About the Upgrade Process for Replicated Configurations

For replicated configurations where the image upgrade strategy is:

  • Auto: The upgrade process is automated and occurs immediately. Kubernetes takes no explicit action to terminate Pods as part of the upgrade process. Instead, the TimesTen Operator automatically terminates Pods in an orchestrated manner to perform the upgrade.

  • Manual: The upgrade process is manual. Neither Kubernetes nor the TimesTen Operator takes immediate action. You are responsible for initiating the upgrade.

Note:

The following actions occur during both an automated and a manual upgrade:

  • The standby is terminated first. It takes some time for the standby to come back up. When the standby comes back up, it is upgraded to the new release. During the upgrade of the standby, depending on your replication configuration, there may be disruption on the active database.

  • Next, the failover from the active to the standby occurs:

    • The active is terminated. It takes some time for the former active to come back up. When the active comes back up, it is upgraded to the new release.

    • The standby database is promoted to the active and the former active becomes the standby.

If you are using AWT cache groups, the standby is normally responsible for transmitting committed transactions from TimesTen to the Oracle Database. While the standby is being upgraded, the active takes on this responsibility. This may increase the load on the active. In addition, part of the upgrade process involves copying the database from the active to the standby. This also increases the workload on the active. These increases may temporarily reduce the performance of the active database.

For more information about how TimesTen performs an upgrade of an active standby pair of TimesTen databases, see Performing an Upgrade with Active Standby Pair Replication in the Oracle TimesTen In-Memory Database Installation, Migration, and Upgrade Guide.

Ensure you perform an upgrade at the appropriate time. We recommend that you do not perform upgrades at the busiest time of a production day. Applications may experience short outages and perhaps reduced performance as a result of the upgrade procedure.

There are examples later in the chapter that show you how to perform an automated and a manual upgrade for replicated TimesTenClassic objects. The examples are in the following sections: