[17.0] fastapi: Production outages: RuntimeError

[JochenVanSeveren]

Module

fastapi

Describe the bug

2025-03-27 11:15:26,319 13776 ERROR my-odoo-instance odoo.http: Exception during request handling. 
Traceback (most recent call last):
  File "/home/odoo/src/odoo/odoo/tools/cache.py", line 99, in lookup
    r = d[key]
  File "<decorator-gen-5>", line 2, in __getitem__
  File "/home/odoo/src/odoo/odoo/tools/func.py", line 87, in locked
    return func(inst, *args, **kwargs)
  File "/home/odoo/src/odoo/odoo/tools/lru.py", line 34, in __getitem__
    a = self.d[obj]
KeyError: ('fastapi.endpoint', <function FastapiEndpoint.get_app at 0x7fbe3e2e2710>, '/app')

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/odoo/src/odoo/odoo/http.py", line 2213, in __call__
    response = request._serve_db()
  File "/home/odoo/src/odoo/odoo/http.py", line 1788, in _serve_db
    return service_model.retrying(self._serve_ir_http, self.env)
  File "/home/odoo/src/odoo/odoo/service/model.py", line 152, in retrying
    result = func()
  File "/home/odoo/src/odoo/odoo/http.py", line 1816, in _serve_ir_http
    response = self.dispatcher.dispatch(rule.endpoint, args)
  File "/home/odoo/src/user/OCA/rest-framework/extendable_fastapi/fastapi_dispatcher.py", line 19, in dispatch
    return super().dispatch(endpoint, args)
  File "/home/odoo/src/user/OCA/rest-framework/fastapi/fastapi_dispatcher.py", line 28, in dispatch
    app = fastapi_endpoint.get_app(root_path)
  File "<decorator-gen-126>", line 2, in get_app
  File "/home/odoo/src/odoo/odoo/tools/cache.py", line 104, in lookup
    value = d[key] = self.method(*args, **kwargs)
  File "/home/odoo/src/user/OCA/rest-framework/fastapi/models/fastapi_endpoint.py", line 216, in get_app
    return ASGIMiddleware(app)
  File "/home/odoo/.local/lib/python3.10/site-packages/a2wsgi/asgi.py", line 131, in __init__
    loop_threading.start()
  File "/usr/lib/python3.10/threading.py", line 935, in start
    _start_new_thread(self._bootstrap, ())
RuntimeError: can't start new thread

To Reproduce

This occured a couple of times already in production and the error repeats itself untill the server is restarted.

Additional context
Let me know if additional context is needed.

[sbidoul]

Maybe this is #484

[JochenVanSeveren]

Thank you Stéphane. Seems it could be the case.
It's quite hard to tell any resource induced outages the Odoo.sh monitoring tab. Then again, it's not that accurate of a tool.

How can I help merge #486 into 17.0? My knowledge doesn't go further then basic threads. Not afraid to give it a shot though.