Add configurable Lambda execution timeout parameter in Instance Scheduler template

[clekyim]

Is your feature request related to a problem? Please describe.

Yes. We use the Instance Scheduler across our organization, which currently manages 514 AWS accounts (and growing). The Lambda function frequently reaches its hardcoded 5-minute timeout limit, causing incomplete executions — some accounts’ resources are not started or stopped as scheduled. Our tests show that the scheduler now requires up to 8 minutes to complete. However, the timeout value cannot be modified via the template and must be changed manually for each Lambda function, which is inefficient at scale.

Describe the feature you'd like

Add a configurable variable to define the Lambda execution timeout within the template. This would allow centralized configuration rather than manual updates through the AWS Console.

[CrypticCabub]

Thanks for opening this feature request. I highly recommend increasing the lambda runtime size to 512MB as this makes it run substantially faster than the original default of 128MB. You can also further increase to 1024 MB if you need better performance.

According to load testing I performed a few months ago, the most cost-efficient setting for the scheduling lambda is 512MB and setting to 1024 is only slightly less cost efficient but still runs nearly 2x faster (results were something like 2x cost-per-minute but 1.9x faster execution time)