Help Center/ MapReduce Service/ User Guide (Ankara Region)/ Alarm Reference/ ALM-50212 Accumulated Old-Generation GC Duration of the FE Process Exceeds the Threshold

Updated on 2024-11-29 GMT+08:00

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ALM-50212 Accumulated Old-Generation GC Duration of the FE Process Exceeds the Threshold

Alarm Description

The system checks the accumulated old-generation GC duration of the FE process every 30 seconds. This alarm is generated when the accumulated GC duration exceeds the threshold (3000 ms by default).

This alarm is cleared when the system detects that the accumulated old-generation GC duration of the FE process is less than the threshold.

Alarm Attributes

Alarm ID	Alarm Severity	Alarm Type	Service Type	Auto Cleared
50212	Major	Quality of service	Doris	Yes

Alarm Parameters

Type	Parameter	Description
Location Information	Source	Specifies the cluster or system for which the alarm is generated.
	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.
Additional Information	Detail	Specifies the alarm triggering condition.

Impact on the System

A long GC duration of the FE process may interrupt the services.

Possible Causes

The heap memory of the FE process is overused or inappropriately allocated, causing frequent occurrence of the GC process.

Handling Procedure

Check the GC duration.

On FusionInsight Manager, choose O&M > Alarm > Alarms. In the alarm list, view the role name and obtain the IP address of the instance in Location of the alarm whose ID is 50212.
Choose Cluster > Services > Doris > Instances, click the FE instance for which the alarm is generated, and click the Chart tab of the instance.
Select JVM from Chart Category on the left, and check whether Accumulated GC duration of the old generation of the FE process is greater than 3 seconds.
- If yes, go to 3.
- If no, go to 5.
Choose Cluster > Services > Doris > Configurations > All Configurations > FE(Role) > JVM, and increase the value of -Xmx in FE_GC_OPTS. The default value is 8G.
- If this alarm is occasionally generated, increase the value by 0.5 times. If this alarm is frequently generated, double the value.
- In the case of large service volume and high service concurrency, you are advised to add instances.
Check whether the alarm is cleared.
- If yes, no further action is required.
- If no, go to 5.

Collect fault information.

On FusionInsight Manager, choose O&M. In the navigation pane on the left, choose Log > Download.
Expand the Service drop-down list, and select Doris for the target cluster.
Click the edit icon in the upper right corner, and set Start Date and End Date for log collection to 30 minutes ahead of and after the alarm generation time, respectively. Then, click Download.
Contact O&M engineers and provide the collected logs.