Check your “scheduledTaskLogs” folder in files_dir. Are there records of recent files like “Usagestatisticsfileloadertask-*.log”? (The filename may be translated.) If so, these will detail what the process has been doing.
To process your logs into metics, you can’t just run php tools/RunScheduledTasks.php (at least at this time). You’ll need to specify one of the Usage Statistics File Loader tasks, such as: php tools/RunScheduledTasks.php plugins/generic/usageStats/scheduledTasksAutoStage.xml.