gtpc1m22Transmission Control Protocol/Internet Protocol

How Network and Processor Failures Affect VIPAs

When an OSA-Express connection fails, it causes a swing to an alternate card on that processor, if one is defined and active. If a processor fails, you can move the movable VIPAs to another processor in the loosely coupled complex.

Swinging VIPAs to an Alternate OSA-Express Connection

If an OSA-Express connection fails and its alternate connection is active, the VIPAs automatically swing to the alternate connection on the same processor. This process, known as swinging VIPAs, also occurs when the alternate connection fails and the VIPAs return to their primary OSA-Express connection, if the connection is still active. You can swing VIPAs manually by entering the ZOSAE command with the SWING parameter specified. See TPF Operations for more information about the ZOSAE command.

Moving VIPAs from One Processor to Another

Movable VIPAs are moved from one processor to another by:

Processor Deactivation

The 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 once for each movable VIPA that meets any of the following conditions:

If UVIP is not coded, the VIPA is not moved.

For more information about the UVIP user exit, see TPF System Installation Support Reference.

The Operator and the ZVIPA Command

Enter the ZVIPA command with the MOVE parameter specified to transfer a movable VIPA to a different processor in the same loosely coupled TPF environment. To move a VIPA, you must define it as movable to the processor where you want it moved, as described in Defining VIPAs to an OSA-Express Connection.

Moving a VIPA by an Application Program

An application program can move a VIPA from one processor to another processor in the same loosely coupled TPF environment. To move a VIPA, you must define the VIPA as movable to the processor where you want it moved as described in Defining VIPAs to an OSA-Express Connection, and then use the VIPAC macro or the tpf_vipac C function to move the VIPA.

Workload Balancing Using Movable VIPAs

Workload balancing with movable VIPAs is useful for the following:

Enter the ZVIPA command with the SUMMARY parameter specified to display system and VIPA statistics and to determine the balance of network traffic in your TPF system. If you determine that your network is not balanced, you can move the movable VIPAs from an overloaded processor to a more available one. This is shown in the following example, where:

 CPU 
is the processor.

 PACKETS/SEC 
indicates the number of messages sent and received per second as determined by the traffic for the previous minute.

 CPU UTIL 
shows the immediate CPU utilization averaged over the I-streams for the designated processor.

+--------------------------------------------------------------------------------+
|User:   ZVIPA SUM                                                               |
|                                                                                |
|System: VIPA0003I 13.03.03 OSA IP ADDRESS SUMMARY DISPLAY BEGINS                |
|                                                                                |
|          CPU PACKETS/SEC CPU UTIL                                              |
|          --- ----------- --------                                              |
|           A         2300   76.9                                                |
|           B          290   12.1                                                |
|           C          650    1.2                                                |
|           E          122   21.2                                                |
|                                                                                |
|        END OF DISPLAY                                                          |
+--------------------------------------------------------------------------------+

The summary display shows that processor A is overloaded while processor C has a light load. To balance the network traffic, enter the ZVIPA command with the DISPLAY parameter specified to see IP activity on a per OSA IP address basis for the complex. This will help you determine which VIPAs on processor A should be moved to processor C. Before moving the VIPAs, ensure that they are defined on processor C. The following example displays OSA IP information, where:

 CPU 
is the processor that currently owns the IP address.

 IP 
is the IP address.

 TYPE 
is the type of IP address, where type is one of the following:

 MOVABLE 
specifies an IP address that is defined as a movable VIPA.

 STATIC 
specifies an IP address that is defined as a static VIPA.

 REAL 
specifies a real OSA IP address.

 MOVING TO CPU 
is the CPU to which the movable VIPA is in the process of moving.

 ACTIVE 
indicates whether the IP address is active.

 PACKETS/SEC 
indicates the number of messages sent and received per second as determined by the traffic for the previous minute.

+--------------------------------------------------------------------------------+
|User:   ZVIPA DISP ALL                                                          |
|                                                                                |
|System: VIPA0002I 13.03.04 OSA IP ADDRESS DISPLAY BEGINS                        |
|                                            MOVING                              |
|          CPU      IP             TYPE      TO CPU  ACTIVE  PACKETS/SEC         |
|          ---  ---------------  ---------   ------  ------  -----------         |
|           A     1.001.001.001  REAL                 YES              0         |
|           A     1.001.002.001  MOVABLE              YES            700         |
|           A     1.001.002.002  MOVABLE              YES            900         |
|           A     1.001.002.003  STATIC               YES            700         |
|           B     1.001.003.001  REAL                 YES              0         |
|           B     1.001.002.004  MOVABLE              YES            290         |
|           C     1.001.004.001  REAL                 YES              0         |
|           C     1.001.002.005  MOVABLE              YES            650         |
|           E     1.001.005.001  REAL                 YES              0         |
|           E     1.001.002.006  MOVABLE              YES            122         |
|                                                                                |
|        END OF DISPLAY                                                          |
+--------------------------------------------------------------------------------+

You can also view statistics for a specific OSA IP address or CPU by entering the ZVIPA command with those parameters specified instead of the ALL parameter.

To move VIPAs 1.1.2.2 from processor A to processor C, enter the ZVIPA command with the MOVE parameter specified, as shown in the following example:

+--------------------------------------------------------------------------------+
|User:   ZVIPA MOVE VIPA-1.1.2.2 CPU-C                                           |
|                                                                                |
|System: VIPA0004I 13.16.38 VIPA-1.001.002.002 MOVING FROM CPU-A TO CPU-C        |
|        VIPA0001I 13.16.38 VIPA-1.001.002.002 MOVED FROM CPU-A TO CPU-C         |
|                                                                                |
|        END OF DISPLAY                                                          |
+--------------------------------------------------------------------------------+

Enter the ZVIPA command with the SUMMARY parameter specified to see if the load is now balanced, as shown in the following example:

+--------------------------------------------------------------------------------+
|User:   ZVIPA SUM                                                               |
|                                                                                |
|System: VIPA0003I 13.26.29 OSA IP ADDRESS SUMMARY DISPLAY BEGINS                |
|                                                                                |
|          CPU PACKETS/SEC CPU UTIL                                              |
|          --- ----------- --------                                              |
|           A         1400    18.5                                               |
|           B          290    12.1                                               |
|           C         1550    10.2                                               |
|           E          122    21.2                                               |
|                                                                                |
|        END OF DISPLAY                                                          |
+--------------------------------------------------------------------------------+

For more information about the ZVIPA command, see TPF Operations.