Authors:
- Ayaz Akram
Tasks¶
Introduction¶
The actual gem5 experiment is executed with the help of Celery. Celery server can run many gem5 tasks asynchronously. Once a user creates a gem5Run object (discussed previously) while using gem5art, this object needs to be passed to a method run_gem5_instance() registered with Celery app, which is responsible for starting a Celery task to run gem5. The other argument needed by the run_gem5_instance() is the current working directory. Fundamentally, celery is not required to run gem5 jobs with gem5art and a job can be directly launched by calling run() function of gem5Run object. However, celery can do a better job of managing multiple runs.
Celery server can be started with the following command:
celery -E -A gem5art.tasks.celery worker --autoscale=[number of workers],0
This will start a server with events enabled that will accept gem5 tasks as defined in gem5art. It will autoscale from 0 to desired number of workers.
Celery relies on a message broker RabbitMQ for communication between the client and workers.
If not already installed, you need to install RabbitMQ on your system (before running celery) using:
apt-get install rabbitmq-server
Monitoring Celery¶
Celery does not explicitly show the status of the runs by default. flower, a Python package, is a web-based tool for monitoring and administrating Celery.
To install the flower package,
pip install flower
You can monitor the celery cluster doing the following:
flower -A gem5art.tasks.celery --port=5555
This will start a webserver on port 5555.
Removing all tasks¶
celery -A gem5art.tasks.celery purge
Viewing state of all jobs in celery¶
celery -A gem5art.tasks.celery events
