How can I resolve 400 error messages when modifying my Amazon Aurora DB instance?

Last updated: 2020-12-21

I have an Amazon Aurora DB instance that I want to modify. I receive a Status Code: 400 error message when I make a modification request on my DB instance. How can I troubleshoot and resolve 400 errors on my DB instance?

Short description

When you initiate an API request, AWS performs initial syntax checks to make sure that the API request is complete and has all the mandatory parameters. There are a number of reasons that a 400 error can occur when you send an API request to modify your Amazon Aurora DB instance, including:

  • Your request was denied because of API request throttling
  • You used an invalid parameter combination
  • You used an invalid or out-of-range value for the input parameter
  • The API is missing either a required parameter or an action
  • Browser issues caused the API to fail
  • You are using an outdated AWS Command Line Interface (AWS CLI) version
  • A Large Scale Event (LSE) affected the service and caused the API to fail

Follow the troubleshooting steps in this article to resolve each of these issues.


Note: If you receive errors when running AWS CLI commands, make sure that you’re using the most recent version of the AWS CLI.

Throttling Exception

Your request was denied because of API request throttling. These API call limits are at account level, and are not specific to any service.

Note: You can't increase or modify limits for a particular call. AWS makes sure that API calls (whether they come from an application, call to a command line interface, or the AWS Management Console) don't exceed the maximum allowed API request rate.

You can avoid this error by using these methods:

  1. Use exponential backoff and jitter.
  2. Distribute API calls evenly over time (instead of having all the API calls occur at the same time).

Invalid parameter combination

If you use a combination of parameters when you modify your DB instance, you receive a 400 error. To resolve this issue, use only valid parameters/arguments in the API call.

Invalid input parameter

If you use a parameter that AWS does not allow, you receive a 400 error. Run the describe-db-parameters command with the AWS CLI to review which parameters are allowed, and then remove the invalid input parameter before modifying your DB instance.

Missing parameter

AWS denies your request if you use an invalid or out-of-range value for the input parameter. Check that you have included all mandatory parameters/fields in the API request before modifying your DB instance.

Browser issue

Intermittent browser issues can cause your API call to fail. To resolve browser issues, try clearing your cache and then issue the API again. If this doesn't work, try again in a different browser.

Outdated CLI version

If you are using the AWS CLI to issue the API request, upgrade to the most recent version. Older versions of the AWS CLI may not support the use of certain parameters, so it is important to regularly check that your version is up to date. For more information, see Install and update the AWS CLI version 1 using pip.

Large Scale Event (LSE)

A 400 error can occur if there is an ongoing issue or LSE that is affecting Amazon Relational Database Service (Amazon RDS) or one of its dependent services. To check if there is any on-going issue, review the AWS Personal Health Dashboard and the Service Health Dashboard. Continue to monitor the dashboards for an update on the root cause and resolution.