Replica DB Max Connections Display Error - Max_connections Value Mismatch

[davidhsu]

Environment Details:

We are experiencing an issue in our Google Cloud environment related to max_connections settings displayed for replica databases. Specifically, the primary database and its replica have different max_connections values configured, but the monitoring trend graph is displaying both of them with the same maximum connections value. This discrepancy does not align with the actual database settings.

Issue Description:

• Primary Database: Configured with max_connections set to 10,000.

• Replica Database: Configured with max_connections set to 6,000.

• Trend Graph Issue: In Cloud Monitoring, the trend graph displays both the primary and replica databases as having 10,000 maximum connections, even though the replica is configured with a lower value.

This issue seems to be impacting the accuracy of monitoring data for all master-replica database configurations in our environment.

Troubleshooting Steps Performed:

• Verified that each database's max_connections settings are correct (i.e., 10,000 for the primary and 6,000 for the replica).

• Checked the data source in Cloud Monitoring and confirmed that the values displayed do not match the actual configuration.

Additional Information:

• This issue appears to be a UI display error within Cloud Monitoring.

• It can be replicated by following similar steps in a comparable master-replica setup.

Assistance Request:

We kindly request any insights or recommendations on how to ensure that Cloud Monitoring accurately displays the max_connections values for replica databases. Is this a known issue with the display in monitoring, or is there a specific configuration step we might be missing?

Any help or guidance would be greatly appreciated.

Thank you!

Best Regards 
David

[ChieKo]

Hi @davidhsu,

Welcome to Google Cloud Community!

The problem you're describing is a display error in Google Cloud Monitoring, not a misconfiguration of your databases. Since you've verified the max_connections settings are correct on both the primary and replica instances.

Here's a breakdown of how to proceed, based on general Google Cloud best practices and troubleshooting approaches:

1. Report the bug to Google Cloud Support:

Since you've replicated the issue and confirmed the database settings are correct. Google Cloud Support can investigate this further, potentially identifying a known issue or a fix in the works or you can follow up on the ticket. Providing them with steps performed, screenshots, project ID (anonymized if necessary for private reasons), database type and version numbers will greatly aid their investigation.

2. Alternative monitoring approaches:

While waiting for a resolution from Google Cloud Support, consider these temporary workarounds to get accurate monitoring data:

• Cloud Logging: Check Cloud Logging for potential errors related to Cloud Monitoring's interaction with your database instances. This could offer clues about underlying issues.
• Custom Metrics in Cloud Monitoring: As a more complex workaround, you could potentially create custom metrics in Cloud Monitoring that directly query your database instances for max_connections. This requires more development effort but guarantees accurate data.

I hope the above information is helpful.