How to save and load my Ax Client and experiment about ax

[lena-kashtelyan]

Hey, @KamjiLee, it seems that you are looking to save the optimization to .json file, not to an SQL database, so the functions you need are:

ax_client = AxClient()

# Save `AxClient` to a JSON snapshot.
ax_client.save(filepath='my_json.json')

# Reinstantiate an `AxClient` from a JSON snapshot.
ax_client = AxClient.load(filepath='my_json.json')

You can also not pass a filepath argument to save and load, in which case it will use the default. Here are the API references for save and load.

ax_client.load_experiment(experiment_name='my_experiment') (API ref) is used to reload an experiment saved to an SQL database. If that is what you are trying to do, you will need to pass DB settings to AxClient on instantiation and reload the experiment by its name (no need to separately save it, it will be saved each time a change is made).

You will need the latest stable version for the saving functionality, so do make sure to update your Ax installation to 0.1.5.

Feel free to reopen the issue if that doesn't work or if you have a follow-up!

[sgbaird]

# Reinstantiate an `AxClient` from a JSON snapshot.
ax_client = AxClient.load(filepath='my_json.json')

I believe this syntax was updated:

Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "[c:\users\sterg\documents\github\sparks-baird\ax\ax\service\ax_client.py]()", line 1739, in load
    raise NotImplementedError(
NotImplementedError: Use `load_experiment_from_database` to load from SQL database or `load_from_json_file` to load optimization state from .json file.

So:

# Reinstantiate an `AxClient` from a JSON snapshot.
ax_client = AxClient.load_from_json_file(filepath='my_json.json')

Same with save:

NotImplementedError                       Traceback (most recent call last)
[<ipython-input-247-0bd18695ff53>](https://localhost:8080/#) in <module>
----> 2 ax_client.save(filepath='my_json.json')

[/usr/local/lib/python3.7/dist-packages/ax/service/ax_client.py](https://localhost:8080/#) in save(filepath)
   1780     def save(filepath: Optional[str] = None) -> None:
   1781         raise NotImplementedError(
-> 1782             "Use `save_to_json_file` to save optimization state to .json file."
   1783         )

NotImplementedError: Use `save_to_json_file` to save optimization state to .json file.

ax_client.save_to_json_file(filepath='my_json.json')