HP 3000 Manuals HP 3000 Manuals
Handling Communication Line Failures
When a communication line (DS line) problem occurs the Silhouette system
remains active on both the primary and secondary systems. The procedures
for recovering communication between systems is described below.
Losing One of Several Communication Lines
If there are multiple communication lines and one line shuts down, the
other lines will continue transmission. A warning message is issued to
the System Console to inform the Operator.
1. Determine why the communication line failed and attempt to remove
the cause.
2. Issue a >SYSTEM command specifying the configuration file for the
affected communication line.
3. Once the line has been restored, issue a >USE command to the
Manager Program (MP) giving the DS line device number or device
name. Silhouette then attempts to resume communications between
the systems.
Losing All Communication Lines
If all communication lines configured for Silhouette are lost, a warning
message is issued to the System Console to inform the Operator. Repeat
the DS line recovery procedure, described above, for each of the lines.
If the Communication Process (CP) determines that the number of records
not transmitted exceeds the high water mark, it informs the Silhouette
Operator that a tape needs to be mounted. Then:
1. Mount a tape on the tape drive.
2. Reply to the tape request at the System Console.
3. Log records are sent to tape starting with the first record not
previously transmitted.
4. Repeat the communication line recovery procedure for each of the
DS lines.
5. Once the CP transmits enough records to tape so that the total not
transmitted falls below the high water mark, the tape is released.