Install Extract Components on Db2 z/OS

The Oracle GoldenGate Db2 z/OS Extract uses SQL objects to access and read the Db2 log. These Oracle GoldenGate Db2 z/OS objects require a minimum hardware platform of zEC12, a minimum operating system release of 2.4, and a minimum Db2 release of 12.1. The components consist of executable load modules, SQL stored procedures and functions, and external programs called via the stored procedures. These components are:

External authorized programs include the following:
1. oggib001 – Initialization and utility program
2. oggrb001 – Log read program functionality
3. oggmt001 – Stand-alone program that monitors ECSA and 64-bit memory
4. oggjt001 – Setup program for the oggmt001 startup JCL run from oggib001 program
5. oggfr001 – Utility for use by a DBA under guidance from Oracle Support
SQL stored procedure and function templates are included in the SQL script zOS_OGG_Setup_Template.sql with the OGGINITB and OGGREADB SQL.
JCL procedure, oggtask.jcl

Note:

The external names for the SQL and JCL name values are the default, which you can edit and update. This process is discussed in the subsequent sections.

The Replication Process for Db2 z/OS Extract figure illustrates the replication process for the Db2 z/OS Extract and its mainframe components.

Figure 4-1 Replication Process for Db2 z/OS Extract

The process starts and runs as shown in the figure ablve, using the numbers 1 through 9. These steps are listed below:

Extract reads the parameters, including the JCL parameters, from the parameter file created during installation.
Extract reports the startup information and prepares to write the trail files.
ODBC is used to gather information from the Db2 database and start replication.
The OGGINITB SQL stored procedure starts to prepare the shared memory and to gather other data needed for replication.
The OGGIB001 external program called by the SQL stored procedure starts the memory monitor task using the OGGJT001 job setup program.
The OGGMT001 memory monitor task starts monitoring the ECSA and 64-bit shared memory.
The OGGREADB SQL Function calls the external program OGGRB001.
The OGGRB001 external program repeatedly calls the Db2 log read program to create a result set that returns 1 to many log record buffers to the Extract.
When a log record result set is complete, OGGRB001 ends after sending the result set to the Extract.

Extract repeats steps 7 to 9 until shut down or abnormal termination. If the memory task fails to start, OGGIB001 program returns a flag indicating there was a JCL error or setup issue and Extract begins to manage its memory. If the memory task starts properly, the memory task tests constantly changing fields in the 48-byte ECSA shared memory. These fields stop changing if the Extract terminates for any reason. At that point, the memory manager waits in case the Extract or network is slow and releases the memory before shutting down after a configured time limit.

To install the components needed for Oracle GoldenGate for Db2 z/OS Extract:

Ensure that a library (PDSE) exists on the Db2 z/OS system and ensure that an entry for it is made in the authorized library list. This library is the location where the Oracle GoldenGate external program objects will reside.
Ensure that an APF-authorized WLM procedure references the PDSE from the preceding step. Oracle recommends that NUMTCB value for the WLM environment be 10-40 for stored procedures. The NUMTCB value depends on the maximum number of Extracts that are running concurrently against the database and on how much throughput each Extract requires. If you want flexibility in setting NUMTCB, specify it in the startup JCL for the WLM, but not in the creation panel.
You can set up security for the WLM application environments and for creating stored procedures by completing the following:
1. (Optional) Specify which WLM-established address spaces can run stored procedures. If you do not complete this step, then any WLM-established address space can run stored procedures.
2. Grant users access to create procedures in specific WLM address spaces.
3. Grant user access to create procedures in specific schemas. Use the GRANT statement with the CREATIN option for the appropriate schema.
4. Grant user access to create packages for procedures in specific collections. Use the GRANT statement with the CREATE option for the appropriate collection.
5. Grant access to refresh the WLM environments to the appropriate people.
6. Add additional RACF authority to the appropriate people, allowing the WLM procedures to start the memory manager job.
Ensure the ID used to run the WLM startup JCL procedure has permission to use RRSAF. Each time one of the Db2 WLM address spaces starts, it uses RRSAF to attach to Db2. See the Db2 12 for z/OS Installation and Migration Guide.
In the Linux or UNIX installation of Oracle GoldenGate for Db2 z/OS, there is a ZIP file located in the Oracle Goldengate installation directory at lib/utl/zOSutils.zip, which contains a file calledzOSPrograms.zip. Unzip zOSPrograms.zip to zOSPrograms.tar and copy zOSPrograms.tar in binary mode to your Db2 z/OS system into an HFS directory.
On your Db2 z/OS system in USS or OMVS, change directories to the directory containing zOSPrograms.tar.
Restore the objects with the command: tar -xovf zOSPrograms.tar.
Copy the objects to the authorized PDSE. Use the cp –X ogg[irmj][abt][0-9]* “//’authorized_PDSE_name’” where authorized_PDSE_name is the name of the APF authorized PDSE, intended for the Oracle GoldenGate objects. Using this command installs the objects with the default names.

