Common errors encountered while using Serverless Functions

Reviewed on 03 January 2024 • Published on 23 August 2023

Handler not found

Function Handler does not exist, check that you provided the right HANDLER parameter …

Or

Provided Handler does not exist, or does not export methods properly

The systems cannot find the function which will handle the request. It can be related to an error in your code before your handle function.

Make sure to provide the right handler path.
If you used a zip file, make sure the dependencies are present in your zip package.
If you used the Serverless framework, ensure the .serverless directory created with serverless package contains your zip file.
Make sure that the dependencies folders (node_modules or package in Python) are in package/include.
Serverless Functions rely on Alpine Linux, therefore, some C-based libraries (pandas, tensorflow, numpy) will not work. Refer to the official documentation to safely add these libraries to your package.

Too many retries, sub-runtime server did not come up in 10ms seconds

This error is returned by the runtime when it cannot process the request. It has several different origins.

Make sure that you only imported the required dependencies and not the complete libraries.
Avoid performing too many initialization operations.
Update your function’s resources by provisioning more memory and more vCPU.

Timeout happens when your function can’t return a results in the defined amount of time.

This issue can happen for the following reasons:

Make sure that you did not exceed the maximum number of allowed namespaces with the Scaleway console or with the API.