Restarting the Component Services › Stop and Restart Data Aggregator

Stop and Restart Data Aggregator

Situations can arise in which you must stop and restart Data Aggregator. For example, the operating system of the Data Aggregator host requires an upgrade. Stop Data Aggregator, perform the actions that you want to take, and restart Data Aggregator. Data Aggregator then resumes processing.

During a planned Data Aggregator shutdown, all polled data that is received before Data Aggregator shuts down are sent to Data Repository. This polled data is preserved for reporting and other purposes.

Consider the following information about data loading, rollups, and event threshold processing when you plan to stop Data Aggregator:

• All data that has been received from Data Collector components for the current poll cycles is processed before Data Aggregator stops. The data is not lost.
• If the threshold event processing has started at the time of shutdown, the data processing that has been received from Data Collector components completes before Data Aggregator stops.
• Threshold event processing resumes when Data Aggregator restarts.
• If the rollup processing has started at the time of shutdown, rollup processing for the data that has been collected from the Data Collector hosts completes before Data Aggregator stops.
• Rollup processing resumes when Data Aggregator restarts.

Data Aggregator could shut down in an unplanned manner, such as when the computer where Data Aggregator is installed loses power. In this case, Data Aggregator stops abruptly. In this case, polled data and threshold event information can be lost. Data loading of queued data from the Data Collector hosts resumes when Data Aggregator restarts. Event threshold processing and rollup processing for queued data resumes when Data Aggregator restarts.

Follow these steps:

1. Log in to the computer where Data Aggregator is installed. Log in as the root user or a sudo user with access to a limited set of commands.

   Note: For more information about the sudo user, see the Data Aggregator Installation Guide.

2. Open a command prompt and do one of the following steps:
   1. If you are logged in as the root user, type the following command:

      service dadaemon stop
      

   2. If you are logged in as the sudo user, type the following command:

      sudo service dadaemon stop
      

   Polling continues on Data Collector if it is running and polling when Data Aggregator is stopped. Data Collector queues polled data for future delivery to Data Aggregator.

3. Relocate the computer, or perform any other administrative tasks.
4. Log in to the computer where Data Aggregator is installed. Log in as the root user or a sudo user with access to a limited set of commands.

   Note: If you installed Data Aggregator as the sudo user, you set up a sudo command alias for the /etc/init.d/dadaemon command. Use the sudo command to run the dadaemon start script. For more information about the sudo user, see the Data Aggregator Installation Guide.

5. Open a command prompt and type the following command:

   service dadaemon start
   

   Data Aggregator starts and synchronizes with CA Performance Center automatically.

When Data Aggregator starts, any queued, polled data on the Data Collector host are sent to Data Aggregator. The newest data is discarded if the queued data exceeds a disk space limit that is configured on the Data Collector system. As a result, there is a gap in the polled reporting data.