add docs for post API

[harshit-anyscale]

• adding docs for POST API, here are more details: https://docs.google.com/document/d/1KtMUDz1O3koihG6eh-QcUqudZjNAX3NsqqOMYh3BoWA/edit?tab=t.0#heading=h.2vf4s2d7ca46

• also, making changes for the external scaler enabled in the existing serve application docs

to be merged after #57554

[gemini-code-assist]

Code Review

This pull request adds documentation for the new External Scaling Webhook feature. The new documentation page provides a good overview, API reference, and a Python example. I've suggested a couple of improvements to the example code to make it more robust by adding a request timeout and using a more general success check. The other changes to index and config files look good.

[angelinalg]

Cool feature!

[abrarsheikh]

my high level feedback

1. this content should be part of https://docs.ray.io/en/master/serve/advanced-guides/advanced-autoscaling.html, specifically after Custom autoscaling policies. This will make it easier to tie a story around external scaler and why its needed.
2. The document is too verbose and can be condensed.

[abrarsheikh]

can you confirm that the example work if I try to run it as is following the documentation?

[harshit-anyscale]

@cursoragent can you please fix the unresolved review comments on the latest changes?

[cursor]

Perfect! I've successfully addressed all the unresolved review comments on your PR. Here's a summary of the changes I made:

Changes Made:

1. Fixed bug in external_scaler_predictive_client.py

• Added validation to check if get_current_replicas() returns -1 (error condition)
• The function now returns early with an error log instead of attempting to scale with invalid data

2. Updated config.md

• Changed "webhook" to "API" in the external_scaler_enabled description
• Added a reference link to the External Scaling API section for more details

3. Restructured External Scaling API section in advanced-autoscaling.md

• Updated the introductory description to match the suggested text
• Consolidated "Enable external scaler" and "API endpoint" sections into the "Example: Predictive scaling" section
• Moved configuration and API usage details into the example flow for better organization
• Added the (serve-external-scale-api)= anchor label for cross-referencing

4. Fixed relative path references

• Changed absolute URLs (https://docs.ray.io/...) to relative paths (../api/doc/...) for:
  • ScaleDeploymentRequest schema reference
  • ServeInstanceDetails schema reference
• This makes the references consistent with the rest of the documentation

All review comments have been addressed, and the documentation is now more organized with proper cross-references and consolidated information flow.

---

 

_{Learn more about Cursor Agents}

[angelinalg]

Is this trailing backslash intentional?

[harshit-anyscale]

yes

[github-actions]

This pull request has been automatically marked as stale because it has not had
any activity for 14 days. It will be closed in another 14 days if no further activity occurs.
Thank you for your contributions.

You can always ask for help on our discussion forum or Ray's public slack channel.

If you'd like to keep this open, just leave any comment, and the stale label will be removed.