RequestTimeTooSkewed: The S3 Error That Brings Teams to a Halt
Clock drift, misaligned regions, and a false sense of reliability.
Problem
It’s late, your team is pushing a routine update, and suddenly every S3 request fails. Instead of success, you’re staring at an XML block with a cryptic message: The app pushes an object to S3, but instead of a success response, you get:
<Error>
<Code>RequestTimeTooSkewed</Code>
<Message>The difference between the request time and the current time is too large.</Message>
</Error>
At first glance, it looks like S3 is rejecting your request for no reason. But behind this cryptic error lies a simple culprit: your system’s clock is out of sync with AWS. A few minutes of drift is enough to grind uploads, downloads, and even signed URL access to a halt.
Clarifying the Issue
S3 requires requests to carry a valid timestamp that’s close to the actual AWS system time. If your client’s clock drifts beyond 5 minutes, S3 rejects the request with RequestTimeTooSkewed. This often happens when:
- NTP (Network Time Protocol) isn’t configured or is failing.
- Servers run in different regions with mismatched time sync sources.
- Containerized workloads inherit host clocks that aren’t accurate.
It’s not random, and it’s not AWS failing — it’s clock drift, plain and simple.
Why It Matters
A skewed clock seems small, but the consequences aren’t:
- Service disruption: All S3 operations relying on signatures fail.
- Broken integrations: Pre-signed URLs stop working for customers.
- Support escalations: Teams waste hours chasing a “network” issue that’s really time sync.
- Security implications: Time drift undermines the integrity of cryptographic signatures and audits.
This is a reliability problem disguised as a minor configuration issue. AWS enforces strict time alignment because every S3 request is cryptographically signed (Signature Version 4). The timestamp ensures signatures can’t be reused in replay attacks, so even small clock drift invalidates the request.
Key Terms
- RequestTimeTooSkewed: Error returned when request timestamps differ too much from AWS server time.
- NTP (Network Time Protocol): Protocol used to synchronize clocks across systems.
- Pre-signed URL: A time-bound link granting temporary access to an S3 object.
- Clock Drift: Gradual deviation of a system’s clock from the actual time.
Steps at a Glance
- Verify the error in logs.
- Check and sync system clocks.
- Configure NTP or chrony for ongoing accuracy.
- Align container and host clocks.
- Monitor clock drift continuously.
Detailed Steps
1. Verify the Error in Logs
Look for RequestTimeTooSkewed entries in application logs or CloudTrail events:
grep "RequestTimeTooSkewed" /var/log/app.log
2. Check and Sync System Clocks
Compare your system time to a trusted source:
date -u
ntpdate -q time.google.com
3. Configure NTP or Chrony for Ongoing Accuracy
On Linux, install and enable chrony:
sudo yum install -y chrony
sudo systemctl enable chronyd
sudo systemctl start chronyd
chronyc tracking
4. Align Container and Host Clocks
Ensure Docker or Kubernetes containers use the host’s synchronized clock. Misconfigured virtualization layers often amplify drift.
5. Monitor Clock Drift Continuously
Set up alerts if drift exceeds a threshold. Example with CloudWatch Agent:
{
"metrics": {
"append_dimensions": { "InstanceId": "${aws:InstanceId}" },
"metrics_collected": {
"ntp": { "measurement": "offset", "unit": "Milliseconds" }
}
}
}
Conclusion
The RequestTimeTooSkewed error isn’t about S3 being down — it’s your infrastructure being out of sync. By verifying logs, syncing clocks, configuring NTP/chrony, aligning container time, and monitoring drift, you eliminate a hidden single point of failure.
In the cloud, time is more than a number — it’s a dependency. Keep it aligned, and your systems keep moving.
Aaron Rose is a software engineer and technology writer at tech-reader.blog and the author of Think Like a Genius.
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