Administering Satellites Guide and Reference

Chapter 7. DB2 Data Replication

Partial Table-of-Contents

In the satellite environment, you can have group satellites synchronize on more than just the database definition. You can also have the satellites synchronize data with corporate databases.

For information that is supplementary to the information here, refer to the following Web site:

  www.software.ibm.com/data/db2/library/satellite

To accomplish data synchronization, you first have to set up and test a replication environment, independent of the satellite environment. Then, when you are satisfied with the results you obtain from the replication environment, you apply the replication definitions to the satellite environment. To apply the replication definitions to the satellite environment, you generalize these definitions to the satellites of a specific group by using the Generalize Replication Subscriptions window of the Satellite Administration Center. When you use the Generalize Replication Subscription window, the DB2 control server will either create or modify the group's setup batch, adding batch steps that create the tables on the satellite and the replication control server that are required for data replication. These tables are based on the source-target replication definitions that you generalized. The DB2 control server will also create or modify the update batch, adding a batch step to call the asnsat command, which, in turn, calls the Capture and Apply programs. Figure 4 provides an overview of the steps that you perform both to set up the replication environment, and to activate replication in the satellite environment.

Note:

Both the replication and the satellite environments use the term promote. This term, however, has a different meaning in each environment. In the replication environment, promote means to copy the replication definitions from a test to a production environment, and no satellites are involved. In the satellite environment, promote means to change the level of an application version from a test level (which is executed by test satellites) to a production level (which is executed by production satellites).

Figure 4. Overview of Setting up and Activating Replication for the Satellite Environment

Setting up Data Replication Steps Replication Sources Replication Targets Step 1. Set up the replication test environment. The replication test environment is outside of the satellite environment. Define the replication sources. To perform this task, you can use either the DJRA tools, or the Control Center. The replication source is expected to be either a test database or a test subsystem. The DB2 system that you use must be the same type of DB2 system that you intend to use as the production source system when replicating to satellites. Define the replication subscriptions. To perform this task, you can use either the DJRA tools, or the Control Center. The replication target is expected to be either a test database or a test subsystem. You must use a DB2 Universal Database system as the replication target. Step 2. Promote the replication test environment to a replication production environment. If you used a test database or test subsystem when you defined the replication source, use the DJRA tools to promote the source table definition to a production database. If you promoted the replication source, then you should promote a subscription to ensure that the replication control tables that record the source and target databases have been updated. Setting up the Satellite Environment Step 3. Generalize the subscription Use the Generalize Replication Subscription window of the Satellite Administration Center to perform this task. Test batch steps are written to the setup and update batches of the test level of the application version. These batch steps both set up and initialize data replication for the satellites. You can test the replication by having test satellites execute these batches. Step 4. Promote the test level of the application version. When you are satisified with the results that you obtain on the test satellites from the test level of the application version, promote the test level. When the production satellites synchronize, replication will be set up for them, and the satellites will replicate data.

Satellites can replicate data to and from all sources supported by the DB2 product family.

The sections that follow describe how to set up, configure, and start data replication in the satellite environment.

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