How do I identify which Amazon RDS DB parameters are in custom parameter groups and which are in default parameter groups?

Last updated: 2019-11-05

How can I identify which Amazon Relational Database Service (Amazon RDS) DB parameters are in a custom parameter group and which are in a default group?

Short Description

You can modify parameters for custom DB parameter groups to change or to resolve incompatible-parameter issues. You can compare the differences between the custom parameter group settings. Then, you can determine which values are set by default. For example, you can identify which parameters triggered the incompatible-parameters issue by reviewing the default value. Then, you can compare the custom parameter group to the default parameter group for your database engine.

Resolution

Using the Amazon RDS console

  1. Open the Amazon RDS console, and select the Region that contains the RDS DB instance.
  2. Choose Parameter Groups from the navigation pane.
  3. Choose two parameter groups that you want to compare, and then choose Parameter group actions.
  4. Choose Compare Parameters.

The result is a Parameter Comparison table that lists of all parameters and values. Review the Parameter Comparison table to see the values of parameters for both default and custom parameter groups.

Using the AWS CLI

Use the AWS Command Line Interface (AWS CLI) to compare parameter groups by using the describe-db-parameters and describe-db-cluster-parameters commands.

Run the following command to view the settings for a parameter group, including the source for each:

aws rds describe-db-parameters --db-parameter-group-name INSERT-YOUR-PG-NAME-HERE --region INSERT-REGION-HERE

To list the default value for the engine family, you can use the same command or use the describe-engine-default-parameters command for database-level parameters and the describe-engine-default-cluster-parameters command for cluster-level parameters.

The following example shows the default parameters for the MySQL engine version 5.6 parameter group family:

aws rds describe-engine-default-parameters --db-parameter-group-family mysql5.6

Note: There isn't an AWS CLI command that compares two parameter groups at the same time. This feature is available only in the Amazon RDS console. But you can use the AWS CLI command --output text to list in plaintext instead of the default JSON format. Then, you can compare the plaintext files that list the parameter groups.