Agent Startup and Shutdown Cycle Oracle Data Integrator External Dependencies

7-4 Oracle Fusion Middleware High Availability Guide start a fresh session by executing the scenario instead of restarting existing sessions that are in error state. By default, a session restarts from the last task that failed to execute typically a task in error or in waiting state. A session may need to be restarted in order to proceed with existing staging tables and avoid re-running long loading phases. In that case the user should take into consideration transaction management, which is KM specific. A general guideline is: If a crash occurs during a loading task, you can restart from the loading task that failed. If a crash occurs during an integration phase, restart from the first integration task, because integration into the target is within a transaction. This guideline applies only to one interface at a time. If several interfaces are chained and only the last one performs the commit, then they should all be restarted because the transaction runs over several interfaces. To restart from a specific task or step: 1. In Operator Navigator, navigate to this task or step, edit it and switch it to Waiting state. 2. Set all tasks and steps after this one in the Operator tree view to Waiting state.

3. Right-click the session and click Restart.

The session restarts from the first task in waiting state.

7.2.2 Agent Startup and Shutdown Cycle

Figure 7–2 shows the agent startup cycle. Figure 7–2 Oracle Data Integrator Agent Startup Cycle When the Oracle Data Integrator agent starts, it first reads its configuration, which includes master repository connection information. Then the agent connects to each of the work repositories attached to this master repository and removes stale sessions. Stale sessions are sessions that are incorrectly indicated in the work repository as running on this given agent. Stale sessions may result from an agent being stopped without being able to stop these sessions gracefully. As the agent restarts, it identifies the stale sessions and moves them to an error state. From that point, the agent can retrieve and compute the schedules available for it in each work repository. Once this phase is complete, the agent waits for incoming High Availability for Oracle Data Integrator 7-5 sessions requests to start their processing, and is also able to start sessions based on its schedules.

7.2.3 Oracle Data Integrator External Dependencies

Oracle Data Integrator depends on the Oracle Data Integrator master repository and work repository database schemas. If advanced features are being used, these other dependencies may exist: ■ Other Oracle Data Integrator agents: If the load balancing feature is configured and the agent needs to delegate the execution of sessions to its child agents. ■ If External Password Storage is enabled for this agents master repository, the agent depends on the credential store for retrieving the source and target data servers passwords to connect these data servers during session execution. ■ If External Authentication is enabled for this agents master repository, the run-time agents as well as Oracle Data Integrator Console depend on the Identity Store service that stores the Oracle Data Integrator user accounts. These components must be available for the Oracle Data Integrator system to start and run properly.

7.2.4 Oracle Data Integrator Startup and Shutdown Process