Control: 6.2.15 Ensure that the 'log_temp_files' database flag for Cloud SQL PostgreSQL instance is set to '0'

Description

PostgreSQL can create a temporary file for actions such as sorting, hashing and temporary query results when these operations exceed work_mem. The log_temp_files flag controls logging names and the file size when it is deleted. Configuring log_temp_files to 0 causes all temporary file information to be logged, while positive values log only files whose size is greater than or equal to the specified number of kilobytes. A value of -1 disables temporary file information logging.

Default value for log_temp_files flag is -1.

If all temporary files are not logged, it may be more difficult to identify potential performance issues that may be due to either poor application coding or deliberate resource starvation attempts.

Remediation

From Console:

1. Login to GCP console and navigate to Cloud SQL Instances.
2. Select the PostgreSQL instance for which the database flag needs to be enabled.
3. Click EDIT.
4. Scroll down to the Flags section.
5. Click ADD FLAG, choose the log_temp_files from the drop-down menu, and set to 0.
6. Click SAVE.
7. Confirm the changes under Flags on the Overview page.

From Command Line:

1. List all Cloud SQL database instances using the following command

gcloud sql instances list

2. Configure the log_temp_files database flag for every Cloud SQL PostgreSQL database instance using the below command

gcloud sql instances patch INSTANCE_NAME --database-flags log_temp_files=`0`

Note

• This command will overwrite all previously set database flags. To keep those and add new ones, include the values for all flags to be set on the instance. Any flag not specifically included is set to its default value. For flags that do not take a value, specify the flag name followed by an equals sign ("=").
• Configuring the above flag does not require restarting the Cloud PostgreSQL instance.