Db2 for z/OS

TwinCommit captures changes from Db2 for z/OS 12 and 13 by reading the log remotely through the Instrumentation Facility Interface (IFCID 306). It runs off the mainframe on Linux, so nothing is installed on z/OS beyond a DRDA connection and the right authorities.

Prerequisites

• DATA CAPTURE CHANGES on each replicated table:

  ALTER TABLE PAYROLL.EMPLOYEE DATA CAPTURE CHANGES;

• Primary key or unique index on each table.
• MONITOR2 privilege for the TwinCommit user, required to read the log through IFI:

  GRANT MONITOR2 TO TWINCMT;

• SELECT on the replicated tables and on the catalog (SYSIBM.SYSTABLES, SYSIBM.SYSCOLUMNS, SYSIBM.SYSKEYS).
• Archive log retention covering your longest expected outage.
• A DRDA location cataloged on the TwinCommit host.

Configuration

source:
  type: db2zos
  location: DSNLOC1
  host: zos.example.com
  port: 446
  user: ${ZOS_USER}
  password: ${ZOS_PASSWORD}
  ssid: DB2P

Note

TwinCommit reads only committed log data and uses compressed log records where available, which keeps the IFI read cost low. Ask your z/OS team to monitor the TwinCommit authorization ID during the first week.

Limitations

• LOB and XML columns must be excluded.
• Tables using EDITPROCs that change the row format need a decoding exit; contact support.
• Data-sharing groups are supported. Point location at the group, and TwinCommit merges member logs in LRSN order.