Help Center/ MapReduce Service/ Developer Guide (Normal_Earlier Than 3.x)/ Flink Development Guide/ Commissioning a Flink Application/ Viewing the Running Result of a Flink Application
Updated on 2024-08-16 GMT+08:00
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Viewing the Running Result of a Flink Application

After a Flink application is run, you can view the running result or view the application running status on the Flink web UI.

Procedure

  • Viewing the running result of the Flink application

    To view the running result, you need to view the Stdout log of the TaskManager on the Flink web UI.

    If the running result is exported to a file or another path specified by the Flink application, you can obtain the running result data from the specified file or path. The following uses checkpoints, pipelines, and the JOIN between configuration tables and streams as examples.

  • Viewing checkpoint results and files
    • The results are stored in the taskmanager.out file of Flink. To view the results, log in to the Flink web UI, and click the out button under the task manager tag.
    • Two methods to view checkpoint files
      • If the checkpoint snapshot information is stored in HDFS, run the hdfs dfs -ls hdfs://hacluster/flink-checkpoint/ command to view the checkpoint files.
      • If the checkpoint snapshot information is stored in a local file, log in to each node to view the checkpoint files.
  • Viewing the Stream SQL Join results

    The results are stored in the taskmanager.out file of Flink. To view the results, log in to the Flink web UI, and click the out button under the task manager tag.

  • Viewing the running status of the Flink application on the Flink web UI

    The Flink web UI contains the Overview, Running Jobs, Completed Jobs, Task Managers, Job Manager, and Logout parts.

    On the web UI of YARN, locate the Flink application. Click ApplicationMaster in the last column of the application information. The Flink web UI is displayed.

    To view the results printed during application execution, locate the TaskManager and view the corresponding Stdout tag log information.

  • Viewing Flink logs to check application running status

    You can obtain Flink logs from the logs on either the Flink or YARN web UI.

    • On the Flink web UI, you can view logs of the TaskManagers and JobManager.
    • On the YARN web UI, you can view logs of the JobManager and GC.

      On the YARN web UI, locate the Flink application. Click the ID in the first column of the application information. On the displayed page, click Logs in the Logs column.