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Feature request: Priming for powertools-tracing #2004

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#2345
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Feature request: Priming for powertools-tracing#2004
#2345
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Attyuttam
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feature-requestNew feature or requestgood-first-issueGood for newcomershelp-wanted

Description

@phipag
phipag
opened on Aug 4, 2025

Use case

PLEASE READ: Priming documentation: https://github.com/aws-powertools/powertools-lambda-java/blob/main/Priming.md

Parent issue: #1588
Sample PR: #1861

Java CRaC can be used to prime an application by implementing beforeCheckpoint() and afterRestore() hooks in selected classes. When used with AWS Snapstart, the beforeCheckpoint() hook runs before the memory snapshot is taken. This behavior can be leveraged to further reduce restore durations by pre-loading classes and calling commonly used code to incorporate this into the memory snapshot.

  1. Class-preloading / automatic priming: Based on a statically generated classesloaded.txt file, loads classes used at runtime into memory
  2. Invoke priming: Execute commonly used code e.g. to initialize all reflectively access objects, warm up caches, TCP connection pools etc. Common examples include performing "dry" AWS SDK calls (not impacting production resources) or performing JSON serialization/deserialization.

The goal of this issue is to implementing priming techniques for the powertools-tracing module.

Solution/User Experience

Implement priming based on Priming Documentation (feel free to update documentation and suggest improvements):

  • Automatic priming
  • Invoke priming

Alternative solutions



Acknowledgment



Future readers


Please react with 👍 and your use case to help us understand customer demand.
Activity
  1. phipag
    added 
    feature-requestNew feature or request
     
    triage
     on Aug 4, 2025
  2. github-project-automation
    added this to  Powertools for AWS Lambda (Java)on Aug 4, 2025
  3. github-project-automation
    moved this to Triage in  Powertools for AWS Lambda (Java)on Aug 4, 2025
  4. phipag
    added a parent issue on Aug 4, 2025
  5. phipag
    moved this from Triage to Backlog in  Powertools for AWS Lambda (Java)on Aug 4, 2025
  6. phipag
    added 
    good-first-issueGood for newcomers
     
    help-wanted
     and removed 
    triage
     on Aug 4, 2025
  7. dcabib commented on Aug 29, 2025 
    @dcabib
    dcabib
    on Aug 29, 2025
    Hi @phipag! 👋
    

    I'd be happy to help implement priming support for the powertools-tracing module. I've reviewed the priming documentation and the reference implementation in powertools-metrics, and I have a good understanding of what needs to be done.
    

    My proposed implementation approach:
    

      

    1. 

      Add Maven profile to powertools-tracing/pom.xml for generating the classes loaded file (similar to the generate-classesloaded-file profile in powertools-metrics)
      

      2. 

    2. 

      Generate and clean up the classesloaded.txt file by:
      

        

      • Running tests with the VM argument -Xlog:class+load=info:classesloaded.txt
        • 

      • Processing the file to extract only the fully qualified class names
        • 

      • Moving it to src/main/resources/
        • 

      

      3. 

    3. 

      Implement CRaC Resource interface in TracingUtils class (as the main entry point for the tracing module) by:
      

        

      • Adding CRaC dependency and imports
        • 

      • Registering with Core.getGlobalContext() in a static block
        • 

      • Implementing beforeCheckpoint() to call ClassPreLoader.preloadClasses()
        • 

      • Adding any tracing-specific initialization (like initializing X-Ray components)
        • 

      

      4. 

    4. 

      Test the implementation to ensure it works correctly with SnapStart
      

      5. 

    

    I notice that TracingUtils is the main utility class that users interact with, making it a suitable candidate for CRaC integration, similar to how MetricsFactory is used in the metrics module.
    

    Would you like me to proceed with this implementation? I can start with creating a PR that follows the same pattern as the metrics module implementation.
    

    Also, are there any specific tracing-related initializations you'd recommend including in the beforeCheckpoint() hook beyond the standard class preloading?
    

