Open Search Serverless Collection Dashboard stuck in endless redirection loop

I'm sorry to hear you're experiencing issues accessing your OpenSearch Serverless Collection Dashboard. This redirection loop problem can be frustrating, but there are a few steps we can take to troubleshoot and potentially resolve the issue:

1. First, check if you're seeing any specific errors in your browser's developer tools. This can provide valuable information about what's causing the redirection loop.

2. Try accessing the dashboard from a different browser or network to see if the issue persists. This can help determine if it's a local browser issue or a more widespread problem.

3. Ensure that your IAM user or role has the necessary permissions to access the OpenSearch Serverless collection and its dashboard. Review your IAM policies and the collection's data access policy to confirm you have the correct permissions.

4. If your collection is using VPC access, verify that the security group associated with the VPC endpoint allows inbound traffic from your source (e.g., your EC2 instance or local machine).

5. For collections with VPC access, make sure you're accessing the dashboard through the correct VPC endpoint. You may need to create an EC2 instance in the same VPC as your collection's endpoint and access the dashboard from there.

6. Use the AWS Network Manager's Reachability Analyzer to test connectivity between your source (e.g., EC2 instance) and the collection's VPC endpoint. This can help identify any network-related issues.

7. If you're using SAML authentication, ensure that your SAML configuration is correct and that you're being properly redirected to provide your authentication details.

If these steps don't resolve the issue, it's possible there might be a bug or service-related problem. In that case, it would be best to contact AWS support for further assistance. They can investigate if there are any known issues with the OpenSearch Serverless service and provide more specific guidance based on your account and collection configuration.

Sources
infinite loop on open search serverless dashboard launch | AWS re:Post
Create and access OpenSearch Dashboard for an OpenSearch Serverless collection | AWS re:Post
Troubleshoot access to OpenSearch Serverless dashboard | AWS re:Post