Oracle Audio Technologies B31679-01 manual Performing an online upgrade with replication, Overview

Performing an online upgrade with replication

In “Performing an offline upgrade” on page 97 we showed how to perform various maintenance operations on TimesTen data stores that require that all applications be stopped. This section describes how to use the TimesTen replication feature to perform online upgrades for applications that require continuous data availability. You can do an online upgrade when moving between major TimesTen releases. If moving to a patch release, you may instead perform an in-place or offline upgrade.

Normally, applications that require high availability of their data use TimesTen replication to keep at least one extra copy of their data stores up to date. An online upgrade works by keeping one these two copies available to the application while the other is being upgraded and is unavailable to the application. The procedures described in this section assume that you have a bi-directional replication scheme configured and running for two data stores, as described in the TimesTen to TimesTen Replication Guide.

Note: Replication functions across releases only if the data store of the more recent version of TimesTen was upgraded from a data store of the older version of TimesTen. A data store created in the more recent version of TimesTen is not guaranteed to replicate correctly with the older version. For example, replication between a data store created in the 5.1 version of TimesTen and a data store created in the 7.0 version of TimesTen is not supported. However, if one data store was created in the

5.1version, and the peer data store was created in the 5.1 version and then upgraded to the 7.0 version, replication between them is supported.

Note: For security reasons, replication is not normally allowed between TimesTen 7.0 and previous versions. In order to perform an online upgrade with replication, you must start the main TimesTen 7.0 daemon with the -insecure-backwards-compat option. See “Communicating with older versions of TimesTen” on page 71 of the Oracle TimesTen In-Memory Database Operations Guide for more information.

Overview

Upgrading a data store from an older TimesTen release to a newer release is performed by disconnecting all applications from one of two replicated copies of a data store, making a backup of the data store with ttMigrate from the older release, loading the backup into a newer

104 Oracle TimesTen In-Memory Database Installation Guide