Fixing an Amazon Bedrock RequestExpired 400 Error

Fixing an Amazon Bedrock RequestExpired 400 Error

Question

How Do I Fix an Amazon Bedrock RequestExpired 400 Error?

Clarifying the Issue

The RequestExpired (400) error occurs when an API request to Amazon Bedrock is sent too long after the timestamp in the request, or when the request's expiration time (such as in a pre-signed URL) has passed. This error can also occur if the request’s timestamp is more than 15 minutes in the future, indicating a potential issue with your system clock or request signing process.

This error is typically encountered when using AWS SDKs, CLI commands, or API requests that require signature authentication. If the request takes too long to reach AWS servers or has an incorrect timestamp, AWS rejects it with a 400 Bad Request response.

Why It Matters

Timestamp-based request validation is a key security measure in AWS. It prevents replay attacks, where an attacker could intercept a request and resend it later to perform unauthorized actions. However, if your system clock is incorrect or if your request is delayed for some reason, you may encounter this error—even if your credentials and API calls are otherwise correct.

This can be particularly problematic for automated workflows, serverless applications, or pre-signed URLs that depend on precise timing to function properly. If unresolved, it can cause API failures and disrupt critical processes in your application.

Key Terms

• RequestExpired (400 Error): Indicates that an AWS API request was received too late or had an invalid timestamp.
• Pre-Signed URLs: Temporary URLs that grant access to AWS resources with an expiration time.
• AWS Signature Version 4 (SigV4): The method AWS uses to authenticate API requests, requiring a correct timestamp.
• System Clock Skew: A mismatch between your local system time and AWS's time, which can cause request failures.

Steps at a Glance

1. Check Your System Clock – Ensure your local system time is synchronized with AWS servers.
2. Verify AWS Signature Generation – If using custom API requests, ensure your signature includes a valid timestamp.
3. Check for Delayed Requests – Investigate whether network delays or retries are causing expired requests.
4. Adjust Pre-Signed URL Expiry – If using pre-signed URLs, increase the expiration time if needed.
5. Use AWS SDKs or CLI Correctly – Ensure you are using up-to-date AWS SDKs or CLI tools to avoid signature mismatches.

Detailed Steps

1. Check Your System Clock

One of the most common causes of this error is clock skew, where your system's time is out of sync with AWS servers. AWS requires requests to be timestamped within a 15-minute window.

On Linux/macOS, run:

Bash

date

On Windows, open Command Prompt and run:

Bash

w32tm /query /status

If your system time is incorrect, sync it with a reliable time source:

On Linux/macOS:

Bash

sudo ntpdate -u pool.ntp.org

On Windows, enable automatic time synchronization in the system settings.

2. Verify AWS Signature Generation

If you are manually signing requests, make sure the timestamp included in the request is correct and formatted according to AWS Signature Version 4 requirements.

The timestamp should be in ISO 8601 format, e.g., 20240314T120000Z.

If using an AWS SDK, ensure it automatically applies the correct signature and timestamp.

3. Check for Delayed Requests

If your API request is delayed due to network latency, long processing times, or retry mechanisms, it may arrive at AWS after the 15-minute window.

Review logs to see when the request was generated vs. when it was received by AWS.

If using an asynchronous system, ensure the request is being sent immediately after being generated.

4. Adjust Pre-Signed URL Expiry

If using pre-signed URLs, they may be expiring too quickly. The expiration time is set when the URL is generated.

If you need a longer validity period, increase the expiration time when creating the URL:

Python

import boto3

s3 = boto3.client('s3')
url = s3.generate_presigned_url(
    'get_object',
    Params={'Bucket': 'my-bucket', 'Key': 'myfile.txt'},
    ExpiresIn=3600  # Extend to 1 hour (3600 seconds)
)
print(url)

5. Use AWS SDKs or CLI Correctly 

Ensure you are using the latest AWS SDKs or AWS CLI version:

Bash

aws --version

Bash

pip install --upgrade boto3

If you are making requests via AWS CLI and encountering this error, try:

Bash

aws s3 ls --debug

This will output debug logs showing request timestamps and any potential issues with request expiration.

Conclusion

The RequestExpired (400) error in Amazon Bedrock is usually caused by clock skew, expired pre-signed URLs, or delayed API requests. The first step is to ensure your system clock is accurate, as even small discrepancies can cause AWS to reject your request. If the error persists, check your signature process, API request timing, and expiration settings for pre-signed URLs.

By following these troubleshooting steps, you can quickly resolve this issue and ensure your API calls function smoothly. 🚀

Need AWS Expertise?

If you're looking for guidance on Amazon Bedrock or any cloud challenges, feel free to reach out! We'd love to help you tackle AWS projects. 🚀

Email us at: info@pacificw.com

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