Amazon Bedrock might return no output or an empty response due to several factors. Here are the most common causes:
1. Input Format or Validation Issues Bedrock requires specific input formats depending on the foundation model used. For example:
- Missing required parameters (e.g.,
promptfor text generation ormessagesfor conversational models). - Invalid data types (e.g., passing a string instead of a list for multi-turn conversations).
- Exceeding model-specific limits, such as input token counts. For instance, Anthropic’s Claude models reject requests exceeding 100,000 tokens. If the input fails validation, Bedrock may return an empty response instead of processing the request. Always validate inputs against the model’s API documentation before sending requests.
2. Content Filtering or Safety Mechanisms Many Bedrock models include built-in content moderation:
- Inputs flagged as harmful (e.g., hate speech, violent content) may trigger filters, resulting in no output.
- Outputs deemed unsafe might be suppressed entirely. For example, Amazon Titan text models return empty responses if generated content violates their safety policies.
Check Bedrock’s response headers (e.g.,
x-amzn-bedrock-output-safety-checks) for moderation flags. Adjust prompts or use model-specific configuration parameters (like Claude’ssystemprompt for content guidelines) to avoid triggering filters.
3. Service Quotas or Throttling AWS enforces account-level and region-specific quotas:
- Exceeding the maximum Transactions Per Second (TPS) for a model (e.g., 10 TPS for Jurassic-2) causes throttling, which may manifest as empty responses.
- Reaching monthly inference token limits (if applicable) could block further requests.
Monitor usage via CloudWatch metrics (
Invocations,ThrottledInvocations) and implement retries with exponential backoff in your code. Use the AWS Service Quotas console to check or request quota increases.
Additional Considerations
- Model Availability: Ensure the model you’re invoking is enabled in your AWS region.
- Permissions: Verify the IAM role has
bedrock:InvokeModelpermissions. - Network Issues: Timeouts or connectivity problems might interrupt responses.
- Model-Specific Behavior: Some models return empty outputs for ambiguous queries rather than hallucinating answers.
Always enable AWS CloudTrail logging and check Bedrock’s error codes (e.g., ThrottlingException, ValidationException) to diagnose issues systematically.