Administering a Multisystem Environment › Linked Regions and Database Synchronization

Linked Regions and Database Synchronization

When the first region is created in your environment, two databases are downloaded and can be customized for your environment. Together, these two databases (the Automation Services database and the icon panel library) form the knowledge base.

To build a multisystem environment, you start by linking two regions, and then continue to link in any other regions. The linking process also synchronizes the knowledge bases of these regions.

Notes

• For linked focal point regions, synchronization is complete and the focal point knowledge bases are identical.
• For linked subordinates, synchronization is complete only to the extent of the relevant definitions in the knowledge base. For example, a subordinate knowledge base does not contain all system images. A subordinate knowledge base contains only those images that represent the environment the subordinate is managing.

When you link two regions, the local region in which you perform the link operation receives the knowledge base from the remote region. This remote region must be a focal point region. When you link a region into an existing multisystem environment, that region must be a stand-alone region.

Important! During the linking and synchronization process, the knowledge base in the local region is overwritten by the knowledge base from the remote focal region. If the local knowledge base has customized definitions that you want to retain, transmit these definitions to the remote knowledge base before you link the regions. Otherwise, the local knowledge base definitions are overwritten and lost.

Note: If the local region terminates during the linking and synchronization process, the local knowledge base can become corrupted and you cannot restart the region. Replace the corrupted knowledge base with your backup, restart the region, and resynchronize the knowledge base. For more information about backups, see the Reference Guide.

The following illustration shows the link and synchronization operation.

After you link the regions, the knowledge bases are synchronized and remain synchronized. If you change the knowledge base in one region, the changes are propagated to the other regions.

Background User Considerations

When you establish a region, a UAMS background system (BSYS) user ID for that region is automatically defined. The background user ID comprises the four‑byte region domain ID, followed by the characters BSYS. To establish fully-functioning communication links between regions, the BSYS user ID of each region must be duplicated in each linked region.

During a link and synchronize procedure, any required BSYS user IDs are defined automatically to UAMS, provided that the following conditions apply:

• You have UAMS maintenance authority on all the linked regions.
• The existing multisystem linked regions are active when the request is made.

If either of these conditions does not apply, then any required BSYS user IDs must be defined manually to UAMS. The simplest way to do this is to copy the BSYS user ID for the current region from the UAMS User Definition List and update the user ID. To access the UAMS maintenance functions, enter the /UAMS shortcut.

The link and synchronize request is rejected if both of the following apply:

• You do not have UAMS maintenance authority in the local or the remote region. (The user ID of the person who requests the link and synchronize procedure must be defined in the local and remote regions.)
• The required BSYS user IDs are not defined in the local or the remote region.

Important! If you use an external security system, you must manually define the BSYS user IDs of the remote systems to your external security system.

Transmit Records

You can transmit (that is, copy) knowledge base records from the local region to a remote region that is not linked to it.

You cannot transmit a system image to a region in which the image is currently loaded.

By specifying the appropriate transmission mode on the Remote System Identification panel, you can specify how to update the records in the remote region.

The following transmission modes are available:

• Replace (R) deletes any existing remote records, then transmits the local records.
• Overlay (O) replaces existing remote records with the same name, adds records that do not already exist, but does not delete any records in the remote knowledge base.
• Merge (M) adds records that do not already exist, but does not have any affect on existing records in the remote knowledge base.

Transmission Procedure

This diagram shows the transmit operation:

To transmit knowledge base records

1. Log on to the region from which you want to transmit the records.
2. Enter /MADMIN at the prompt.

   The Multi-System Support Menu appears.

3. Specify the type of system data that you want to transmit at the prompt and press Enter.

   A Remote System Identification panel appears.

4. Specify the ACB name (primary name) of the region to which you want to transmit records.

   If you specified the TI option, go to step 5. If you specified any other transmission options, go to Step 6.

5. Complete the System Name and Version fields.

   Note: For information about the fields, press F1 (Help)

6. Do one of the following:
   • If you want to replace a set of records or all elements of a component, enter REPLACE in the Transmission Mode field.
   • If you want to update a region by adding new records without updating existing records, enter MERGE in the Transmission Mode field.
   • If you want to update a region by adding new records and updating existing records, enter OVERLAY in the Transmission Mode field.
7. Specify the communication access methods to use for transmitting the selected records. You can enable any combination of the access methods.
8. Press F6 (Action) to select the specified option.

   If a selection list appears, go to step 9. If the Confirm Transmit panel appears, go to step 11.

9. Do one of the following:
   • If you selected option TC with a transmission mode of REPLACE, enter S beside the categories that you want to transmit.
   • If you selected option TC with a transmission mode of MERGE or OVERLAY, enter S beside the categories that you want to transmit.
     To select specific definitions in a category for transmission, enter L (List) beside the category to list the definitions, then enter S beside the definitions to transmit.
   • If you selected other transmission options with a transmission mode of MERGE or OVERLAY, press F4 (All) to transmit all definitions or enter S beside the definitions that you want to transmit.
10. Press F6 (Transmit).

