This page lists known issues with Cloud SQL for SQL Server, along with ways you can avoid or recover from these issues.
Instance connection issues
Expired SSL/TLS certificates
If your instance is configured to use SSL, go to the Cloud SQL Instances page in the Cloud Console and open the instance. Open its Connections page and make sure that your server certificate is valid. If it has expired, you must add a new certificate and rotate to it. Learn more.
Cloud SQL Auth proxy version
If you are connecting using the Cloud SQL Auth proxy, make sure you are using the most recent version. For more information, see Keeping the Cloud SQL Auth proxy up to date.
Not authorized to connect
If you try to connect to an instance that does not exist in that project, the error message only says that you are not authorized to access that instance.
A large export operation can adversely affect instance availability
Before starting a large export, ensure that at least 25 percent of the database size is free (on the instance). Doing so helps prevent issues with aggressive autogrowth, which can affect the availability of the instance.
If the database version of your SQL Server instance is SQL Server 2017 Express:
If you specify a flag when you create a new instance, creation of the instance fails.
You cannot set database flags on an existing instance.
Long-running Cloud SQL instance operations cannot be cancelled or stopped
When you start a long-running Cloud SQL instance operation, such as an import or export operation, you cannot stop the operation before it completes. In addition, only one operation can run against an instance at at time.
For this reason, make sure you do not need to do other work on an instance when you start a long-running operation.
Instance names cannot be reused immediately after instance deletion
After you delete an instance, you cannot immediately reuse the instance name, because Cloud SQL reserves that name for a few days. If you need to create and delete instances with the same name, consider using a timestamp as part of the name to avoid name conflicts.
Issues with importing and exporting data
Do not create a BAK file (for import) from a read-only database or from a database that is in single-user mode. If you create a BAK file from a read-only database or from a database that is in single-user mode, and import that file, an error may occur.
Transaction logs and disk growth
Logs are purged once daily, not continuously. When the number of days of log retention is configured to be the same as the number of backups, a day of logging might be lost, depending on when the backup occurs. For example, setting log retention to seven days and backup retention to seven backups means that between six and seven days of logs will be retained.
We recommend setting the number of backups to at least one more than the days of log retention to guarantee a minimum of specified days of log retention.