Policy: AWS > Lambda > Function > Allowed Runtime

Determine the action to take when an AWS > Lambda > Function is not using the desired runtime.

The runtimes allowed in your environment are defined in the AWS > Lambda > Function > Allowed Runtime > Values policy.

If this policy is set to Enforce: Upgrade to Target Runtime, functions will be updated to the runtime defined in the AWS > Lambda > Function > Allowed Runtime > Target Runtime policy — even if their current runtime is in the allowed list. Only functions of the same language as the target runtime are updated; other functions are simply checked against the allowed runtimes. Note that changing the runtime may break the function's code; verify your functions are compatible with the target runtime before enabling enforcement.

For any enforcement actions that specify if new, e.g., Enforce: Upgrade to Target Runtime if new, this control will only take the enforcement actions for functions created within the last 60 minutes. A function's creation time is only recorded when the function is created while real-time event handling is enabled; functions recorded by the AWS > Lambda > Function > Discovery control have no creation time and are checked but never acted on.