Description

Similar to #13351 but using the built-in node server for ssr mode as the proxy

• In SSR Mode, node will now launch in front of the python server and not the other way around
• node will proxy requests for static routes to the background workers. node will continue serving the requests for the ssr-related assets as well
• This bypasses the Node proxy in the python server and offers huge speedups
• Working with gr.Server + ZeroGPU (space) and gr.Blocks + ZeroGPU (space)

Architecture

  flowchart TD
      Client[Client / Browser]
      Client --> Node["<b>node :7860</b><br/>reverse proxy"]

      Node -- "/upload, /file=, /static,<br/>/assets, /svelte, /favicon.ico" --> Pool
      Node -- "/queue/*, /api/*, SSE" --> Main
      Node -- "/, /_app/*" --> node

     subgraph Pool["Static Workers (round-robin)"]
          W1["Worker 1 :7862<br/>uploads, downloads, static assets"]
          W2["Worker 2 :7863<br/>uploads, downloads, static assets"]
      end

      Main["<b>Main Server :7861</b><br/>queue, SSE, API, session state, ML inference"]

      Pool --> FS
      Main --> FS
      FS[("Shared filesystem<br/>/tmp/gradio/")]

AI Disclosure

We encourage the use of AI tooling in creating PRs, but the any non-trivial use of AI needs be disclosed. E.g. if you used Claude to write a first draft, you should mention that. Trivial tab-completion doesn't need to be disclosed. You should self-review all PRs, especially if they were generated with AI.

• I used AI to... [fill here]
• I did not use AI

🎯 PRs Should Target Issues

Before your create a PR, please check to see if there is an existing issue for this change. If not, please create an issue before you create this PR, unless the fix is very small.

Not adhering to this guideline will result in the PR being closed.

Testing and Formatting Your Code

1. PRs will only be merged if tests pass on CI. We recommend at least running the backend tests locally, please set up your Gradio environment locally and run the backed tests: bash scripts/run_backend_tests.sh

2. Please run these bash scripts to automatically format your code: bash scripts/format_backend.sh, and (if you made any changes to non-Python files) bash scripts/format_frontend.sh