ALM-18018 NodeManager Heap Memory Usage Exceeds the Threshold

Alarm Description

The system checks the heap memory usage of Yarn NodeManager every 30 seconds and compares the actual usage with the threshold. The alarm is generated when the heap memory usage of Yarn NodeManager exceeds the threshold.

The alarm is cleared when the heap memory usage is less than or equal to the threshold.

Alarm Attributes

Alarm ID	Alarm Severity	Alarm Type	Service Type	Auto Cleared
18018	Critical (default threshold is 95% of the maximum memory size.) Major (default threshold is 90% of maximum memory)	Quality of service	Yarn	Yes

Alarm ID

Alarm Severity

Alarm Type

Service Type

Auto Cleared

18018

Critical (default threshold is 95% of the maximum memory size.)

Major (default threshold is 90% of maximum memory)

Quality of service

Yarn

Yes

Alarm Parameters

Type	Parameter	Description
Location Information	Source	Specifies the cluster for which the alarm is generated.
	ServiceName	Specifies the service name for which the alarm is generated.
	RoleName	Specifies the role name for which the alarm is generated.
	HostName	Specifies the object (host ID) for which the alarm is generated.
Additional Information	Trigger Condition	Specifies the threshold triggering the alarm. If the current indicator value exceeds this threshold, the alarm is generated.

Impact on the System

When the heap memory usage of Yarn NodeManager is overhigh, the performance of Yarn task submission and operation is affected. In addition, a memory overflow may occur so that the Yarn service is unavailable.

Possible Causes

The heap memory of the Yarn NodeManager instance on the node is overused or the heap memory is inappropriately allocated. As a result, the usage exceeds the threshold.

Handling Procedure

Check the heap memory usage.

On the FusionInsight Manager portal, choose O&M > Alarm > Alarms > ALM-18018 NodeManager Heap Memory Usage Exceeds the Threshold > Location. Check the HostName of the instance for which the alarm is generated.
On the FusionInsight Manager portal, choose Cluster > Name of the desired cluster > Services > Yarn > Instance > NodeManager. Click the drop-down menu in the upper right corner of Chart, choose Customize > Resource > Percentage of Used Memory of the NodeManager to check the heap memory usage.
Check whether the used heap memory of NodeManager reaches 95% of the maximum heap memory specified for NodeManager.
- If yes, go to 4.
- If no, go to 6.
On the FusionInsight Manager portal, choose Cluster > Name of the desired cluster > Services > Yarn > Configurations > All Configurations > NodeManager > System. Increase the value of GC_OPTS parameter as required, click Save, and click OK, and restart the role instance.
The mapping between the number of NodeManager instances in a cluster and the memory size of NodeManager is as follows:
- If the number of NodeManager instances in the cluster reaches 100, the recommended JVM parameters for NodeManager instances are as follows: -Xms2G -Xmx4G -XX:NewSize=512M -XX:MaxNewSize=1G
- If the number of NodeManager instances in the cluster reaches 200, the recommended JVM parameters for NodeManager instances are as follows: -Xms4G -Xmx4G -XX:NewSize=512M -XX:MaxNewSize=1G
- If the number of NodeManager instances in the cluster reaches 500, the recommended JVM parameters for NodeManager instances are as follows: -Xms8G -Xmx8G -XX:NewSize=1G -XX:MaxNewSize=2G
Check whether the alarm is cleared.
- If yes, no further action is required.
- If no, go to 6.

Collect fault information.

On the FusionInsight Manager portal, choose O&M > Log > Download.
Select the following node in the required cluster from the Service.
- NodeAgent
- Yarn
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.
Contact the O&M engineers and send the collected logs.