TRANSFER Installation and Management Guide

TMF Audited Files
The TRANSFER Environment
2–16 068837, Update 1 to 013198 Tandem Computers Incorporated
The command files for creating the database files are generated by the definition
programs, described in Section 5. The file creation parameters in the command files
set the AUDIT parameter for each database file as required by TRANSFER
components to ensure database consistency and to guarantee package delivery.
If you initialize the database files without changing any AUDIT parameters,
TRANSFER provides for delivery as follows:
Every package successfully submitted is delivered at most once within the
specified time window. If delivery cannot be made to a recipient for any reason,
TRANSFER notifies the sender of the failure to deliver the package.
If a TMF recovery (rollforward or autorollback) is performed and you run the
TSRBLD program after any multipoint failure, the files used by the scheduler are
rebuilt with all the submit and cancel operations recreated in those files. Section
11 of this manual describes the TSRBLD program.
After you have initialized the audited files, you should generate a TMF online dump
of the audited data files before starting the TRANSFER system. The TRANSFER
database and audit trail copies should be on different disk volumes.
Item Data File Auditing The Item Data file, which contains the actual data records that comprise items, can be
changed to a nonaudited file; however, complete integrity of the TRANSFER database
cannot be assured if the Item Data file is not audited. The implications of configuring
the Item Data file as a nonaudited file are as follows:
If a system failure occurs, the Item Data file might not be recoverable if its index
blocks are not in a consistent state.
If the Item Descriptor file is recovered after a failure, the Item Data file might have
data records for which the Item Descriptor file has no corresponding entry.
Similarly, the Item Descriptor file might have an entry for which no corresponding
records appear in the Item Data file. You can use the TCHECK program for
recovery in this situation. See Section 11 for information about TCHECK.
Session File Auditing The Session file, which contains the correspondent names for sessions currently in
progress, can be changed to a nonaudited file. The data in this file is more transient
than the data in any of the other TRANSFER database files; therefore, the audit trail for
the Session file can quickly become larger than the Session file.
You can control the amount of audit information in the following ways:
The Session file can be placed on an audited volume that has the audit trail
configured with the AUDITDUMP NONE parameter. TRANSFER can then
recover the Session file after a single point of failure. If a multipoint failure occurs,
data in the Session file might be lost; however, the loss is not significant because
all correspondents should start a new session after a multipoint failure. Audit
trails configured with the AUDITDUMP NONE parameter are purged when the
TMF backout process no longer needs the files; therefore, the audit trail will not be
significantly larger than the Session file.