ALM-46007 MOTService Database Enters the Read-Only Mode

Alarm Description

The system checks the disk space usage of the data directory on the active MOTServer node every 30 seconds. This alarm is generated when the disk space usage of the data directory exceeds 70%.

This alarm is cleared when the disk space usage of the data directory falls below 70%.

Alarm Attributes

Alarm ID	Alarm Severity	Alarm Type	Service Type	Auto Cleared
46007	Critical	Quality of service	MOTService	Yes

Alarm Parameters

Type	Parameter	Description
Location Information	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.
Additional Information	Trigger Condition	Specifies the threshold for triggering the alarm.

Impact on the System

The MOTService database in read-only mode cannot provide the data import function for upper-layer services.

Possible Causes

The disk configuration cannot meet service requirements. The disk usage reaches the upper limit.

Handling Procedure

Check whether the disk space usage reaches the upper limit.

On FusionInsight Manager, choose Cluster > Services > MOTService.
On the Dashboard page, view the MOT Disk Space Usage of the Data Directory chart to check whether the disk space usage of the data directory exceeds 70%. If the chart is not displayed, click on the right and click Customize to select the chart.

If yes, go to 3.

If no, go to 9.
Click the Instance tab and obtain the service IP address of the active MOTService instance.
Run the following commands to check whether the database enters the read-only mode:

source $MOTSERVER_HOME/.motservice_profile

gsql -d postgres -p 20105

Enter the password of user omm for the MOTService database.

show default_transaction_read_only;
- Contact the cluster administrator to obtain the omm password of the MOTService database.
- You can run the \q command to exit the database.
Check whether the value of default_transaction_read_only is on.
```
openGauss=# show default_transaction_read_only;
 default_transaction_read_only
-------------------------------
 on
(1 row)
```
- If yes, go to 5.
- If no, go to 9.
Log in to the active MOTServer node as user omm. Run the following commands to check whether files with more than 500 MB are incorrectly written into the disk space of the data directory:

source $MOTSERVER_HOME/.motservice_profile

find "$MOTSERVICE_DATA_DIR"/../ -type f -size +500M
- If yes, go to 6.
- If no, go to 9.
Delete the incorrectly written files based on site requirements.
Run the following command to disable the read-only mode of the database:

gs_guc reload -Z datanode -N all -I all -c "default_transaction_read_only=off"
Check whether the alarm is cleared.
- If yes, no further action is required.
- If no, go to 9.

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 choose Containers > CenterServer.
Expand the Hosts drop-down list. In the Select Host dialog box that is displayed, select the hosts to which the role belongs.
Click the edit icon 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 O&M personnel/Technical support and provide the collected logs.