Quickstart

Basic usage

You can run CATS with:

A basic command to run CATS when a job duration and postcode are provided.

$ python -m cats -d <job_duration> --loc <postcode>

The postcode is optional, and can be pulled from the config.yml file or, if that is not present, inferred using the server IP address.

The job_duration is in minutes, specified as an integer.

The scheduler then calls a function that estimates the best time to start the job given predicted carbon intensity over the next 48 hours. The workflow is the same as for other popular schedulers. Switching to CATS should be transparent to cluster users.

It will display the time to start the job on standard out and optionally some information about the carbon intensity on standard error.

Displaying carbon footprint estimates

CATS is able to provide an estimate for the carbon footprint reduction resulting from delaying your job. To enable the footprint estimation, you must provide information about the machine in the form of a YAML configuration file. An example is given below:

An example provision of machine information by YAML file to enable estimation of the carbon footprint reduction.

cluster_name: "CW23"
postcode: "EH8 9BT"
PUE: 1.20 # > 1
partitions:
  CPU_partition:
    type: CPU # CPU or GPU
    model: "Xeon Gold 6142"
    TDP: 9.4 # Thermal Design Power, in W per core
  GPU_partition:
    type: GPU
    model: "NVIDIA A100-SXM-80GB GPUs"
    TDP: 300 # from https://www.nvidia.com/content/dam/en-zz/Solutions/Data-Center/a100/pdf/PB-10577-001_v02.pdf
    CPU_model: "AMD EPYC 7763"
    TDP_CPU: 4.4 # from https://www.amd.com/fr/products/cpu/amd-epyc-7763

Use the --config option to specify a path to the configuration file, relative to the current directory. If no path is specified, CATS looks for a file named config.yml in the current directory.

Additionally, to obtain carbon footprints, job-specific information must be provided to CATS through the --jobinfo option. The example below demonstrates running CATS with footprint estimation for a job using 8GB of memory, 2 CPU cores and no GPU:

An example run command showing provision of job information.

$ cats -d 120 --config .config/config.yml --jobinfo cpus=2,gpus=0,memory=8,partition=CPU_partition