Add CloudFormation parameter to control Lambda X-Ray tracing (default to PassThrough)

[nirajguru]

Description

The current Instance Scheduler stacks do not expose a CloudFormation parameter to control AWS X-Ray tracing for the solution’s Lambda functions. As a result, tracing behavior is fixed and cannot be adjusted by customers via stack parameters. There is a non-trivial ongoing cost associated with X-Ray, and customers should be able to choose whether to enable it.

Per AWS CloudFormation, Lambda X-Ray tracing is controlled via:
https://docs.aws.amazon.com/AWSCloudFormation/latest/TemplateReference/aws-properties-lambda-function-tracingconfig.html

The solution should allow configuration of tracing and default to PassThrough (disabled) to avoid unexpected cost for users who do not require X-Ray.

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Impact

• Cost control: X-Ray adds per-trace sampling, storage, and retrieval costs. Defaulting to PassThrough avoids unintended charges.
• Operational flexibility: Some environments prohibit tracing or require explicit opt-in.
• Consistency: Aligns with best practices to disable optional observability features by default and allow opt-in via parameters.

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Expected Behavior

• All Lambda functions in the Instance Scheduler solution respect a new CloudFormation parameter (e.g., EnableXRayTracing) to toggle tracing.
• When the parameter is disabled (default), all Lambda TracingConfig.Mode values are set to PassThrough.
• When enabled, all Lambda TracingConfig.Mode values are set to Active.

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Actual Behavior

• No CloudFormation parameter exists to control X-Ray tracing.
• Tracing configuration cannot be easily changed post-deployment without template edits.

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Proposal

Add parameter to control X-ray tracing

Parameters:
  EnableXRayTracing:
    Type: String
    AllowedValues:
      - Enabled
      - Disabled
    Default: Disabled
    Description: >
      Controls AWS X-Ray tracing for all solution Lambda functions.
      Set to Enabled to use TracingConfig.Mode=Active. Disabled uses PassThrough.

and apply to Lambda function resource

Mappings:
  XRayTracingModeMap:
    Enabled:
      Mode: Active
    Disabled:
      Mode: PassThrough

Resources:
  SchedulerFunction:
    Type: AWS::Lambda::Function
    Properties:
      # ... existing properties ...
      TracingConfig:
        Mode: !FindInMap [ XRayTracingModeMap, !Ref EnableXRayTracing, Mode ]

[CrypticCabub]

Thank you for this feature request. We will add it to our backlog for consideration

[CrypticCabub]

@nirajguru

Do you have any metrics that indicate that x-ray provides any notable costs to the operation of instance scheduler? generally in cost estimations I have not seen x-ray be much of a cost driver for the solution's monthly operating costs.

[whoDoneItAgain]

I will pose a different but similar question. Should X-ray be removed? With the recent depreciation announcement it may make more sense to go that way. We have about 14 months before it's EOS. https://docs.aws.amazon.com/xray/latest/devguide/xray-daemon-eos.html