Celery works without broker and backend running - redis

I'm running Celery on my laptop, with rabbitmq being the broker and redis being the backend. I just used all the default settings and ran celery -A tasks worker --loglevel=info, then it all worked. The workers can get jobs done and I get fetch the execution results by calling result.get(). My question here is that why it works even if I didn't run the rebbitmq and redis servers at all. I did not set the accounts on the servers either. In many tutorials, the first step is to run the broker and backend servers before starting celery.
I'm new to these tools and do not quite understand how they work behind the scene. Any input would be greatly appreciated. Thanks in advance.

Never mind. I just realized that redis and rabbitmq automatically run after installation or shell startup. They must be running for celery to work.

Related

Start redis worker automatically

Am using celery with redis its working fine but problem is to start worker have to give manually.Is there any way to start 'Redis woker' automatically without doing manually
There is a whole section in the Celery documentation about it.

How to track celery and rabbitmq in production server

I have installed both celery and rabbitmq. Now i would like to track how many messages are there in the queue and how it is distributed, want to see the list of celery consumers and tasks they are executing etc. this is bcoz i had issues with celery getting stuck when there is a memory pressure. I tried installing rabbitmq management for a start and when i tried to login at myservr.com:15672 it said can only be used through localhost, is there any workaround? Also is it a good idea to run such monitoring on production servers? Will there be any chance for memory leaks?

Redis still has data after Celery run

I have set up a Celery task that is using RabbitMQ as the broker and Redis as the backend. After running I noticed that my Redis server was still using a lot of memory. Upon inspection I found that there were still keys for each task that was created.
Is there a way to get Celery to clean up these keys only after the response has been received? I know some MessageBrokers use acks, is there an equivalent for a redis backend in Celery?
Yes, use result_expires. Please note that celery beat should run as well, as written in the documentation:
A built-in periodic task will delete the results after this time (celery.backend_cleanup), assuming that celery beat is enabled. The task runs daily at 4am.
Unfortunately Celery doesn't have acks for its backend, so the best solution for my project was to call forget on my responses after I was done with them.

Restarting managed servers by clusters without outage

I want to write script for restarting weblogics managed servers, which would do the following:
It would contain loop ,which would restart first nodes of all clusters at one time.
a.)FORCE_SHUTDOWN
b.)wait for status: SHUTDOWN
c.)START managed servers
d.)wait for status: RUNNING
e.)move to next node of each cluster and repeat until all managed servers are restarted.
So in first iteration it would restart all first nodes of each cluster, in second iteration it would restart the second nodes of each cluster and repeat this action until all managed servers are restarted.
I have not started to writing the script yet, I am newbie with weblogic and this is just concept. Do you have any suggestions how to achieve that goal?
Why reinvent the wheel?
rollingRestart
Category: Control Commands
Use with WLST: Online
Description Initiates a rolling restart of all servers in a domain or all servers in a specific cluster or clusters without interrupting
the service. This command provides the ability to sequentially restart
servers.
This operation involves the graceful shutdown of the servers, and the
servers being restarted without interrupting the service for the user.
Syntax
rollingRestart(target, [options])

RabbitMQ creates a number of strange processes

I happened to find a number of strange processes created by rabbitmq on my RabbitMQ server. I ran rabbitmq server in a docker container. I recreated the container and hours later those processes appeared again. There're some consumers connecting to it. Any idea about what those processes for? Thanks!