Unable to connect Amazon RDS for PostgreSQL to Appflow


I get the following error when adding an Amazon RDS for PostgreSQL as a connection in Appflow, following these instructions: https://docs.aws.amazon.com/appflow/latest/userguide/connectors-amazon-rds-postgres-sql.html

"Error while communicating to the connector: Failed to validate Connection while attempting "ValidateCredentials with CustomConnector" with connector failure The request failed because the service Source Amazon RDS returned the following error: Details: Unable to connect to the database., ErrorCode: InvalidArgument. (Service: null; Status Code: 400; Error Code: Client; Request ID: null; Proxy: null)"

I can connect to the RDS instance pgAdmin, but for some reason I get this error when connecting on Appflow. The security group has All traffic set to anywhere for both inbound and outbound rules.

Are there additional requirements to connect to Appflow?

asked a year ago613 views
3 Answers


Can you confirm that you are not configuring Amazon RDS for PostgreSQL as data source? According to AWS documentation, you can use Amazon AppFlow to transfer data to Amazon RDS for PostgreSQL, but not to read it.

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answered a year ago

Yes, it is the destination. Google Analytics 4 is the source. I am working with this documentation: Google Analytics 4 connector for Amazon AppFlow.

answered a year ago

I am stuck on this same error as well. Haven't come across any solutions, only reports of this InvalidArgument error. Would be nice to know which argument is invalid.

The AWS docs are lacking on some details here:

  • does the database have to be publicly accessible (assigned a public IP)? It hasn't worked for me either way.
  • is there some security group configuration required to allow AppFlow to write to RDS?
  • what is the database name? is it 'postgres'? just the username? the "DB name" property in the database's configuration tab, which is set by some buried setting when creating the database?
answered 2 months ago

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