Nova Premier fails in dotnet AWS Lambda with Signature expired exception

Based on the error message, you're encountering a signature expiration issue specifically with Nova Premier in your AWS Lambda function. This error occurs when there's a time discrepancy between when the request was signed and when it was processed.

The error shows that your request was signed at 16:26:49 UTC but by the time it was processed, the server time was 16:31:57 UTC - more than 5 minutes later. AWS API requests typically expire after 5 minutes for security reasons.

This issue appears to be specific to Nova Premier and not other models like Nova Pro or Llama 4. The most likely explanation is that Nova Premier, being Amazon's most capable model in the Nova family, requires significantly more computational resources and processing time than the other models you've tried.

Nova Premier is designed for complex tasks and has a much larger context window (up to one million tokens), which could be causing longer processing times when invoked through Lambda. The request is timing out because the model initialization or processing is taking longer than the signature validity period.

To resolve this issue, you could try:

1. Increasing your Lambda function timeout to accommodate the longer processing time
2. Implementing request retries with exponential backoff
3. Using a Lambda layer or container image to pre-warm the model
4. Consider using Nova Pro instead if it meets your needs, as it's more optimized for lower latency while still offering good capabilities

If you absolutely need Nova Premier's capabilities, you might need to architect your solution differently to account for the longer processing times.
Sources
Amazon Nova Premier: Our most capable model for complex tasks and teacher for model distillation | AWS News Blog
Amazon Nova Premier, our most capable model for complex tasks and teacher for model distillation - AWS