.METADATA.RESTORE, add a JOB card, and then submit to restore the maintenance-level metadata.
Re-run the following grant JCL jobs for the various Db2ZAI meta users or Db2ZAI meta group:
1. Run the backed-up job hlq.SCOYSAMP(COYGMSID) to assign the Db2ZAI meta scheduler ID to the ID that was designated as the meta scheduler ID during the deployment of the Db2ZAI user interface.
2. Run the backed-up job hlq.SCOYSAMP(COYGMUSR) to assign a user to Db2ZAI metadata user role.
Note: Be sure to use the version of jobs COYGMSID and COYGMUSR from the fallback level you created, per Backing up IBM Db2 AI for z/OS.
Fall back the target Db2 pseudo-catalog objects to the prior maintenance level. Repeat these steps for each target Db2:
1. Complete the initial customization of JCL include variables for batch jobs by customizing the backed-up version of hlq.SCOYSAMP(COYIVPC). COYIVPC is included in multiple hlq.SCOYSAMP(COYIPCxx) jobs.
  Note: Be sure to use the version of the job COYIVPC from the fallback level you created, per Backing up IBM Db2 AI for z/OS.
2. Run the batch job COYIPC00 (this job is at the current level). COYIPC00 does the following:
  - Drops the following indexes if they were created for Db2ZAI:
    - SYSIBM.DSN_PROFILE_HISTORY_IX_ALL
    - SYSIBM.DSN_PROFILE_ATTRIBUTES_HISTORY_IX_ALL
    Note: The version of COYIPC00 that you run needs to be at the current level of Db2ZAI.
  - Drops the target catalog database (DSNMLDB1) on the target connection.
  - Drops all DSNML stored procedures and user defined functions (the metadata database name is defined in the job COYIVPC, the default is DSNML).
3. Fall back the target Db2 pseudo-catalog objects to the prior maintenance level. Repeat these steps for each target Db2:
  1. Run the jobs hlq.SCOYSAMP(COYIPC01), hlq.SCOYSAMP(COYIPC02), hlq.SCOYSAMP(COYIPC03), and hlq.SCOYSAMP(COYIPC04) which will create the target connection.
    Note: Be sure to use the version of jobs COYIPC01, COYIPC02, COYIPC03, and COYIPC04 from the fallback level you created, per Backing up IBM Db2 AI for z/OS.
    
    Note: You only need to run hlq.SCOYSAMP(COYIPC04) if your fallback target connection installation is at the APAR PH60101, PH61349, PH61372, PH61373, and PH62655 (August, 2024) level or above.
  2. Run the job hlq.SCOYSAMP(COYF060D), which will modify the pseudo-catalog objects for the restored data.
  3. Run the RESTORE script generated by COYF060B, &HLQBACKC.CATALOG.RESTORE, add a JOB card to &HLQBACKC.CATALOG.RESTORE, and submit to restore the maintenance level pseudo-catalog.
  4. Run the job hlq.SCOYSAMP(COYF060F), which will fall back the profiles created by Db2ZAI Distributed connection control.
Re-run the backed-up version of the following grant jobs for each Db2ZAI target connection. Repeat these steps for each target Db2:
1. Run the job hlq.SCOYSAMP(COYGPSID).
2. Run the job hlq.SCOYSAMP(COYGPDCC).
3. Run the job hlq.SCOYSAMP(COYGPDC2).
4. Run the job hlq.SCOYSAMP(COYGPSA).
5. Run the job hlq.SCOYSAMP(COYGPSA2).
6. Run the job hlq.SCOYSAMP(COYGPSQL).
7. Run the job hlq.SCOYSAMP(COYGPSQ2).
Note: The jobs mentioned in this step are from the hlq.SCOYSAMP dataset that you backed up, per Backing up IBM Db2 AI for z/OS.
If you have imported data connections, fall back the imported data connection objects to the prior maintenance level. Repeat these steps for each imported Db2:
1. Complete the initial customization of the JCL include variables for batch jobs by customizing the backed-up version of hlq.SCOYSAMP(COYIVIC). COYIVIC is included in the job hlq.SCOYSAMP(COYIIC01) jobs.
