Install python3
> brew install python3> python3 -V # should display the version
Install and run rabbitmq
> brew install rabbitmq> sudo rabbitmq-server # should run the rabbitmq server
# if the rabbitmq-server returns an error like “not_a_dets_file”, then delete the dets file. This is usually due to incorrect shutdown of the rabbitmq-server
> rm /usr/local/var/lib/rabbitmq/mnesia/rabbit\@localhost/recovery.dets
RabbitMQ can now be accessed on localhost:15672
Install celery
> brew install celery> mkdir & cd celery_tasks
> vim tasks.py
from celery import Celery
# first arg is the name to be prepended to the tasks
# backend param is an optional tag to retrieve the status of a backrgound running task
# broker is the broker service that routes the incoming and the outgoing messages
app = Celery('tasks', backend='amqp', broker='amqp://')
# all tasks must be decorated
@app.task(ignore_result=True)
def print_hello():
print ('hello there')
# a task to generate prime numbers that should take time
@app.task
def gen_prime(x):
multiples=[]
results=[]
for i in range(2,x+1):
if i not in multiples:
results.append(i)
for j in range(i*i,x+1,i):
multiples.append(j)
return results
> celery worker -A tasks &
- To run the actual tasks
> python3
> from tasks import print_hello
> from tasks import gen_prime
> print_hello()
> primes=gen_prime(1000)
> print primes
> # to check if the task is complete
> primes.ready()
> # to get the results
> print primes.get()
Install Celery flower
> pip3 install flower> flower —port 5555
> # accessing flower on the port should show the list of active tasks
Celery flower can now be accessed on localhost:5555
