Apps Cannot Be Displayed on the JobHistory Page When an Empty Part File Is Loaded

Question

If an application is executed in group mode and the corresponding part file in HDFS is empty, the app will not be displayed on the JobHistory home page.

Answer

When updating an app on the page, the JobHistory service checks the size of the part file in HDFS to determine whether to update the app information displayed on the home page. If the file has not been viewed before, the system compares its size with 0. If the size is greater than 0, the system reads the file.

In the case of grouping, if no job of the executed app is currently running, the part file will be empty. In this case, the JobHistory service will not read the file, and the app will not be displayed on the JobHistory page. However, if the size of the part file is updated later, JobHistory will display the app again.