Requests fail in a simple py4web app running on a paid PythonAnywhere account

[Aubrey Moore]

Not sure if this is a py4web problem or a PythonAnywhere problem, but I would really
appreciate any advice on debugging/fixing it.

I built a very simple py4web app on PythonAnywhere using the Minimal app template.
It is hosted on my paid PA account at aubreymoore.pythonanywhere.com/minimal
When I request the "index" route, I get the expected result, "Hello World".
However, when I request "test_req" or "test_urllib", the browser hangs for about
ten minutes and then returns "Something went wrong :-( ... Error code: 504-loadbalancer".
There are no records added to the PA error log, but the PA server log indicates that
the app commits harakiri and dies after announcing loyalty to the emporer (See below.)

minimal/__init__.py

from py4web import action
import requests
import urllib.request

@action("index")
def index():
    return "Hello World"
   
@action('test_req')
def test_req():
    return requests.get('https://pythonanywhere.com').text
   
@action('test_urllib')
def test_urllib():
    return urllib.request.urlopen("http://pythonanywhere.com").read()

PythonAnywhere Server log

2020-10-17 00:19:50 announcing my loyalty to the Emperor...
2020-10-17 00:26:03 Sat Oct 17 00:26:02 2020 - *** HARAKIRI ON WORKER 2 (pid: 15, try: 1) ***
2020-10-17 00:26:03 Sat Oct 17 00:26:02 2020 - HARAKIRI !!! worker 2 status !!!
2020-10-17 00:26:03 Sat Oct 17 00:26:02 2020 - HARAKIRI [core 0] 10.0.0.124 - GET /minimal/test_urllib since 1602894061
2020-10-17 00:26:03 Sat Oct 17 00:26:02 2020 - HARAKIRI !!! end of worker 2 status !!!
2020-10-17 00:26:03 DAMN ! worker 2 (pid: 15) died, killed by signal 9 :( trying respawn ...
2020-10-17 00:26:03 Respawned uWSGI worker 2 (new pid: 18)
2020-10-17 00:26:03 spawned 2 offload threads for uWSGI worker 2

[Abdoul salam]

I've had similar problem few months back. Seems not supported for now and no one will want to talk about. Even the SMTP wasn't working. 

My advice:

If your project has a deadline, port back to web2py till it becomes a priority

[Massimo]

I tried this on my python anywhere account:

mkdir apps

mkdir apps/test

echo "" > apps/__init__.py

echo > apps/test/__init__.py << EOF

from py4web import action

import requests

import urllib.request

@action("index")

def index(): return "Hello World\n"

@action('test_requests')

def test_req(): return requests.get('https://pythonanywhere.com').text

@action('test_urllib')

def test_urllib(): return urllib.request.urlopen("http://pythonanywhere.com").read()

EOF

py4web run apps --port 8001 > apps.log

curl http://127.0.0.1:8001/test > 1.txt

curl http://127.0.0.1:8001/test/test_requests > 2.txt

curl http://127.0.0.1:8001/test/test_urllib > 3.txt

It worked fine. Can you try on yours?

[Aubrey Moore]

Sorry for being such a newbie.

Working in a bash console, everything goes fine until I launch the server:

command: py4web run apps --port 8001 > apps.log

response: .. Listening on http://127.0.0.1:8001/

When I enter:

curl http://127.0.0.1:8001/test > 1.txt

Nothing happens.

When I open a new bash console and re-enter the curl command, I get:

Failed to connect to 127.0.0.1 port 8001: Connection refused

What am I missing?

--
You received this message because you are subscribed to the Google Groups "py4web" group.
To unsubscribe from this group and stop receiving emails from it, send an email to py4web+un...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/py4web/fdc6cccf-4e7c-4c9d-9a02-c80bdda9da86n%40googlegroups.com.

[Massimo DiPierro]

curl http://127.0.0.1:8001/test > 1.txt

will create a file 1.txt and it should contain the web page.

Let me know if it does or not.

It may be ok that does not work from another console. Different consoles may run on different vms.

[Abdoul salam]

SMTP!!! 

Error Ticket: database is locked

Traceback (most recent call last): File "/home/halal/.virtualenvs/venv/lib/python3.7/site-packages/py4web/core.py", line 734, in wrapper ret = func(*func_args, **func_kwargs) File "/home/halal/.virtualenvs/venv/lib/python3.7/site-packages/py4web/core.py", line 694, in wrapper ret = func(*args, **kwargs) File "/home/halal/.virtualenvs/venv/lib/python3.7/site-packages/py4web/core.py", line 694, in wrapper ret = func(*args, **kwargs) File "/home/halal/.virtualenvs/venv/lib/python3.7/site-packages/py4web/utils/auth.py", line 677, in _ return dict(form=form_factory(), path=path, **env) File "/home/halal/.virtualenvs/venv/lib/python3.7/site-packages/py4web/utils/auth.py", line 942, in request_reset_password self.auth.request_reset_password(email, send=True, next="") File "/home/halal/.virtualenvs/venv/lib/python3.7/site-packages/py4web/utils/auth.py", line 410, in request_reset_password user.update_record(action_token="reset-password-request:" + token) File "/home/halal/.virtualenvs/venv/lib/python3.7/site-packages/pydal/helpers/classes.py", line 361, in __call__ table._db(table._id == id, ignore_common_filters=True).update(**newfields) File "/home/halal/.virtualenvs/venv/lib/python3.7/site-packages/pydal/objects.py", line 2699, in update ret = db._adapter.update(table, self.query, row.op_values()) File "/home/halal/.virtualenvs/venv/lib/python3.7/site-packages/pydal/adapters/base.py", line 586, in update raise e File "/home/halal/.virtualenvs/venv/lib/python3.7/site-packages/pydal/adapters/base.py", line 581, in update self.execute(sql) File "/home/halal/.virtualenvs/venv/lib/python3.7/site-packages/pydal/adapters/__init__.py", line 69, in wrap return f(*args, **kwargs) File "/home/halal/.virtualenvs/venv/lib/python3.7/site-packages/pydal/adapters/base.py", line 468, in execute rv = self.cursor.execute(command, *args[1:], **kwargs) sqlite3.OperationalError: database is locked

