COBOL Manual for TNS/E Programs (H06.03+)

Procedure Division Verbs
HP COBOL Manual for TNS/E Programs—520347-003
9-240
STARTBACKUP
options
is either an integer numeric literal or an identifier that designates an integer
numeric data item. The value must be 0, 1, 2, or 3. The significance of options
is:
Usage Considerations:
•
When STARTBACKUP Statement Has No Effect
In the OSS environment, or in the Guardian environment when PARAM NONSTOP
OFF is active, the STARTBACKUP statement has no effect.
•
NONSTOP Compiler Directive
The STARTBACKUP statement can appear in a source program only when the
compiler finds the NONSTOP directive before it finds an Identification Division
header (see NONSTOP
).
0 The fault-tolerant facility is to read and process system messages, and the
primary process is to terminate abnormally if a trap condition occurs. If this
option is specified and the primary process is stopped (because of a
command interpreter STOP command or by a third process), the backup
process stops. The non-CRE environment run-time processes relevant
system messages, such as CPU-DOWN, as part of this activity. The
occurrence of a trap condition in the primary process causes it to fail (see
the explanation of ARMTRAP in the Guardian Programmer’s Guide.)
Additionally, if the backup process fails, the primary process automatically
starts a new backup process when it is possible to do so.
1 This option is the same as option 0 except that if the primary process stops,
the backup process takes over processing of the application.
2 This option is the same as option 1 except that if the primary process
encounters a trap condition, it enters the DEBUG procedure instead of
being terminated abnormally. (For an explanation of traps and the DEBUG
procedure, see the Guardian Programmer’s Guide.)
3 The primary process, rather than the fault-tolerant facility, reads the
$RECEIVE file and takes appropriate action for system messages. In
addition, if the primary process encounters a trap condition, it enters the
DEBUG procedure. When this option is in force and the backup process
fails, the primary process must re-execute the STARTBACKUP statement
to reestablish the backup. (This is considered an advanced option because
it requires direct calls to the operating system. If you use this option, see
the information on interprocess communication and checkpointing in the
Guardian Programmer’s Guide.)