IBM SC34-7012-01 - Manual (Page 251)

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