fileLogger.go
func (f *FileLogger) fileMonitor() {
	defer func() {
		if err := recover(); err != nil {
			f.lg.Printf("FileLogger's FileMonitor() catch panic: %v\n", err)
		}
	}()

	//TODO  load logScan interval from config file
	logScan := DEFAULT_LOG_SCAN

	timer := time.NewTicker(time.Duration(logScan) * time.Second)
	for {
		select {
		case <-timer.C:
			f.fileCheck()
		}
	}
}
func (f *FileLogger) fileMonitor() {
	defer func() {
		if err := recover(); err != nil {
			f.lg.Printf("FileLogger's FileMonitor() catch panic: %v\n", err)
		}
	}()

	//TODO  load logScan interval from config file
	logScan := DEFAULT_LOG_SCAN

	timer := time.NewTicker(time.Duration(logScan) * time.Second)
	for {
		select {
		case <-timer.C:
			f.fileCheck()
		}
	}
}
// After some interval time, goto check the current fileLogger's size or date