Help Center/ MapReduce Service/ User Guide/ Alarm Reference (Applicable to MRS 3.x)/ ALM-24009 Flume Server Garbage Collection (GC) Time Exceeds the Threshold
Updated on 2024-04-11 GMT+08:00
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ALM-24009 Flume Server Garbage Collection (GC) Time Exceeds the Threshold

Alarm Description

The system checks the GC duration of the Flume process every 60 seconds. This alarm is generated when the GC duration of the Flume process exceeds the threshold (12 seconds by default) for five consecutive times. This alarm is cleared when the GC duration is less than the threshold.

Alarm Attributes

Alarm ID

Alarm Severity

Auto Cleared

24009

Major

Yes

Alarm Parameters

Parameter

Description

Source

Specifies the cluster for which the alarm was generated.

ServiceName

Specifies the service for which the alarm was generated.

RoleName

Specifies the role for which the alarm was generated.

HostName

Specifies the host for which the alarm was generated.

Trigger Condition

Specifies the threshold for triggering the alarm.

Impact on the System

Flume data transmission efficiency decreases.

Possible Causes

The heap memory of the Flume process is overused or inappropriately allocated, causing frequent occurrence of the GC process.

Handling Procedure

Check the GC duration.

  1. Log in to FusionInsight Manager and choose O&M. In the navigation pane on the left, choose Alarm > Alarms. On the page that is displayed, locate the row containing GC Duration Exceeds the Threshold, and view the Location information. Check the name of the host for which the alarm is generated.
  2. On FusionInsight Manager, choose Cluster > Name of the target cluster > Services > Flume. On the page that is displayed, click the Instance tab. On the displayed tab page, select the role corresponding to the host name for which the alarm is generated and select Customize from the drop-down list in the upper right corner of the chart area. Choose Agent and select Garbage Collection (GC) Duration of Flume. Then, click OK.

    Figure 1 Garbage Collection (GC) Duration of Flume

  3. Check whether the GC duration of the Flume process collected every minute exceeds the threshold (12 seconds by default).

    • If yes, go to 4.
    • If no, go to 6.

  4. On FusionInsight Manager, choose Cluster > Name of the desired cluster > Service > Flume > Configuration. On the page that is displayed, click All Configurations and choose Flume > System. Set -Xmx in the GC_OPTS parameter to a larger value based on site requirements and save the configuration.

    If this alarm is generated, the heap memory configured for the Flume server is insufficient for data transmission. You are advised to change the heap memory to: Channel capacity x Maximum size of a single data record x Number of channels. Note that the value of xmx cannot exceed the remaining memory of the node.

  5. Restart the affected services or instances and check whether the alarm is cleared.

    • If yes, no further action is required.
    • If no, go to 6.
      • During the restart, the Flume service is interrupted.
      • During the instance restart, if the failover mode of SinkGroup is configured and at least one instance is running properly, the Flume service is not interrupted. Otherwise, the Flume service is interrupted.

Collect 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 Flume for the target cluster.
  3. Click the edit icon 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