APScheduler duplicating jobs in Flask app hosted on Heroku - flask

Question

I have an app structured as below which allows a user to schedule tasks to query FB API each morning, afternoon etc to pull page/post data (3am in this case).
The problem I am experiencing is that the scheduler is executing each job twice which is obviously undesirable. Oddly, the issue doesn’t seem to occur locally, only when in production mode and I am hosting this in Heroku with 1 web dyno and 1 worker dyno, each with only 1 process each. I am therefore leaning towards Heroku being the issue.
I have a page to list the current scheduled jobs and when I inspect it, upon refreshing the page the same job instance will flick between two different values (screenshot below). It is as if there are two BackgroundScheduler's instances running.
I suspected this was to do with the BackgroundScheduler being initiated twice (once in flasky.py and again in tasks.py) so I created a temporary solution to stop the double initialising of the BackgroundScheduler and I still experience the same issue and am now stuck. Any help would be much appreciated.
-->app
-->__init__.py
-->decorators.py
-->models.py
-->tasks.py
-->auth
-->__init__.py
-->errors.py
-->forms.py
-->views.py
-->main
-->__init__.py
-->errors.py
-->forms.py
-->views.py
-->static
-->templates
-->migrations
config.py
flasky.py
Procfile
requirements.txt
app/flasky.py
from flask import Flask,render_template, session, redirect, url_for, flash
import os
from app import create_app,db
from app.models import User,Role
from datetime import datetime
from flask_migrate import Migrate,upgrade
app = create_app(os.getenv('FLASK_CONFIG') or 'default')
app/_ init _.py
from flask import Flask, render_template
from flask_bootstrap import Bootstrap
from flask_moment import Moment
from flask_migrate import Migrate
from flask_sqlalchemy import SQLAlchemy
from config import config
from flask_session import Session
from apscheduler.schedulers.background import BackgroundScheduler
from apscheduler.jobstores.sqlalchemy import SQLAlchemyJobStore
import rq
from redis import Redis
from flask_login import LoginManager
from worker import conn
import os
bootstrap = Bootstrap()
moment = Moment()
db = SQLAlchemy()
scheduler = BackgroundScheduler()
migrate = Migrate()
session= Session()
login_manager = LoginManager()
login_manager.login_view = 'auth.login'
def create_app(config_name='default'):
app = Flask(__name__)
app.config.from_object(config[config_name])
db.init_app(app)
bootstrap.init_app(app)
moment.init_app(app)
migrate.init_app(app,db)
session.init_app(app)
login_manager.init_app(app)
if not scheduler.running:
scheduler.start()
jobstore_url = os.environ.get('DATABASE_URL')
scheduler.add_jobstore(SQLAlchemyJobStore(url=jobstore_url),'sqlalchemy')
from .main import main as main_blueprint
from .auth import auth as auth_blueprint
app.register_blueprint(main_blueprint)
app.register_blueprint(auth_blueprint,url_prefix='/auth')
app.task_queue = rq.Queue('flasky',connection=Redis.from_url(os.environ.get(REDIS_URL))
if app.config['SSL_REDIRECT']:
from flask_sslify import SSLify
sslify = SSLify(app)
return app
app/tasks.py
from . import create_app,db
from .models import User,Tokens,Files
from .decorators import token_getter
from flask_login import current_user
import requests
import datetime as dt
import urllib
import os
app = create_app(os.getenv('FLASK_CONFIG') or 'default')
<FUNCTIONS HERE>
app/auth/views.py
from flask import render_template,url_for,redirect,request,flash,session,current_app,Response
from .. import db,scheduler
from . import auth
from ..models import User,Role,Tokens,Files
from flask_login import login_user, logout_user, login_required
from ..decorators import admin_required, token_setter, token_getter,permission_required
import requests
import urllib
from .forms import LoginForm, SubmitConnection, ScheduleJobForm
from app.tasks import refreshed_google_client,test_context
app/main/views.py
from flask import render_template, session, redirect, url_for, flash,current_app,request
from datetime import datetime
from . import main
from .. import db,scheduler
from ..models import User,Tokens
from .forms import NameForm,AnalyticsForm
from flask_login import login_required,current_user
from ..decorators import admin_required,permission_required
import requests
import rq
from redis import Redis
from app.tasks import refreshed_google_client,load_analytics
#main.route('/ig_sync',methods=['GET','POST'])
#login_required
#permission_required(4)
def ig_sync():
form = IGAnalyticsForm()
if request.method=='POST':
from app.tasks import load_ig_sync
if form.validate_on_submit():
if form.submit_analytics_schedule.data:
#GET VARIABLES FROM FORM
scheduler.add_job(func=load_ig_sync,args=[#VARIABLES HERE],trigger='cron',hour=3,id=f'SYNC_IG_{page_name}',jobstore='sqlalchemy')
return(redirect(url_for('main.job_schedule')))
return render_template('ig_sync.html',form=form)
app/Procfile
web: gunicorn flasky:app
worker: rq worker -u $REDIS_URL flasky