The governor daemon
The governor daemon collects information about applications that run against a database.
- The daemon checks whether its governor configuration file has changed or has not yet been read. If either condition is true, the daemon reads the rules in the file. This allows you to change the behavior of the governor daemon while it is running.
- The daemon requests snapshot information about resource use statistics for each application and agent that is working on the database.
- The daemon checks the statistics for each application against the rules in the governor configuration file. If a rule applies, the governor performs the specified action. The governor compares accumulated information with values that are defined in the configuration file. This means that if the configuration file is updated with new values that an application might have already breached, the rules concerning that breach are applied to the application during the next governor interval.
- The daemon writes a record in the governor log file for any action that it takes.
When the governor finishes its tasks, it sleeps for an interval that is specified in the configuration file. When that interval elapses, the governor wakes up and begins the task loop again.
If the governor encounters an error or stop signal, it performs cleanup processing before stopping. Using a list of applications whose priorities have been set, cleanup processing resets all application agent priorities. It then resets the priorities of any agents that are no longer working on an application. This ensures that agents do not remain running with non-default priorities after the governor ends. If an error occurs, the governor writes a message to the administration notification log, indicating that it ended abnormally.
The governor cannot be used to adjust agent priorities if the value of the agentpri database manager configuration parameter is not the system default.
Although the governor daemon is not a database application, and therefore does not maintain a connection to the database, it does have an instance attachment. Because it can issue snapshot requests, the governor daemon can detect when the database manager ends.