Note:

In this command, the copy target is double-quote forward-slash single-quote authorized PDSE name single-quote double quote. The -X is an uppercase capital X not a lowercase x.
Installing the scripts with different names allows you to conform with system protocols, or it allows you to run multiple versions of Oracle GoldenGate. To install the scripts with different names, creating a shell script that renames the programs before copying them to the PDSE is recommended. An example of the shell script is given in the following code snippet.
```
#!/bin/bash
# Copy new programs renaming them to version 21.12 names.
cp oggib001 oggi2112
cp oggrb001 oggr2112
cp oggmt001 oggm2112
cp oggjt001 oggj2112
cp -X oggi2112 “//’SYS4.WLMDSNA.AUTHLOAD’”
cp -X oggr2112 “//’SYS4.WLMDSNA.AUTHLOAD’”
cp -X oggm2112 “//’SYS4.WLMDSNA.AUTHLOAD’”
cp -X oggj2112 “//’SYS4.WLMDSNA.AUTHLOAD’”
```
You can run the script using chmod +x scriptname command. You can copy and reuse this script for new versions.
You must create the SQL procedures using your SQL tool of choice so that Oracle GoldenGate can call the Extract objects. The Oracle GoldenGate stored procedures should have permission granted to only those users that use them for replication.

An example SQL script template in the Oracle GoldenGate install directory contains the SQL statements to set up the stored procedure and function on the Db2 z/OS instance. The SQL scriptzOS_OGG_Setup_Template.sql contained in zOSutils.zip is for Db2 v12.1 and higher and can run from any SQL tool on any platform that can connect to your Db2 z/OS instance. This script must run on the Db2 instance that you use with your Extract. The script provided in the remote installation directory is in ASCII format. The same script is restored through zOSPrograms.tar on the Db2 z/OS system in EBCDIC format and is suitable for use through native Db2 z/OS tools such as SPUFI.

Edit the following line before running the scripts:
- Modify the WLM ENVIRONMENT line to use the correct name for the WLM environment that you will use for Oracle GoldenGate.

Note:

The oggifi0001 schema name is configurable using the TRANLOGOPTIONS REMOTESCHEMA schemaname Extract parameter. The procedure and function names, OGGINITB and OGGREADB, in the template are not configurable. You can rename each external name in the scripts and the PDSE if the script names and the PDSE object names match. Changing these names is part of the procedure that allows migration to new versions or if specific naming procedures must be adhered to on Db2 z/OS.

The following table contains a check list of components that you may wish to edit and/or update:

Table 4-2 List of Editable Components

Component	From	Where
`oggib001`	tar file	authorized PDSE
`oggrb001`	tar file	authorized PDSE
`oggmt001`	tar file	authorized PDSE & proc library
`oggjt001`	tar file	authorized PDSE & Extract parm
`oggpr001`	tar file	procedure library & Extract parm
proclib	MVS	add Extract parm if needed
step libraries	MVS	WLM and `oggpr001` procedure library
remoteschema		`zOS_OGG_Setup_Template.sql` and Extract parm
WLM name	MVS	`zOS_OGG_Setup_Template.sql`
external program		`zOS_OGG_Setup_Template.sql`

Note:

Remember to perform all these steps after every new patch installation.