[Val K]

  check for  `db.commit()` in your models files and controllers - py4web does not call it automatically  

пятница, 30 октября 2020 г. в 12:49:03 UTC+3, ibraheema...@gmail.com:

[Abdoul salam]

Thanks. It helps. now i have this.

[Nico Zanferrari]

Hi,

I've tested it with a free PA account that uses python 3.8.0 by default, and this works fine from the Bash [note that you have to start py4web in the background in order to be able to use the same console, i.e : py4web run apps --port 8001  & > apps.log]

But, as I've expected, when you run the same app inside py4web as a web application within the PA framework, it does not work. Specifically: 

http://your_account.pythonanywhere.com/test --> OK

http://your_account.pythonanywhere.com/test/test_requests --> HANG

http://your_account.pythonanywhere.com/test/test_urllib --> HANG

I have no idea on how to debug this issue ;-(

Nico

To view this discussion on the web visit https://groups.google.com/d/msgid/py4web/1172A7B0-59E2-4815-BACE-F63ABFAB0AB6%40gmail.com.

[Massimo DiPierro]

As an experiment. Can you try comment monkey.patch_all() ?

To view this discussion on the web visit https://groups.google.com/d/msgid/py4web/CAAE8D_By7jUPiyRM1VpTQanhuSZKcnmRhw%2BKCfv6KkHQ%3Di-FRQ%40mail.gmail.com.

[Nico Zanferrari]

I've just tried by commenting the line in core.py (   #gevent.monkey.patch_all()). 

Now:

http://your_account.pythonanywhere.com/test --> OK

http://your_account.pythonanywhere.com/test/test_requests --> 404 NOT FOUND

http://your_account.pythonanywhere.com/test/test_urllib --> 404 NOT FOUND

Maybe I should try an update to the latest version, this is "1.20200911.2"

Nico

[Val K]

It seems that it is uWSGI issue (I suppose It also patches something), 

I moved monkey.patch_all to the PA-wsgi-script  (as "Patching should be done as early as possible" - see http://www.gevent.org/api/gevent.monkey.html)

but it doesnt solve the problem - requests doesnt work.

But if I just run python from bash console and do this:

from gevent import monkey

monkey.patch_all()

import requests 

requests.get('https://google.com')  

- that works fine 

Also, I tested requests on my server nginx+gunicorn  - works fine (with monkey.patch_all() )

среда, 4 ноября 2020 г. в 19:06:40 UTC+3, nico...@gmail.com:

[Massimo]

I tested this and if I comment gevent.monkey.patch_all() from core.py, then pythonanywhere requests works fine for me. gevent is also a problem on google app engine and we are not using it unless we have multiple workers. For now I have eliminated this dependency and picked tornado as default.

Can you please confirm this works for you? Thoughts?

I am not sure this is the best solutions. The reason gevent is there is that I was planning to add websockets support and they works better with gevent than Tornado in my experience. Yet we are not using any async feature at this time.

Massimo

[Val K]

We can just set some os/wsgi env variable at PA starting script ( or use some existing  to detect that it is uwsgi/PA) before import py4web and then check it in core.py before patching

понедельник, 30 ноября 2020 г. в 01:58:03 UTC+3, Massimo:

[Nico Zanferrari]

Hi Massimo,

I do confirm that with the latest version (with the gevent removal) the problem has been resolved. I'm sorry that I've previously reported that it was not working - maybe I'd forgotten to reload the web app....

Anyhow, this is working fine now, and I can also report that the SMTP problem has gone, too, even with the free account ;-) I'm adding a note to Issue #288.

As a little side effect of gevent removal is on Windows, where the Ctrl-C key sequence does not work anymore to stop the bottle web server: you need to send Ctrl-Break. But this is just annoying.

Thanks a lot,

Nico

To view this discussion on the web visit https://groups.google.com/d/msgid/py4web/fd48c7f4-1b6d-4415-921d-13355e68fb85n%40googlegroups.com.

[Massimo]

yes. it is annoying. Have any idea how to resolve it?

[Massimo]

To be clear. It works fine without gevent and currently py4web is not using gevent.