Chapter 2: Control Data Collection › Start the Data Collection Processes › Stop the Data Collection Processes

Stop the Data Collection Processes

At times, you will need to stop and restart the data collection processes. The data collection processes must be shut down prior to a scheduled system shutdown using the PSDC$SHUTDWN.COM file. The PSDC$SHUTDWN.COM file is created by the installation of the Performance Agent and placed in the SYS$MANAGER directory. Be sure that this file is invoked from the system shutdown command file.

To stop a specific data collection process, you must first be logged on to the node on which that process is running or use the SYSMAN Utility. To stop the primary CPD data collection process, which has the process name PSDC$DC_SERVER, enter the following command:

$ ADVISE COLLECT STOP/WAIT CPD

Stopping the primary data collection process causes all the alternate data collection processes to stop.

To stop any alternate data collection process, use a command similar to the following command:

$ ADVISE COLLECT STOP DB_DISKS

The CPD Performance Agent must execute a termination handler procedure to return some of its non-paged pool. To terminate, it must perform the following actions:

• Dissolve all pending links with other processes running on the system.
• Relinquish several vectors that it uses to measure performance.

There is a normal delay for the termination handler to complete. The result is a delay between the time you issued the command to stop the CPD Performance Agent and the time its process disappears. You can synchronize the command completion with the actual termination by using the /WAIT qualifier.