Help Center/ MapReduce Service/ User Guide/ Alarm Reference (Applicable to MRS 3.x)/ ALM-45281 UserSync Heap Memory Usage Exceeds the Threshold
Updated on 2024-04-11 GMT+08:00
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ALM-45281 UserSync Heap Memory Usage Exceeds the Threshold

Alarm Description

The system checks the heap memory usage of the UserSync service every 60 seconds. This alarm is generated when the system detects that the heap memory usage of the UserSync instance exceeds the threshold (95% of the maximum memory) for 10 consecutive times. This alarm is cleared when the heap memory usage is less than the threshold.

Alarm Attributes

Alarm ID

Alarm Severity

Auto Cleared

45281

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

Heap memory overflow may cause service breakdown.

Possible Causes

The heap memory usage of the UserSync instance is high or the heap memory is improperly allocated.

Handling Procedure

  1. On FusionInsight Manager, choose O&M > Alarm > Alarms > ALM-45281 UserSync Heap Memory Usage 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. Click the drop-down list in the upper right corner of the chart area and choose Customize > CPU and Memory > UserSync Heap Memory Usage. Click OK.

    Figure 1 UserSync heap memory usage

  3. Check whether the heap memory used by UserSync reaches the threshold (95% of the maximum heap memory by default).

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

  4. On FusionInsight Manager, choose Cluster > Services > Ranger > Instance > UserSync > Instance Configuration. Click All Configurations, and choose UserSync > 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 UserSync cannot meet the heap memory required by the UserSync process. You are advised to change the -Xmx value of GC_OPTS to twice that of the heap memory used by UserSync. You can change the value based on the actual service scenario. For details about how to check the UserSync 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.

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