log\Dispatcher setFlushInterval()

How many messages should be logged before they are sent to targets. This method will set the value of yii\log\Logger::$flushInterval. Defaults to 1000, meaning the yii\log\Logger::flush() method will be invoked once every 1000 messages logged. Set this property to be 0 if you don't want to flush messages until the application terminates. This property mainly affects how much memory will be taken by the logged messages. A smaller value means less memory, but will increase the execution time due to the overhead of yii\log\Logger::flush().