Help Center/ MapReduce Service/ User Guide/ Alarm Reference (Applicable to MRS 3.x)/ ALM-18023 Number of Pending Yarn Tasks Exceeds the Threshold
Updated on 2024-04-11 GMT+08:00
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ALM-18023 Number of Pending Yarn Tasks Exceeds the Threshold

Alarm Description

The alarm module checks the number of pending applications in the Yarn root queue every 60 seconds. The alarm is generated when the number exceeds 60.

Alarm Attributes

Alarm ID

Alarm Severity

Auto Cleared

18023

Major

Yes

Alarm Parameters

Parameter

Description

Source

Specifies the cluster for which the alarm was generated.

QueueName

Specifies the queue for which the alarm was generated.

QueueMetric

Specifies the queue metric for which the alarm was generated.

Impact on the System

  • It takes long time to end an application.
  • A new application cannot run after submission.

Possible Causes

  • NodeManager node resources are insufficient.
  • The maximum resource capacity of the queue and the maximum AM resource percentage are too small.
  • The monitoring threshold is too small.

Handling Procedure

Check NodeManager resources.

  1. On FusionInsight Manager, choose Cluster > Name of the desired cluster > Services > Yarn > ResourceManager (Active) to access the ResourceManager web UI.
  2. Click Scheduler and check whether the root queue resources are used up in Application Queues.

    • If yes, go to 3.
    • If no, go to 4.

  3. Expand the capacity of the NodeManager instance of the Yarn service. After the capacity expansion, check whether the alarm is cleared.

    • If yes, no further action is required.
    • If no, go to 6.

Check the maximum queue resource capacity and the maximum AM resource percentage.

  1. Check whether the resources of the queue corresponding to the pending task are used up.

    • If yes, go to 5.
    • If no, go to 6.

  2. On FusionInsight Manager, choose Tenant Resources > Dynamic Resource Plan and add resources as required. Check whether the alarms are cleared.

    • If yes, no further action is required.
    • If no, go to 6.

Adjust the monitoring thresholds.

  1. On FusionInsight Manager, choose O&M > Alarm > Thresholds > Name of the desired cluster > Yarn > Applications > Pending Applications, and increase the thresholds as required.
  2. Check whether the alarm is cleared 5 minutes later.

    • If yes, no further action is required.
    • If no, go to 8.

Collect the fault information.

  1. On FusionInsight Manager, choose O&M. In the navigation pane on the left, choose Log > Download.
  2. Expand the Service drop-down list, and select Yarn for the target cluster.
  3. 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.
  4. Contact O&M personnel and provide the collected logs.

Alarm Clearance

This alarm is automatically cleared after the fault is rectified.

Related Information

None