Enhancement : parallel register call to NerdGraph

[wellsiau-aws]

Summary

Currently the solution made call to newrelic_registration in serial fashion. This feature enhancement is to handle multiple registration call simultaneously and removing the dependency from Lambda timeout.

Desired Behaviour

Determine the throttle threshold from NerdGraph and parallelize the registration call, potentially by recursively calling the register Lambda separately (async).

Possible Solution

Add Lambda handler to receive recursive async call for newrelic_registration, handle retries for each parallel call separately, possibly using queue to handle throttle limit from NerdGraph.

Additional context

For use-case of handling large amount of onboarding, instead of increasing the Lambda timeout, split the individual call in parallel.

[wellsiau-aws]

ref to https://boto3.amazonaws.com/v1/documentation/api/latest/reference/services/cloudformation.html#CloudFormation.Client.create_stack_instances

[rohitkaul83]

I think we need to add another issue to invoke "create stack instances" in parallel from the stack set lambda when a large list of existing accounts is passed at launch.