Google CloudOverview
It is recommended to check the user connections for a Cloud SQL SQL Server instance to ensure that it is not artificially limiting connections.
Rationale
The user connections option specifies the maximum number of simultaneous user connections that are allowed on an instance of SQL Server. The actual number of user connections allowed also depends on the version of SQL Server that you are using, as well as the limits of your application or applications and hardware. SQL Server allows a maximum of 32,767 user connections. Because user connections is by default a selfconfiguring value, SQL Server adjusts the maximum number of user connections automatically as needed, up to the maximum value allowable. For example, if only 10 users are logged in, 10 user connection objects are allocated. In most cases, you do not have to change the value for this option. The default is 0, which means that the maximum (32,767) user connections are allowed. However if there is a number defined here that limits connections, SQL Server will not allow anymore above this limit. If the connections are at the limit, any new requests will be dropped, potentially causing lost data or outages for those using the database.
Impact
Setting custom flags via command line on certain instances will cause all omitted flags to be reset to defaults. This may cause you to lose custom flags and could result in unforeseen complications or instance restarts. Because of this, it is recommended you apply these flags changes during a period of low usage.
Remediation guidance
From Google Cloud Console
- Go to the
Cloud SQL Instancespage in the Google Cloud Console by visiting https://console.cloud.google.com/sql/instances - Select the SQL Server instance where the database flag needs to be enabled
- Click
EDIT - Scroll down to the
Flagssection - To set a flag that has not been set on the instance before, click
ADD A DATABASE FLAG, choose the flaguser connectionsfrom the drop-down menu, and set its value to the value recommended by your organization - Click
SAVE - Confirm the changes under
Flagson theOverviewpage
Using Google Cloud CLI
Configure the user connections database flag for every Cloud SQL SQL Server database instance using the below command.
gcloud sql instances patch <instanceName> --database-flags "user connections=[0-32,767]"
Default Value
By default, user connections is set to 0, which does not limit the number of connections, giving the server free reign to facilitate a maxmum of 32,767 connections.
References
- https://cloud.google.com/sql/docs/sqlserver/flags
- https://learn.microsoft.com/en-us/sql/database-engine/configure-windows/configure-the-user-connections-server-configuration-option?view=sql-server-ver15
- https://www.stigviewer.com/stig/ms_sql_server_2016_instance/2018-03-09/finding/V-79119
Additional information
WARNING: This patch modifies database flag values, which may require the instance to be restarted. Check the list of supported flags https://cloud.google.com/sql/docs/sqlserver/flags - to see if your instance will be restarted when this patch is submitted.
Note: Configuring the above flag restarts the Cloud SQL instance.
Service-wide remediation
Recommended when many resources are affected: fix the platform baseline first so new resources inherit the secure setting, then remediate the existing flagged resources in batches.
Google Cloud
Use organization or folder policies where available, shared project templates, logs and alerting baselines, and IaC modules so new resources inherit the secure setting.
Operational rollout
- Fix the baseline first at the account, subscription, project, cluster, or tenant scope that owns this control.
- Remediate the currently affected resources in batches, starting with internet-exposed and production assets.
- Re-scan and track approved exceptions with an owner and expiry date.
Query logic
These are the stored checks tied to this control.
Ensure 'user connections' database flag for Cloud Sql Sql Server instance is set to a non-limiting value
Connectors
Covered asset types
Expected check: eq []
{
cloudSqlInstances(
where: {
cloudProvider: "gcp"
engine: "sqlserver"
dbFlags_SOME: { name: "user connections" }
}
) {
...AssetFragment
}
}
