Help Center/ MapReduce Service/ User Guide/ MRS Cluster O&M/ MRS Cluster Alarm Handling Reference/ ALM-45591 ConfigNode Direct Memory Usage Exceeds the Threshold
Updated on 2024-09-23 GMT+08:00
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ALM-45591 ConfigNode Direct Memory Usage Exceeds the Threshold

Alarm Description

The system checks the direct memory usage of the ConfigNode process every 60 seconds. This alarm is generated when the direct memory usage of the ConfigNode exceeds the threshold for five consecutive times. That is, the direct memory configured for ConfigNode cannot meet service requirements. This alarm is cleared when the direct memory usage of ConfigNode is less than or equal to the threshold.

Alarm Attributes

Alarm ID

Alarm Severity

Auto Cleared

45591

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

Direct memory overflow may cause instance unavailability, and the ConfigNode process may be unavailable for read and write operations.

Possible Causes

The direct memory configured for the node is improper. As a result, the usage exceeds the threshold.

Handling Procedure

Check the direct memory configuration.

  1. Log in to FusionInsight Manager and choose O&M > Alarm > Alarms. In the real-time alarm list, click in front of this alarm and view the role name and instance IP address in Location.
  2. Choose Cluster > Services > IoTDB. Click Instance, click the ConfigNode corresponding to the IP address obtained in 1, and check whether ConfigNode Direct Memory Usage on the Dashboard tab page reaches the threshold specified for the ConfigNode process (90% of the maximum direct memory by default).

    If the chart is not displayed, click the drop-down list in the upper right corner of the chart area and choose Customize > Memory. In the dialog box that is displayed, select ConfigNode Direct Memory Usage and click OK.
    • If yes, go to 3.
    • If no, go to 5.

  3. On FusionInsight Manager, choose Cluster > Name of the desired cluster > Services > IoTDB. Click Configurations then All Configurations. Click ConfigNode and select System. Set -XX:MaxDirectMemorySize in GC_OPTS to a larger value as required and save the configuration.

    • You are advised to set -XX:MaxDirectMemorySize in GC_OPTS to twice the direct memory used by the ConfigNode process. (You can change the value based on the actual service scenario.)
    • To obtain the size of the direct memory used by the ConfigNode process, choose Customize > Memory > ConfigNode Direct Memory Resource Status.
    • If GC_OPTS does not contain the -XX:MaxDirectMemorySize parameter, add it.

  4. Restart the affected IoTDB service or instances and check whether the alarm is cleared.

    • If yes, no further action is required.
    • If no, go to 5.

    During the restart of the IoTDB service or instance, read and write requests are interrupted.

Collect fault information.

  1. On FusionInsight Manager, choose O&M > Log > Download.
  2. Expand the Service drop-down list, and select ConfigNode for the destination cluster.
  3. Expand the Hosts drop-down list. In the Select Host dialog box that is displayed, select the hosts to which the role belongs, and click OK.
  4. 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.
  5. Contact O&M personnel and provide the collected logs.

Alarm Clearance

This alarm is automatically cleared after the fault is rectified.

Related Information

None