gtps2m2aACF/SNA Data Communications Reference

Using the OSTG Program to Define SNA Resources

You can use the OSTG program to define all of the SNA resources to the TPF system. See TPF ACF/SNA Network Generation for more information about the OSTG program.

Once you define SNA resources using the OSTG program, you must load the resource definitions to the TPF system using the fresh load function or the dynamic load function. See Loading Resource Definitions by Performing a Fresh Load for more information about the fresh load function. See Loading Resource Definitions by Performing a Dynamic Load for more information about the dynamic load function.

Important Considerations

When you generate the TPF system, you must use the IODEV macro to define the symbolic device address (SDA) and system characteristics for each of the following SNA resources that you define to the TPF system using the OSTG program:

Otherwise, although you can create the resource definition for the SNA resource, you cannot activate it.

See TPF System Generation for more information about the IODEV macro.

Loading Resource Definitions by Performing a Fresh Load

The fresh load function replaces the current resource definitions in the TPF system with an entirely new set of resource definitions. That is, the resources that were previously defined to the TPF system using the OSTG program, the ZNDYN ADD command, and dynamic LU support are replaced with the new resource definitions during a fresh load.

The fresh load function also initializes all of the SNA control block structures in the TPF system, including the resource vector table (RVT), node control block (NCB) records, and the subarea address table (SAT). Therefore, when you perform a fresh load, you must first deactivate the network because any existing sessions are destroyed.

The fresh load process involves the following:

  1. When you enter the ZNOPL LOAD command and specify the FRESH parameter, the new resource definitions are loaded to the current resource resolution table (RRT) and the old resource definitions are copied to the alternate RRT. At this point, the new resource definitions are loaded to the TPF system; however, no processors in the TPF system are using the new definitions yet.
  2. As you perform an initial program load (IPL) on each processor in the TPF system, the SNA control block structures, including the RVT, NCB records, and SAT, are initialized on that processor. After the IPL has been completed on a processor, that processor is using the new (or current) resource definitions.

Important Considerations

To Perform a Fresh Load

Use the following procedure to perform a fresh load:

  1. Define the SNA resources using the OSTG program. See TPF ACF/SNA Network Generation for more information about the OSTG program.
  2. Load the pilot tape or general data set (GDS) that was created by the OSTG program to the TPF system.
  3. Deactivate the active resources in the TPF system. For more information about deactivating the resources in the TPF system, see Activating and Deactivating Resources.
  4. Enter the ZNOPL LOAD command and specify the FRESH parameter to load the new resource definitions to the TPF system.

    A message is displayed that prompts you to enter the ZRIPL command.

  5. Enter the ZRIPL command from each processor in the TPF system to perform an IPL and incorporate the new resource definitions.
    Note:
    You can enter the ZNOPL STATUS command to determine the processors that require an IPL to incorporate the new resource definitions.

Additional Information

See TPF Operations for more information about the following commands:

Forcing a Fresh Load during the Next IPL

Enter the ZNOPL BUILD command if you want to force a fresh load of the current resource definitions on 1, and only 1, processor during the next IPL.

The next time you perform an IPL on that processor, the SNA control block structures in the TPF system, including the resource vector table and the SAT, are initialized using the resource definitions in the current RRT.

Note:
The NCB records are not initialized during the build function.

See TPF Operations for more information about the ZNOPL BUILD command.

Loading Resource Definitions by Performing a Dynamic Load

The dynamic load function allows you to load new resource definitions to the TPF system without requiring you to perform an IPL or interrupt network communications. The dynamic load function does not initialize the SNA control block structures in the TPF system. It simply updates them with the new resource definitions. Therefore, you do not need to deactivate the network before you perform a dynamic load and the existing sessions are not destroyed.

In addition, the dynamic load function does not delete the resource definitions that were created using the ZNDYN ADD command or dynamic LU support. These resource definitions remain in the RVT after a dynamic load is performed.

The dynamic load process involves the following:

  1. When you enter the ZNOPL LOAD command and specify the DYNAMIC parameter, the new resource definitions are loaded to the alternate RRT.
  2. When you enter the ZNOPL UPDATE command, the alternate RRT becomes the current RRT, and the current RRT becomes the alternate RRT. At this point, the new resource definitions are loaded to the TPF system; however, no processors in the TPF system are using the new definitions yet.
  3. As you enter the ZNOPL MERGE command on each processor in the TPF system, the RVT and its related tables are updated on that processor with the new resource definitions. After the online merge function has been completed on a processor, that processor is now using the new (or current) resource definitions.

Restrictions

To Perform a Dynamic Load

Use the following procedure to perform a dynamic load:

  1. Define the SNA resources using the OSTG program. See TPF ACF/SNA Network Generation for more information about the OSTG program.
  2. Load the pilot tape or GDS that was created by the OSTG program to the TPF system.
  3. Enter the ZNOPL LOAD command and specify the DYNAMIC parameter to load the new resource definitions to the alternate RRT.

    A message is displayed that prompts you to enter the ZNOPL UPDATE command.

  4. Enter the ZNOPL UPDATE command from one processor in the complex to switch the current and alternate RRT definitions.

    A message is displayed that prompts you to enter the ZNOPL MERGE command.

  5. Enter the ZNOPL MERGE command from each processor in the TPF system to update the RVT with the new resource definitions.
    Note:
    You can enter the ZNOPL STATUS command to determine the processors where you must enter the ZNOPL MERGE command to incorporate the new resource definitions.

Additional Information

Falling Back to the Old Resource Definitions

After you perform a dynamic load, you can use the fallback function to reload to the TPF system the old resource definitions that were saved in the alternate RRT, if necessary.

Note:
You cannot fall back to the old resource definitions after you perform a fresh load. Instead, you must reload those resource definitions by entering the ZNOPL LOAD command.

When you use the fallback function, you can specify whether you want to reload the old resource definitions using the dynamic load function or the fresh load function.

To Fall Back using the Dynamic Load Function

You can use the dynamic load function to fall back to the old resource definitions without interrupting network communications or destroying existing sessions.

Use the following procedure to fall back to the old resource definitions using the dynamic load function:

  1. Enter the ZNOPL FALLBACK command to reload the old resource definitions from the alternate RRT to the current RRT.

    A message is displayed that prompts you to enter the ZNOPL MERGE command.

  2. Enter the ZNOPL MERGE command from each processor in the TPF system to update the RVT with the old resource definitions.
    Note:
    You can enter the ZNOPL STATUS command to determine the processors where you must enter the ZNOPL MERGE command to incorporate the old resource definitions.

To Fall Back using the Fresh Load Function

If you cannot fall back to the old resource definitions using the dynamic load function, you can fall back to the old resource definitions using the fresh load function.

Use the following procedure to fall back to the old resource definitions using the fresh load function:

  1. Deactivate the active resources in the TPF system. For more information about deactivating resources in the TPF system, see Activating and Deactivating Resources.
  2. Enter the ZNOPL FALLBACK command and specify the FRESH parameter to reload the old resource definitions from the alternate RRT to the current RRT.

    A message is displayed that prompts you to enter the ZRIPL command.

  3. Enter the ZRIPL command from each processor in the TPF system to perform an IPL and incorporate the old resource definitions.
    Note:
    You can enter the ZNOPL STATUS command to determine the processors that require an IPL to pick up the old resource definitions.

Additional Information

Displaying Status Information about the Load Functions

You can use the ZNOPL STATUS command to display the following information about the RRT, SNA resource definitions, and load functions:

See TPF Operations for more information about the ZNOPL STATUS command.