Extended CSA storage (ECSA)

The CDC Replication Engine for Db2® for z/OS® uses the DB2® Instrumentation Facility Interface (IFI) to obtain copies of the changes made to database tables from the DB2 log.

The IFI requires that the application program (IBM® Data Replication for Db2 for z/OS) supply a storage buffer located in the z/OS ECSA with storage key 7. A buffer (approximately 72KB in size or 288KB in size if a DB2 Data Sharing Group is being used) is required for each active IFI connection. CDC Replication will maintain an active IFI connection for each subscription for which it is actively mirroring data. CDC Replication will also maintain one active IFI connection for the address space and one active IFI connection for the Log Cache, if it is configured. This may require a reassessment of the size of ECSA as configured using z/OS IPL parameters, and will require an IPL if the value configured needs to be changed.