Help Center/ MapReduce Service/ User Guide/ MRS Cluster O&M/ MRS Cluster Alarm Handling Reference/ ALM-45288 TagSync Garbage Collection (GC) Time Exceeds the Threshold
Updated on 2024-09-23 GMT+08:00
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ALM-45288 TagSync Garbage Collection (GC) Time Exceeds the Threshold

Alarm Description

The system checks the GC duration of the TagSync process every 60 seconds. This alarm is generated when the GC duration of the TagSync 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

45288

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

TagSync responds slowly.

Possible Causes

The heap memory of the TagSync instance is overused or the heap memory is inappropriately allocated. As a result, GCs occur frequently.

Handling Procedure

Check the GC duration.

  1. On FusionInsight Manager, choose O&M > Alarm > Alarms > ALM-45288 TagSync Garbage Collection (GC) Time Exceeds the Threshold. Check the location information of the alarm and view the host name of the instance for which the alarm is generated.
  2. On FusionInsight Manager, choose Cluster > Services > Ranger > Instance. Select the role corresponding to the host name of the instance for which the alarm is generated and click the drop-down list in the upper right corner of the chart area. Choose Customize > GC > TagSync GC Duration. Click OK.

    Figure 1 TagSync GC duration

  3. Check whether the GC duration of the TagSync 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 > Services > Ranger > Instance > TagSync > Instance Configuration. Click All Configurations and choose TagSync > System. Increase the value of -Xmx in the GC_OPTS parameter based on the site requirements and save the configuration.

    If this alarm is generated, the heap memory configured for TagSync cannot meet the heap memory required by the TagSync process. You are advised to change the -Xmx value of GC_OPTS to twice that of the heap memory used by TagSync. You can change the value based on the actual service scenario. For details about how to check the TagSync heap memory usage, see 2.

  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 service restart, the service is interrupted. During the instance restart, the instance is unavailable, and the task on that instance fails to be executed.

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 Ranger 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