Description

The system checks the heap memory usage of MapReduce JobHistoryServer every 30 seconds and compares the actual usage with the threshold. The alarm is generated when the heap memory usage of MapReduce JobHistoryServer exceeds the threshold (80% of the maximum memory by default).

To change the threshold, choose System > Threshold Configuration > Service > MapReduce. The alarm is cleared when the heap memory usage is less than or equal to the threshold.

Attribute

Alarm ID	Alarm Severity	Automatically Cleared
18009	Major	Yes

Parameters

Parameter	Description
ServiceName	Specifies the service for which the alarm is generated.
RoleName	Specifies the role for which the alarm is generated.
HostName	Specifies the host for which the alarm is generated.
Trigger Condition	Specifies the threshold for triggering the alarm.

Impact on the System

When the heap memory usage of MapReduce JobHistoryServer is overhigh, the performance of MapReduce log archiving is affected. What is more, a memory overflow occurs so that the Yarn service is unavailable.

Possible Causes

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

Procedure

Check the heap memory usage.
1. Go to the cluster details page and choose Alarms.
2. Select the alarm whose Alarm ID is 18009 and view the IP address and role name of the instance in Location.
3. Choose Components > MapReduce > Instance > JobHistoryServer (IP address of the instance for which the alarm is generated) > Customize > JobHistoryServer Heap Memory Usage Statistics. Check the heap memory usage.
4. Check whether the heap memory usage of JobHistoryServer has reached the threshold (80% of the maximum heap memory).
  - If yes, go to 1.e.
  - If no, go to 2.
5. Choose Components > MapReduce > Service Configuration. Set Type to All and choose JobHistoryServer > System. Increase the value of -Xmx in the GC_OPTS parameter as required, click Save Configuration, and select Restart the affected services or instances. Click OK.
6. Check whether the alarm is cleared.
  - If yes, no further action is required.
  - If no, go to 2.
Collect fault information.
1. On MRS Manager, choose System > Export Log.
2. Contact technical support engineers for help. For details, see technical support.

Reference

None