Redis-Celery/README.md

Redis-Celery (Distributed Architecture)

This includes

• Redis
• Flower

Usage (docker-compose)

• start the system
  docker-compose up add -d run in background
  
• down the system
  ctrl-c or
  docker-compose down
  

Celery

Celery Documentation
Flower Documentation

install Celery

pip install -U "celery[redis]" 

Starting the worker

celery -A proj worker 

Options

''' Worker Options: -n, --hostname HOSTNAME Set custom hostname (e.g., 'w1@%%h').

                              Expands: %%h (hostname), %%n (name) and %%d, (domain).  

-D, --detach Start worker as a background process.
-S, --statedb PATH Path to the state database. The extension

                              '.db' may be appended to the filename.  

-l, --loglevel [DEBUG|INFO|WARNING|ERROR|CRITICAL|FATAL]

                              Logging level.  

-O, --optimization [default|fair]

                              Apply optimization profile.  

--prefetch-multiplier

                              Set custom prefetch multiplier value for  
                              this worker instance.  

Pool Options:

• -c, --concurrency
  Number of child processes processing the
  queue. The default is the number of CPUs
  available on your system.
  ''' '''celery worker --help''' can get more infomation.
  

woker in Windows

add --pool=solo option

Calling the task

>>> from tasks import hello
>>> hello.delay()

If your celery app set rsult backend

>>> from tasks import hello  
>>> result = hello.delay()

The ready() method returns whether the task has finished processing or not:

>>> result.ready()
>>> False

You can wait for the result to complete, but this is rarely used since it turns the asynchronous call into a synchronous one:

>>> result.get(timeout=1)
>>> 'hello world'