  Note: Be sure to use the version of the job COYIVIC from the fallback level you created, per Backing up IBM Db2 AI for z/OS.
2. Run the batch job COYIIC00 (this job is at the current level). COYIIC00 does the following:
  - Drops the database for the imported connection.
  - Drops the schema.GET_AKIRA_ACCTG_AGG_VIEW function for the imported connection (where schema is what you have defined).
  Note: The version of COYIIC00 that you run needs to be at the current level of Db2ZAI.
3. Fall back the imported Db2 connection objects to the prior maintenance level. Repeat these steps for each import ed Db2:
  1. Run the job hlq.SCOYSAMP(COYIIC01), which creates the imported connection.
    Note: Be sure to use the version of the job COYIIC01 from the fallback level you created, per Backing up IBM Db2 AI for z/OS.
  2. Run the job hlq.SCOYSAMP(COYF060H), which modifies the import connection objects for the restored data.
  3. Add a job card to the RESTORE script &HLQBACKC.CATALOG.RESTORE that is generated by COYF060G, and submit the script to restore the maintenance level of the imported connection objects.
4. Re-run the backed-up version of the following grant jobs for each Db2ZAI imported connection. Repeat these steps for each imported connection:
  1. Run the job hlq.SCOYSAMP(COYGIADM).
  2. Run the job hlq.SCOYSAMP(COYGIAD2).
  3. Run the job hlq.SCOYSAMP(COYGISA).
  Note: The jobs mentioned in this step are from the hlq.SCOYSAMP dataset that you backed up, per Backing up IBM Db2 AI for z/OS.
If you have not-connected target Db2 objects, fall back the not-connected target Db2 objects to the prior maintenance level. Repeat these steps for each not-connected Db2:
1. Complete the initial customization of JCL include variables for batch jobs by customizing the backed-up version of hlq.SCOYSAMP(COYIVRC). COYIVRC is included in multiple hlq.SCOYSAMP(COYIRCxx) jobs.
  Note: Be sure to use the version of the job COYIVRC from the fallback level you created, per Backing up IBM Db2 AI for z/OS.
2. Run the batch job COYIRC00 (this job is at the current level). COYIRC00 does the following:
  - Drops the database of the not-connected target Db2 instances.
  - Drops the routines of the not-connected target Db2 instances.
  Note: The version of COYIRC00 that you run needs to be at the current level of Db2ZAI.
3. Fall back the not-connected target Db2 objects to the prior maintenance level. Repeat these steps for each not-connected target Db2 instance:
  1. Run the jobs hlq.SCOYSAMP(COYIRC01) and hlq.SCOYSAMP(COYIRC02) which will create the not-connected target Db2.
    Note: Be sure to use the version of jobs COYIRC01 and COYIRC02 from the fallback level you created, per Backing up IBM Db2 AI for z/OS.
  2. Run the job hlq.SCOYSAMP(COYF060J), which modifies the not-connected target Db2 objects for the restored data.
  3. Add a job card to the RESTORE script generated by COYF060I, &HLQBACKC.CATALOG.RESTORE, and submit the script to restore the maintenance level of not-connected target Db2 objects.
4. Re-run the backed-up version of the following grant jobs for each Db2ZAI not-connected target Db2 instance. Repeat these steps for each not-connected target Db2 instance.
  1. Run the job hlq.SCOYSAMP(COYGRADM).
  2. Run the job hlq.SCOYSAMP(COYGRAD2).
  Note: The jobs mentioned in this step are from the hlq.SCOYSAMP dataset that you backed up, per Backing up IBM Db2 AI for z/OS.
(Db2ZAI administrator) Start the server processes at the maintenance level using the JCL PROC or from the USS script. See Starting the Liberty and Node.js servers with JCL or Starting the Liberty and Node.js servers with USS.
Restart ML on all target Db2 systems using the Db2ZAI user interface. Restart ML on all not-connected target Db2 systems, if you have any.