    Thanks for creating this issue and making it accessible to new contributors! 🚀
  8. phipag commented on Sep 1, 2025 
    @phipag
    phipag
    on Sep 1, 2025
    ContributorAuthor
    Hey @dcabib,
    

    thanks for your detailed implementation plan. I think it makes sense to include the Priming logic in TracingUtils. Just a note: It is possible to use only @Tracing annotation and since this is an AspectJ aspect it does not trigger the CRaC hooks if it calls TracingUtils transitively. We need to update the documentation with guidance that the user needs to reference TracingUtils directly in their code to trigger SnapStart priming.
    

    We did the same thing for ValidationConfig in this PR: #2081.
    

    Regarding what to prime:
    

      

    • Class pre-loading
      • 

    • Invoke priming of AWS SDK. You can prime the X-RAY SDK by performing some dummy calls but need to make sure that no traces are persisted in X-RAY which will incur a cost to the user. Ideally you can make some requests that do not have any persistent side-effects.
      • 

    

    Let me know if you have any questions. Should I assign the issue to you to work on it?
  9. dcabib commented on Sep 1, 2025 
    @dcabib
    dcabib
    on Sep 1, 2025
    Hi @phipag!
    

    Thanks for the feedback and clarifications! I understand the important point about users needing to reference TracingUtils directly to trigger SnapStart priming, and I'll make sure to update the documentation accordingly.
    

    I'm ready to work on this implementation following the patterns established in the metrics module and the ValidationConfig approach from PR #2081. I'll focus on:
    

      

    • Class pre-loading via TracingUtils
      • 

    • Invoke priming of X-Ray SDK with dummy calls that don't persist traces
      • 

    • Proper documentation updates about direct TracingUtils usage
      • 

    

    Please assign this issue to me and I'll get started on the implementation.
    

    Thanks!
  10. phipag
    assigned 
    dcabib
    on Sep 1, 2025
  11. phipag
    moved this from Backlog to Working on it in  Powertools for AWS Lambda (Java)on Sep 1, 2025
  12. phipag commented on Sep 1, 2025 
    @phipag
    phipag
    on Sep 1, 2025
    ContributorAuthor
    That's awesome @dcabib. I assigned the issue to you 🚀
  13. dcabib
    added 3 commits that reference this issue on Sep 1, 2025
    feat: Support CRaC priming for powertools-tracing and powertools-seri…
    eea14d7
    feat: Support CRaC priming for powertools-tracing
    284309b
    feat: Support CRaC priming for powertools-tracing
    786a16a
  14. phipag
    unassigned 
    dcabib
    on Sep 29, 2025
  15. phipag
    moved this from Working on it to Backlog in  Powertools for AWS Lambda (Java)on Sep 29, 2025
  16. phipag commented on Sep 29, 2025 
    @phipag
    phipag
    on Sep 29, 2025
    ContributorAuthor
    This issue is in the backlog again and open for contribution.
  17. Attyuttam commented on Nov 25, 2025 
    @Attyuttam
    Attyuttam
    on Nov 25, 2025
    Contributor
    Hi, I would like to pick this up
  18. Attyuttam commented on Dec 22, 2025 
    @Attyuttam
    Attyuttam
    on Dec 22, 2025
    Contributor
    @phipag can you please have a look at my PR. I have made the changes to the best of my understanding, so it would be great if you could suggest any more changes if needed.
  19. phipag commented on Dec 22, 2025 
    @phipag
    phipag
    on Dec 22, 2025
    ContributorAuthor
    Thanks @Attyuttam, let's continue the conversation in the PR.
  20. Attyuttam commented on Jan 19, 2026 
    @Attyuttam
    Attyuttam
    on Jan 19, 2026
    Contributor
    @phipag i think we can close this issue as it has been addressed in this PR: #2345
  21. phipag
    linked a pull request that will close this issuefeat(crac): Support CRaC and priming of powertools tracing #2345on Jan 19, 2026
  22. phipag commented on Jan 19, 2026 
    @phipag
    phipag
    on Jan 19, 2026
    ContributorAuthor
    You are right @Attyuttam, I missed this! Thanks!
  23. phipag
    closed this as completedon Jan 19, 2026
  24. phipag
    assigned 
    Attyuttam
    on Jan 19, 2026
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