Question
Python bokeh with flask and gunicorn err_connection_refused
Hi everyone,
I am trying to set up an bokeh application with flask and gunicorn. I am working on a debian system on an AWS server with the IP 35.XXX.XXX.153. I used the example from git and edited it in the way that I think it should work. The problem is, when I run the gunicorn command (gunicorn3 -w 1 --bind 0.0.0.0:8000 wsgi:app) I get an error in the browser terminal:
(index):30 GET http:// 35.XXX.XXX.153:5006/bkapp/autoload.js?bokeh-autoload-element=4755&bokeh-app-path=/bkapp&bokeh-absolute-url=http:// 35.XXX.XXX.153:5006/bkapp net::ERR_CONNECTION_REFUSED
I have no clue why I get a ERR_CONNECTION_REFUSED.
Here is my code: flaskapp.py
import asyncio
from threading import Thread
from flask import Flask, render_template
from flask_cors import CORS
from tornado.httpserver import HTTPServer
from tornado.ioloop import IOLoop
from bokeh.application import Application
from bokeh.application.handlers import FunctionHandler
from bokeh.client import pull_session
from bokeh.core.validation import silence
from bokeh.core.validation.warnings import FIXED_SIZING_MODE
from bokeh.embed import server_document, autoload_static, server_session
from bokeh.io import curdoc
from bokeh.layouts import column
from bokeh.models import ColumnDataSource, Slider
from bokeh.plotting import figure
from bokeh.sampledata.sea_surface_temperature import sea_surface_temperature
from bokeh.server.server import Server
from bokeh.server.server import BaseServer
from bokeh.server.tornado import BokehTornado
from bokeh.server.util import bind_sockets
from bokeh.themes import Theme
import data.DataHead as DataHead
if __name__ == '__main__':
print('This script is intended to be run with gunicorn. e.g.')
print()
print(' gunicorn -w 4 flask_gunicorn_embed:app')
print()
print('will start the app on four processes')
import sys
sys.exit()
app = Flask(__name__)
CORS(app)
def bkapp(doc):
df = sea_surface_temperature.copy()
source = ColumnDataSource(data=df)
plot = figure(x_axis_type='datetime', y_range=(0, 25), y_axis_label='Temperature (Celsius)',
title="Sea Surface Temperature at 43.18, -70.43")
plot.line('time', 'temperature', source=source)
def callback(attr, old, new):
if new == 0:
data = df
else:
data = df.rolling(f"{new}D").mean()
source.data = ColumnDataSource.from_df(data)
slider = Slider(start=0, end=30, value=0, step=1, title="Smoothing by N Days")
slider.on_change('value', callback)
doc.add_root(column(slider, plot))
doc.theme = Theme(filename="theme.yaml")
bkapp = Application(FunctionHandler(bkapp))
sockets, port = bind_sockets("localhost", 5006)
@app.route('/', methods=['GET'])
def bkapp_page():
script = server_document('http://35.XXX.XXX.153:%d/bkapp' % port)
return render_template("embed.html", script=script, template="Flask")
def bk_worker():
asyncio.set_event_loop(asyncio.new_event_loop())
bokeh_tornado = BokehTornado({'/bkapp': bkapp}, extra_websocket_origins=["*"])
bokeh_http = HTTPServer(bokeh_tornado)
bokeh_http.add_sockets(sockets)
server = BaseServer(IOLoop.current(), bokeh_tornado, bokeh_http)
server.start()
server.io_loop.start()
t = Thread(target=bk_worker)
t.daemon = True
t.start()
from flaskapp import app
if __name__ == "__main__":
app.run()
embed.html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
{{ bokeh_css }}
{{ bokeh_js }}
<link rel="stylesheet" href="./static/css/styles.css" type="text/css"/>
<link rel="shortcut icon" href="./static/favicon/favicon.ico" type="image/x-icon">
</head>
<body>
<div class="head">
<a href="http://"><img src="./static/images/logo.png" width="93px" height="36px"/></a>
</div>
<div class="body">
{{ script|safe }}
</div>
</body>
</html>
On the debian server I forwarded the ports 80, 443, 5006-5015, 5432, 8000, 8080.
Maybe someone has an idea why I am getting this error and how I can resolve it. Thank you!
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Hello NikoD, I’m faced the same problem these days and found that removing "template=“Flask” from render_template helps me.
Hope this helps you too dem865
I got one step further. With the help of bobbys answer and some other changes, it is running now with one worker. Now I would like to change it to 4 workers. So i changed the command to
gunicorn3 -w 4 --bind 0.0.0.0:8000 wsgi:appand as well changed the binded port from 5006 to 0, so it takes a random free port.sockets, port = bind_sockets("0.0.0.0", 0)I need to do that, so that all four workers run on different ports. If I open the application now, I get the following error in the broswer console.Can someone tell me, why I get a time out error? It is working fine with one worker and a set port. Thanks a lot!
I am one step further. I got it running with the help of Bobby and some here and there things.
Now it is running with one worker and a defined port in
bind_sockets("0.0.0.0", 5006). If I want to user 4 workers, I can’t set a port, because they all need different ports. So I changed the port to 0bind_sockets("0.0.0.0", 0), so that it takes a free port. But then I will get an error in the browser console:Can someone help me with that error?