In this blog entry various scenarios are described that outline the steps to migrate from an incremental update setup using CDC to an incremental update setup using Integrated Synchronization. This blog entry concludes the series of blog entries about Integrated Synchronization.
See the previous ones here:
Integrated Synchronization overview, architecture and setupComparison and coexistence of Integrated Synchronization and Change Data Capture for incremental updatesThis technote contains the content of all three blog entries:
Integrated Synchronization setup and migration scenarios for Incremental Update with Db2 Analytics Accelerator V7.5
Migration Scenarios
This blog entry describes the following scenarios to migrate to Integrated Synchronization from existing incremental update implementations using CDC:
- Accelerator V7: Migrating from CDC (without high-availability setup) to Integrated Synchronization
- Accelerator V7: Migrating from CDC (with high-availability setup) to Integrated Synchronization
- Accelerator V5 and V7: Migrating from a V5 accelerator with CDC to a V7 accelerator with Integrated Synchronization
Accelerator V7: Migrating from CDC (without high-availability setup) to Integrated Synchronization
In this scenario, a Db2 for z/OS V12 FL 500 system is paired to a Db2 Analytics Accelerator V7, and data is replicated to the accelerator using CDC. The Db2 system can either be a Db2 subsystem or a Db2 data sharing group. CDC is set up without high availability. The following picture shows this environment with sample values for CDC port number, DDF port number and IP addresses.
After the migration, the data is replicated to the accelerator using Integrated Synchronization. The following picture shows the migrated environment with sample values for the DDF secure port and IP addresses.
The setup and migration steps are the following (After it has been verified that all prerequisites are installed for Db2 for z/OS and that AT-TLS encryption is enabled):
- Setup phase: The following steps can be done while replication with CDC to the accelerator is still running:
- Define a secure network port for DDF (for example 12000)
- Set up AT-TLS encryption between the accelerator and Db2 DDF
- Prepare a user ID with defined access rights for Integrated Synchronization using RACF PassTicket or password authentication.
- Optionally this can be the same user ID that is already used in the incremental update setup with CDC and that was specified during incremental update enablement via the Db2 Analytics Accelerator Console. For Integrated Synchronization the user needs additional access rights as already described in chapter ‘Integrated Synchronization Architecture and Setup’.
- Migration phase: When executing the following steps, a time window must be defined carefully because no data will be replicated to the accelerator until the steps are complete. The time window must be at least as long as it will take to reload all the involved tables to the accelerator
- Stop replication for the Db2 system (for example by using administration client controls in Db2 Analytics Accelerator Studio or Data Server Manager)
- Disable replication for all tables (for example by using administration client controls)
- Logon to the Db2 Analytics Accelerator Console and disable CDC replication for the Db2 system
- Using the Db2 Analytics Accelerator Console, enable Integrated Synchronization replication for the Db2 system. Required input parameters are the Db2 IP address the accelerator uses to connect to Db2 for z/OS (for example 10.2.9.8), the secure DDF port number (for example 12000), the prepared user ID and the transferred public key of the signer certificate
- Start replication for the Db2 system (for example by using administration client controls)
- Enable tables for replication (for example by using administration client controls)
- Reload the tables (for example by using administration client controls)
- After a successful reload you have completed the migration to Integrated Synchronization. If it is no longer needed, you can now start removing the CDC capture agent component from the z/OS system.
Accelerator V7: Migrating from CDC (with high-availability setup) to Integrated Synchronization
In this scenario, a Db2 for z/OS V12 FL 500 data sharing group is paired to a Db2 Analytics Accelerator V7 and data is replicated to the accelerator using CDC. CDC is set up with high availability. This means one CDC Capture Agent is set up on one Db2 member and is replicating data to the V7 accelerator. The accelerator itself maintains a Db2 connection via DDF to the same Db2 member that the CDC Capture Agent is running on. A second CDC Capture Agent in hot standby mode is set up on another Db2 member. If the Db2 member of the active CDC Capture Agent goes down or the Capture Agent itself fails, then the second CDC Capture Agent on the other Db2 member takes over. The accelerator server then connects to Db2 for z/OS via DDF on that Db2 member. The following figure shows this environment with sample values for CDC port number, DDF port number and IP addresses.
