Can you please clarify what you mean by " TezJobMonitor's monitorExecution log"? TezJobMonitor, based on a quick google seach, seems to be the API used by tez to keep track of the job execution. I don't think it exposes any logs for consumption.
In order to debug your job/application, you can always refer to the YARN app logs and Hive logs. Please refer to the following link for more info.