ALM-14001 HDFS Disk Usage Exceeds the Threshold

Alarm Description

The system checks the HDFS disk usage every 30 seconds and compares the actual HDFS disk usage with the threshold. The HDFS disk usage metric has a default threshold. This alarm is generated when the HDFS disk usage exceeds the threshold.

You can choose O&M > Alarm > Thresholds > HDFS and change the threshold.

When Trigger Count is 1, this alarm is cleared when the value of the disk usage of HDFS cluster indicator is less than or equal to the threshold. When Trigger Count is greater than 1, this alarm is cleared when the value of the disk usage of HDFS cluster indicator is less than or equal to 90% of the threshold.

Alarm Attributes

Alarm Parameters

Impact on the System

Writing Hadoop distributed file system (HDFS) data is affected.

Possible Causes

The disk space configured for the HDFS cluster is insufficient.

Handling Procedure

Check the disk capacity and delete unnecessary files.

1. On the homepage of FusionInsight Manager, choose Cluster > Services > HDFS.
2. In the Chart area, click Real-time, and view the value of the monitoring item Percentage of HDFS Capacity to check whether the HDFS disk usage exceeds the threshold (80% by default). If the monitoring item is not displayed, click the drop-down list in the upper right corner of the Chart area, choose Customize > Disk, and select Percentage of HDFS Capacity.
   • If yes, go to Step 3.
   • If no, go to Step 11.

3. In the Basic Information area, click the NameNode(Active) of the failure NameService and the HDFS WebUI page is displayed.
   

   By default, the admin user does not have the permissions to manage other components. If the page cannot be opened or the displayed content is incomplete when you access the native UI of a component due to insufficient permissions, you can manually create a user with the permissions to manage that component.

4. On the HDFS web user interface (WebUI), click Datanodes tab. In the Block pool used column, view the disk usage of all DataNodes to check whether the disk usage of any DataNode exceeds the threshold.
   • If yes, go to Step 6.
   • If no, go to Step 11.
   Figure 1 Datanode Information
   

5. Log in to the node as user root where the cluster client is installed.
6. Run the following command to go to the client installation directory and complete authentication:

   cd /opt/client

   Load environment variables:

   source bigdata_env

   If Kerberos authentication is enabled for the cluster, run the following command to complete authentication as the cluster user that has the operation permissions for HDFS.

   You need to create related users on Manager in advance or contact the cluster administrator to obtain the users. For details, see Creating an MRS Cluster User.

   kinit hdfsuser

7. Run the following command to delete unnecessary HDFS files:
   1. Run the following command to check files or sub-directories in the corresponding folder:

      hdfs dfs -ls Folder name

   2. Run the following command to query the HDFS file directory size:

      hdfs dfs -ls HDFS file directory

      For example, if you run the above command to query the size of files or sub-directories in the /tmp folder, the following command output is returned, indicating that the /tmp/hadoop-yarn directory occupies 622,222,017 bytes:

      0          0          /tmp/.testHDFS
      207407339  622222017  /tmp/hadoop-yarn
      0          0          /tmp/hive
      0          0          /tmp/hive-scratch
      0          0          /tmp/logs
      ...

   3. Run the following command to delete confirmed unnecessary HDFS files:

      hdfs dfs -rm -r -f HDFS file or directory path

   

   Deleting files is a high-risk operation. Ensure that the files to be deleted are unnecessary files to prevent data loss.

8. Check whether the alarm is cleared.
   • If yes, no further action is required.
   • If no, go to Step 9.

Expand the system.

9. Expand the capacity of the cluster node where HDFS is deployed. For details, see Scaling Out an MRS Cluster.
10. Then, check whether the alarm is cleared.
    • If yes, no further action is required.
    • If no, go to Step 11.

Collect fault information.

11. On the FusionInsight Manager portal, choose O&M > Log > Download.
12. Select the following nodes in the required cluster from the Service:
    • ZooKeeper
    • HDFS

13. Click in the upper right corner, and set Start Date and End Date for log collection to 10 minutes ahead of and after the alarm generation time, respectively. Then, click Download.
14. Contact the O&M personnel and send the collected logs.

Alarm Clearance

After the fault is rectified, the system automatically clears this alarm.

Related Information

None