After the migration, the data is replicated to the accelerator using Integrated Synchronization. At the time of writing a high-availability setup for Integrated Synchronization is not supported yet. If the Db2 member that runs the log data provider task goes down, then the preconfigured location alias name with SECPORT for Integrated Synchronization needs to be started on another Db2 member and replication must be restarted (for example by using administration client controls in Db2 Analytics Accelerator Studio or Data Server Manager). In the time between the failure of the Db2 member and the replication restart, no data is replicated.
The following picture shows the migrated environment with sample values for the DDF secure port and IP addresses.
The setup and migration steps are the following (after it has been verified that all prerequisites are installed for Db2 for z/OS and AT-TLS encryption):
- Setup phase: The following steps can be done while replication with CDC to the accelerator is still running:
- Define a location alias (for example DBINSYNCH) and a secure network port for DDF (for example 12011) to be used by Integrated Synchronization. Start the location alias only on one Db2 member
- In specific environments there might already be a SECPORT defined for other workloads, in the figure above this is SECPORT 12000. It is recommended to define a dedicated SECPORT for Integrated Synchronization (for example 12011)
- Set up AT-TLS encryption between the accelerator and the Db2 DDF
- Prepare a user ID with defined access rights for Integrated Synchronization using RACF PassTicket or password authentication.
- Optionally this can be the same user ID that is already used in the incremental update setup with CDC and that was specified during incremental update enablement from the Db2 Analytics Accelerator Console. For Integrated Synchronization the user needs additional access rights as already described in chapter ‘Integrated Synchronization Architecture and Setup’.
- Migration phase: When executing the following steps, a time window must be defined carefully because no data will be replicated to the accelerator until the steps are complete. The time window must be at least as long as it will take to reload all the involved tables to the accelerator
- Stop replication for the Db2 system (for example by using administration client controls from Db2 Analytics Accelerator Studio or from Data Server Manager)
- Disable all tables from replication (for example by using administration client controls)
- Logon to the Db2 Analytics Accelerator Console and disable CDC replication for the Db2 system
- Using the Db2 Analytics Accelerator Console, enable Integrated Synchronization replication for the Db2 system. Required input parameters are the Db2 DDVIPA (Db2 group IP) the accelerator uses to connect to Db2 z/OS (for example 10.2.9.8), the Db2 secure DDF port number (for example 12011) associated with the location alias that has been started on the Db2 member that will run the log data provider task, the prepared user ID and the transferred public key of the signer certificate
- Start replication for the Db2 system (for example by using administration client controls)
- Enable tables for replication (for example by using administration client controls)
- Reload the tables (for example by using administration client controls)
- After a successful reload you have completed the migration to Integrated Synchronization. If no longer needed you can now start removing the CDC capture agent component from the z/OS system.
Accelerator V5 and V7: Migrating from a V5 accelerator with CDC to a V7 accelerator with Integrated Synchronization
In this scenario, a Db2 for z/OS V12 FL 500 system is paired with a Db2 Analytics Accelerator V5 and data is replicated to the V5 accelerator using CDC. The Db2 system can either be a Db2 subsystem or Db2 data sharing group. In addition, a new V7 accelerator is set up in coexistence mode with a V5 accelerator; this means both accelerators are paired to the same Db2 system.
In this setup, it is highly recommended to start immediately with Integrated Synchronization on the V7 accelerator instead of starting with CDC first and migrating to Integrated Synchronization at a later time. This way, a replication downtime on the V7 accelerator will be avoided. A replication downtime would be required for migration from CDC to Integrated Synchronization on the V7 accelerator as described in the previous migration chapters because tables have to be reloaded after migrating to Integrated Synchronization.
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