Flask crashes when static files are served (ProgrammingError: Recursive use of cursors not allowed)

[nlohmann]

When I enable the flask-profiler, the app crashes when files from the static folder are served:

Traceback (most recent call last):
  File "flask\app.py", line 1836, in __call__
    return self.wsgi_app(environ, start_response)
  File "flask\app.py", line 1820, in wsgi_app
    response = self.make_response(self.handle_exception(e))
  File "flask\app.py", line 1403, in handle_exception
    reraise(exc_type, exc_value, tb)
  File "flask\app.py", line 1817, in wsgi_app
    response = self.full_dispatch_request()
  File "flask\app.py", line 1477, in full_dispatch_request
    rv = self.handle_user_exception(e)
  File "flask\app.py", line 1381, in handle_user_exception
    reraise(exc_type, exc_value, tb)
  File "flask\app.py", line 1475, in full_dispatch_request
    rv = self.dispatch_request()
  File "flask\app.py", line 1461, in dispatch_request
    return self.view_functions[rule.endpoint](**req.view_args)
  File "flask_profiler\flask_profiler.py", line 91, in wrapper
    return wrapped(*args, **kwargs)
  File "flask_profiler\flask_profiler.py", line 72, in wrapper
    collection.insert(measurement.__json__())
  File "flask_profiler\storage\sqlite.py", line 128, in insert
    name))
ProgrammingError: Recursive use of cursors not allowed.
Traceback (most recent call last):
  File "flask\app.py", line 1836, in __call__
    return self.wsgi_app(environ, start_response)
  File "flask\app.py", line 1820, in wsgi_app
    response = self.make_response(self.handle_exception(e))
  File "flask\app.py", line 1403, in handle_exception
    reraise(exc_type, exc_value, tb)
  File "flask\app.py", line 1817, in wsgi_app
    response = self.full_dispatch_request()
  File "flask\app.py", line 1477, in full_dispatch_request
    rv = self.handle_user_exception(e)
  File "flask\app.py", line 1381, in handle_user_exception
    reraise(exc_type, exc_value, tb)
  File "flask\app.py", line 1475, in full_dispatch_request
    rv = self.dispatch_request()
  File "flask\app.py", line 1461, in dispatch_request
    return self.view_functions[rule.endpoint](**req.view_args)
  File "flask_profiler\flask_profiler.py", line 91, in wrapper
    return wrapped(*args, **kwargs)
  File "flask_profiler\flask_profiler.py", line 72, in wrapper
    collection.insert(measurement.__json__())
  File "flask_profiler\storage\sqlite.py", line 128, in insert
    name))
ProgrammingError: Recursive use of cursors not allowed.

I first though that this is, because requests to /static are not mentioned in the app routes, but also with a route with return app.send_static_file('index.html') I get the same error. All other routes (none are serving files from static) run fine.

I am using:

• Python 2.7.5
• Flask 0.10.1
• Flask-Profiler 0.5

I am happy to provide more information if needed.

[ssharma94]

Hi nlohmann,
I am facing the same issue. Did you get to resolve the issue?

Thanks
Subhash

[nlohmann]

We could not resolve the issue and decided to stop using Flask Profiler.

[ssharma94]

Oh I am putting a fix and let you know if it works. However, did you get any other open source project to do the same.

[nlohmann]

No, we implemented some profiling ourselves. Nothing fancy, and a plugin like this would be appreciated.

[ragingra]

Was a solution for this problem found? I'm getting something very similar and cant figure it out.

Traceback (most recent call last):
    File "\lib\site-packages\flask\app.py", line 1997, in __call__
        return self.wsgi_app(environ, start_response)
    File "\lib\site-packages\flask\app.py", line 1985, in wsgi_app
        response = self.handle_exception(e)
    File "\lib\site-packages\flask\app.py", line 1540, in handle_exception
        reraise(exc_type, exc_value, tb)
    File "\lib\site-packages\flask\app.py", line 1982, in wsgi_app
        response = self.full_dispatch_request()
    File "\lib\site-packages\flask\app.py", line 1614, in full_dispatch_request
        rv = self.handle_user_exception(e)
    File "\lib\site-packages\flask\app.py", line 1517, in handle_user_exception
        reraise(exc_type, exc_value, tb)
    File "\lib\site-packages\flask\app.py", line 1612, in full_dispatch_request
        rv = self.dispatch_request()
    File "\lib\site-packages\flask\app.py", line 1598, in dispatch_request
        return self.view_functions[rule.endpoint](**req.view_args)
    File "\lib\site-packages\flask_httpauth.py", line 93, in decorated
        return f(*args, **kwargs)
    File "\lib\site-packages\flask_profiler\flask_profiler.py", line 212, in getRequestsTimeseries
        return jsonify({"series": collection.getTimeseries(args)})
    File "\lib\site-packages\flask_profiler\storage\sqlite.py", line 158, in getTimeseries
        self.cursor.execute(sql)
ProgrammingError: Recursive use of cursors not allowed.

[iurisilvio]

The problem here is with a shared sqlite3 cursor.

flask-profiler/flask_profiler/storage/sqlite.py

Line 33 in b9d4b7a

self.cursor = self.connection.cursor()

https://stackoverflow.com/questions/26629080/python-and-sqlite3-programmingerror-recursive-use-of-cursors-not-allowed

If this is the reason, using another storage will fix the problem.

[AbdealiLoKo]

FWIW, I was using flask-profiler 1.7 all this while and didnt face an issue for a year. I just moved to 1.8.1 and am seeing it multiple times.

[dzpt]

same to me. error on 1.8.1, but works fine on 1.7