Python Lambda Function - Timeout error

Question

Hello team,
I Have a lambda function (in Python code) that it's execution works fine 4/5 times, but suddenly it return this error message: "...Task timed out after  seconds" for some time (and execution) and after that it returns to work fine. I already increased the lambda's **Timeout ** and the **Memory** (although when the execution works the Report says that it took ~500ms and 29mb of memory) but it didn't solve the problem. 
I tried to comment some parts of the code to understand eventually bug, but it looks like a "random" error.
The log shows something like this (my "print" statements are not logged):
`INIT_START Runtime Version: python:3.10.v5	Runtime Version ARN: .....
START RequestId: ... Version: $LATEST
2023-07-05T09:44:11.982Z ..... Task timed out after 5.01 seconds
END RequestId: ...
REPORT RequestId: ....	Duration: 5007.99 ms	Billed Duration: 5000 ms	Memory Size: 1024 MB	Max Memory Used: 29 MB	
INIT_START Runtime Version: python:3.10.v5	Runtime Version ARN: .....`
By the way the function mount an EFS, I configured the SecurityGroup for the lambda and that for the VPC, where the EFS is located, but I think there isn't a configuration problem, because when the error doesn't come in, the function is integrated perfectly with the EFS, otherwise I think it shouldn't have worked at all.

Please let me know if I have missed anything or something I can try to fix the issue or investigate the cause better.

Thank you for your time, E.

efalcone · Accepted Answer

Hi team, finally I found; there was a problem with s3 and the code config; I added this config on my code, when S3 boto3 client is created: config=botocore.config.Config(s3={'addressing_style': 'path'}).

Thanks to all.

Steve Kinsman · Answer

I don't know what sort of configuration and exception-handling you have in your code, but is it possible you're getting API request-throttling?  Boto3 handles some of this for you, retrying API calls rejected due to throttling and retrying with exponential backoff up to a retry limit.  See https://boto3.amazonaws.com/v1/documentation/api/latest/guide/retries.html.

In summary there are 3 modes - Default/Legacy, Standard and Adaptive (experimental).
You can configure the mode and number of retries (5 by default). Retrying is exponential backoff base 2.

You can monitor retrying either in Boto3's logging (if enabled) or in the response to API calls. It's not clear from the doco but along with the documented structure returned by each call there's also ResponseMetadata with RetryAttempts in it.

Antonio_Lagrotteria · Answer

Seems as your function timed out after 5 seconds, have you increased that to lets say 30sec?

Is your lambda in the same VPC as the EFS file system?

Python Lambda Function - Timeout error

Relevant content