    A Confirm Transmit panel appears.

11. Press Enter to confirm transmission.

    A status panel appears, showing the progress of the transmission.

    Note: If you choose to exit the status panel, you can check the status of the task by viewing the administration task log (MADMIN.L). Before you exit, note the task number for future reference.

Specify Multisystem Communications Access Methods

This procedure specifies the access methods that the region uses for communications. You can only enable a method if it is supported on your system.

To specify the communications access methods

1. Enter /PARMS at the prompt.

   The Customizer : Parameter Groups panel appears.

2. Enter U beside the MULTISYS parameter group.

   The MULTISYS - Multi-System Options panel appears.

3. Complete the following fields:

   VTAM?

   Specifies whether the region uses the VTAM access method.

   EPS?

   Specifies whether the region uses the EndPoint Services access method.

   TCP/IP?

   Specifies whether the region uses the TCP/IP access method.

   Link Establishment Timeout Period

   Specifies the time to wait for a link to be established.

   Default: 60 seconds

   Press F6 (Action).

   The communications access methods are activated.

Link and Synchronize Regions

Important! Do not add, update, or delete knowledge base records in any linked regions while synchronization is in progress. These changes may not be propagated to the new region. Before you perform synchronization, ensure that you back up the knowledge base.

To link and synchronize regions

1. Log on to the region to synchronize with the source (remote) region.

   The source region contains the knowledge base you want.

2. Enter /MADMIN at the prompt.

   The Multi-System Support Menu appears.

3. Select option SD.

   This establishes a link between the local region and another region, and updates the knowledge base of the current region.

   The Remote System Identification panel appears.

4. Complete the following fields:

   Primary Name

   Specifies the ACB name of the remote focal point region to which you want to link this region.

   Role in Multi-System Operation

   Specifies whether this region is a focal point region or a subordinate region. A focal point region must satisfy the following conditions:

   • The product sets in all focal point regions match.
   • At least one access method must be available.

   Subordinate System Image Name

   (Optional) If you specified subordinate, specify the name of the system image that is to be used by it.

   Important! Each subordinate is assigned a unique system image name, and it can use an image by that system image name only. When you build your environment for a subordinate, you must build the environment under the system image name specified during the linking operation.

   Subordinate regions are restricted to loading only system images with the name specified here. Different system image versions can be maintained under the system image name.

   Work Dataset

   (Optional) Specifies the VSAM data set to use to reduce the time for synchronization.

   The following fields specify the communication access methods to be used during synchronization. You can select any combination of the access methods; however, you can only select an access method if it is enabled in the MULTISYS parameter group.

   Use VTAM?

   (Optional) Specifies whether to use VTAM for communication.

   Use EPS?

   (Optional) Specifies whether to use EPS for communication.

   TCP/IP Host Name/Addr

   (Optional) Specifies the TCP/IP host name and address of the remote region.

   Port Number

   (Optional) Specifies the TCP/IP port number of the remote region.

5. Press F6 (Action) to initiate the linking process.

   A confirmation panel appears.

6. Press F6 (Confirm) to initiate region linking and knowledge base synchronization.

   A status panel appears.

   Note: Press F3 (Exit) to exit the status panel at any time without affecting the link and synchronize procedure. If you exit early, note the task number for later reference.

Monitor the Synchronization Procedure

While the synchronization procedure is in progress, the Synchronize Database Status panel is refreshed automatically every 10 seconds. This panel can be refreshed manually at any time by pressing the Enter key.

To check the status of the synchronization

1. From the Multi-System Support Menu, select option L to view the administration task log.
2. Enter S beside the appropriate entry from the log to view the status of the task.

The administration task log may contain up to 50 entries at any given time. Each task is allocated a sequential task number (between 1 and 50) as it commences. When the maximum task number is reached, allocation restarts from one and the oldest status records are overwritten. To delete a completed or failed task from the log, apply the D (Delete) action.

Knowledge Base Synchronization Maintenance

Automation Services maintains synchronization between linked knowledge bases by using a staging file.

When a knowledge base update occurs, information about the update is stored in the staging file as follows:

• For an update in a focal point region, a separate update record is written for each affected linked region.
• For an update in a subordinate region, a single update record is written for a linked focal point region.

A record stays in the staging file until the update is performed successfully in the destined region. If the region is inactive, the record stays in the staging file until the region is started.

Important! If the staging file becomes full, knowledge base synchronization cannot be maintained and the local region is unlinked automatically. A staging file can become full if a remote linked region remains inactive for an extended period of time. If an extended downtime is planned for a linked region, unlink the remote region before inactivation.