Timeout doesn't seem to be respected

[TommyN]

Describe the bug

We have a net6.0 Lambda function (512MB Memory) with a timeout set to 2 seconds.
For some reason the timeout value doesn't seem to be respected:

---

@message
Task timed out after 2.53 seconds
Task timed out after 4.00 seconds
Task timed out after 2.54 seconds
Task timed out after 4.00 seconds
Task timed out after 2.54 seconds
Task timed out after 4.00 seconds
Task timed out after 2.52 seconds
Task timed out after 4.00 seconds
Task timed out after 2.54 seconds
Task timed out after 4.00 seconds
Task timed out after 2.53 seconds
Task timed out after 4.00 seconds
Task timed out after 2.53 seconds
Task timed out after 4.00 seconds
Task timed out after 2.58 seconds
Task timed out after 4.00 seconds

---

Expected Behavior

I expected the function to time out after 2 seconds

Current Behavior

Function times out after 4 seconds. Billing is limited to 2 seconds.

Duration: 4003.89 ms Billed Duration: 2000 ms Memory Size: 512 MB Max Memory Used: 512 MB

Reproduction Steps

N/A

Possible Solution

No response

Additional Information/Context

No response

AWS .NET SDK and/or Package version used

Amazon.Lambda.Core Version="1.1.0"

Targeted .NET Platform

NET 6

Operating System and version

.NET 6 (C#/PowerShell)

[ashishdhingra]

Hi @TommyN,

Good afternoon.

Thanks for reporting the issue. Please share the sample code to help reproduce the issue ay our end.

Regards,
Ashish

[TommyN]

This happened 16 times over the last 4 days.
The Lambda function was invoked 25M times, so I don't have a sample that will easily provoke the issue.

[ryanwilliams83]

You may wish to consder var cts = new CancellationTokenSource(TimeSpan.FromSeconds(2)); and then passing cts.Token into your async methods to get a more precise timeout.

[normj]

I'm gonna close this ticket because it is pretty old and probably not actionable anymore. Lambda has changed quite a bit since this issue first reported but I wonder if the original issue was the 4 second timeouts where the cold starts and I don't think the init part counts towards the timeout.