gtpi1m5p | System Installation Support Reference |
The virtual IP address (VIPA) processor deactivation user exit, UVIP,
allows you to specify if a movable VIPA that is currently owned by a failing
processor should be moved to another processor in the complex. When a
processor is deactivated, UVIP is called one time for each movable VIPA that
meets any of the following conditions:
- The movable VIPA is owned by the deactivated processor and the specified
VIPA is not already in the process of being moved.
- The VIPA is owned by a deactivated processor and is moving to an inactive
processor.
- The VIPA is being moved to the deactivated processor.
If UVIP is not coded, the VIPA is not moved.
Input
The UVIP user exit requires the following values:
- R1
- A pointer to a zero-terminated list of 1-byte processor IDs to which the
VIPA could be moved. This list includes all active processors that have
the VIPA defined. A zero byte indicates the end of the list.
- R2
- A pointer to a 16-byte area containing the VIPA. For Internet
Protocol (IP) Version 4, the VIPA is in the last 4 bytes of the 16-byte
area.
Programming Considerations
- The VIPA will not handle Transmission Control Protocol/Internet Protocol
(TCP/IP) traffic until it is moved to another processor by using the UVIP user
exit or by using the ZVIPA command with the MOVE parameter specified.
If the VIPA is not moved, you can reactivate the deactivated processor to use
the VIPA again.
- The EBW and EBX work areas cannot be used in the UVIP user exit.
- Data levels D7 and D8 cannot be modified.
Return Values
R1 contains one of the following return codes:
- 0
- Do not move the VIPA to another processor.
- CPUID
- The low-order byte contains the CPU ID of the TPF processor to which the
VIPA will be moved.
If a zero is returned, the VIPA is not moved. Otherwise, the system
will move the movable VIPA to the active processor ID that is returned from
the supplied list. If the exit returns a processor ID that is not valid
or is inactive, the VIPA is not moved.
If the processor ID that you select for the UVIP user exit is not from the
supplied input list of valid CPU IDs, the VIPA is not moved.