How do I troubleshoot an Amazon RDS DB instance that's stuck in the incompatible-parameters state?

Resolution

When an Amazon RDS DB instance shows the incompatible-parameters state, at least one parameter value is incompatible with the engine version or DB instance class.

This issue can occur for the following reasons:

• Your DB instance scales to an instance type that has less memory available. At least one of the memory settings in the associated parameter group exceeds the memory size available for the new DB instance.
• A database engine upgrades to a different version and is no longer compatible with one or more parameter settings of the custom parameter group.

The incompatible-parameters state is a terminal state. When your DB instance is in a terminal state, you can only reboot or delete the instance. To associate a different parameter group, scale the instance type, change the engine version, or modify the instance configuration, you must fix the incompatible parameters.

Note: Amazon RDS doesn't identify the incompatible parameter in the parameter group.

To resolve this issue, take one of the following actions:

• Reset all the parameters in the parameter group to the default value.
• Identify the incompatible parameters, and then modify the values of those parameters. To apply the new settings, reboot the instance.

Note: When you change parameter values, the modifications affect all associated DB instances. Before you reset the values, copy the incompatible parameter group as a backup.

To identify the incompatible parameters, compare the differences between the custom parameter group values and the default parameter group values. When you compare the values, Amazon RDS generates a Parameter Comparison table. The table doesn't show engine-default parameter values because those values are specific to the engine version and configuration settings of your Amazon RDS.

Note: To view changes to your custom parameter group, use AWS CloudTrail. Filter the Event name for ModifyDBParameterGroup or ModifyDBClusterParameterGroup within the last 90 days.

For information about Oracle parameters that are incompatible with Amazon RDS, see Turning on HugePages for an RDS for Oracle instance.

Related information

How do I resolve issues with an Amazon RDS DB in an incompatible network state?