Cannot Delete Knowledge Base

I understand your frustration with being unable to delete your Amazon Bedrock knowledge base. This is a known issue that occurs when the vector store (OpenSearch Serverless) is deleted before the knowledge base itself.

Here are some steps you can try to resolve this issue:

1. Change the data deletion policy:

• Go to the Amazon Bedrock console and navigate to your knowledge base
• Edit the data source that's in a DELETE_UNSUCCESSFUL state
• In Advanced settings, change the Data deletion policy from DELETE to RETAIN
• Save the changes

2. Delete the data source first:

• After changing the data deletion policy to RETAIN, try deleting the data source
• Wait 3-5 minutes after the data source is deleted
• Then attempt to delete the knowledge base

3. Try using a different user account:

• Some users have reported success by switching from the root user to another admin user
• This might help bypass authentication issues that could be preventing deletion

4. If the above steps don't work, you might need to:

• Temporarily recreate the OpenSearch Serverless collection with the same name
• Ensure the knowledge base execution role has sufficient IAM permissions
• Grant the role AdministratorAccess temporarily to rule out permission issues

If you continue to face difficulties, keep trying the deletion process periodically. Some users have reported that their knowledge bases eventually became deletable after repeated attempts, possibly due to background fixes by AWS.
Sources
Bedrock Knowledge base - Delete unsuccessful | AWS re:Post
Resolve the "Failed to delete knowledge base" error in Amazon Bedrock | AWS re:Post
Deleting Knowledgebase - previous advice not working | AWS re:Post
AWS Knowledge Base Deletion | AWS re:Post