DatabaseActivityMonitor

The DatabaseActivityMonitor class is used to notify WinCC OA about the state of the connection between the backend and the database.

This class contains the following functions:

• setConnectionEstablishedCallback - This sets up a callback function that will be triggered when notifyActivity() is called, but only after notifyConnectionFailure() has been called first.
• setConnectionLostCallback - This sets up a callback function that will be triggered when notifyConnectionFailure() is called, but only after notifyActivity() has been called first.
• notifyActivity - This method triggers the onConnectionEstablished callback, but only if the most recent callback that was called was onConnectionLost. Use this method when there are no errors with the database connection. - Calls the onConnectionEstablished callback if the last called callback was onConnectionLost. Call this method if there are no database connection errors.
• notifyConnectionFailure - This method triggers the onConnectionLost callback, but only if the most recent callback that was called was onConnectionEstablished. Use this method whenever there are errors with the database connection.
• hasTimeoutExpired - Checks the timeout of the last update of the database connection state.
• resetTimeout - Resets the timeout of the last update of the database connection state.
• setNewTimeout - Sets the new value of timeout of the last update of the database connection state.

DatabaseActivityMonitor databaseActivityMonitor(activityMonitorTimeout);
databaseActivityMonitor.setConnectionEstablishedCallback([&]()
    {
        if (doExit)
        {
            return;
        }
        sendMonitoringUpdateForDatabaseConnectionState(configChannelHandler, DatabaseActivityMonitor::DatabaseConnectionState::Established);
        logger.logDebug("[Backend] Backend has established/restored connection with database");
    });

databaseActivityMonitor.setConnectionLostCallback([&]()
    {
        if (doExit)
        {
            return;
        }

        logger.logWarning("[Backend] The connection to the database has been lost.");
        sendMonitoringUpdateForDatabaseConnectionState(configChannelHandler, DatabaseActivityMonitor::DatabaseConnectionState::Lost);
    });

if(pingDatabase())
{
    databaseActivityMonitor.notifyActivity();
}
else
{
    databaseActivityMonitor.notifyConnectionFailure();
}