Disable file output of hydra

Question

I'm using hydra to log hyperparameters of experiments.

@hydra.main(config_name="config", config_path="../conf")
def evaluate_experiment(cfg: DictConfig) -> None:
    print(OmegaConf.to_yaml(cfg))
    ...

Sometimes I want to do a dry run to check something. For this I don't need any saved parameters, so I'm wondering how I can disable the savings to the filesystem completely in this case?

Answer 1

There is an enhancement request aimed at Hydra 1.1 to support disabling working directory management. Working directory management is doing many things:

• Creating a working directory for the run
• Changing the working directory to the created dir.

There are other related features:

• Saving log files
• Saving files like config.yaml and hydra.yaml into .hydra in the working directory.

Different features has different ways to disable them:

1. To prevent the creation of a working directory, you can override hydra.run.dir to ..
2. To prevent saving the files into .hydra, override hydra.output_subdir to null.
3. To prevent the creation of logging files, you can disable logging output of hydra/hydra_logging and hydra/job_logging, see this.

A complete example might look like:

$ python foo.py hydra.run.dir=. hydra.output_subdir=null hydra/job_logging=disabled hydra/hydra_logging=disabled

Note that as always you can also override those config values through your config file.

Answer 2

The answer from Omry Yadan works well if you want to solve this using the CLI. However, you can also add these flags to your config file such that you don't have to type them every time you run your script. If you want to go this route, make sure you add the following items in your root config file:

defaults:  
  - _self_  
  - override hydra/hydra_logging: disabled  
  - override hydra/job_logging: disabled  
  
hydra:  
  output_subdir: null  
  run:  
    dir: .