IBM SC34-7012-01 manual CICS VSAM Recovery QSAM copy, Remote Recovery Data Facility support

CICS VSAM Recovery QSAM copy

CICS VSAM Recovery (CICS VR) provides a QSAM copy function that can copy MVS log streams to a QSAM data set.

Copies of the QSAM data can be sent either electronically or physically to the remote site. On arrival at the remote site, you can use the MVS system logger import services to put the log records into an MVS system logger log stream. Alternatively, you can use CICS VR to perform forward recovery of a data set using the QSAM data directly.

Remote Recovery Data Facility support

The Remote Recovery Data Facility (RRDF) product from the E-Net Corporation supports the CICS log manager.

RRDF Version 2 Release 1 uses the disaster recovery services (for export and import of log streams) provided by the MVS system logger. RRDF connects to a log stream at the local site where the resource manager exit is specified, to register its interest. The recovery manager is given control whenever writes or deletes occur. Typically, writes are intercepted for transmission to the remote site. Delete requests are intercepted to prevent CICS from deleting system log records before RRDF has sent them to the remote site. RRDF at the remote site receives the transmitted log records, establishes an import connection to a log stream, and imports the log records.

CICS VR shadowing

CICS VR provides a data shadowing facility. Shadowing helps to reduce recovery time by applying forward recovery logs periodically at the remote site. See CICS VR documentation for a complete explanation.

CICS emergency restart considerations

It is important to consider the differences between CICS Transaction Server and earlier releases of CICS when planning for off-site recovery.

Indoubt and backout failure support

Support during emergency restarts for units-of-work that failed indoubt or failed during backout is provided by the CICS recovery manager.

This support is available at the remote site only if the system log is transmitted and the CICS regions at the remote site are running under CICS Transaction Server.

It is possible for system log records to be transmitted to the remote site for units-of-work that subsequently become indoubt-failed or backout-failed. The log records for failed units of work could be moved to the secondary log stream at the local site. However, resource managers such as RRDF are aware of such movements and act accordingly.

Remote site recovery for RLS-mode data sets

CICS provides support for remote site recovery where VSAM data sets are used in RLS mode at the primary site. Using this RLS support for remote recovery, you can switch over to the remote site without suffering indeterminate or unreported loss of data integrity.

Chapter 19. Disaster recovery 239