Why did I get "killed" when running 1min of alpha360?

[DanielKui]

###################################
# train model
###################################
data_handler_config = {
    "start_time":"2020-09-14",
    "end_time":"2021-06-20",
    "fit_start_time":"2020-09-20",
    "fit_end_time":"2021-05-20",
    "freq":'1min',
    "instruments": market,
}

task = {
    "model": {
        "class": "LGBModel",
        "module_path": "qlib.contrib.model.gbdt",
        "kwargs": {
            "loss": "mse",
            "colsample_bytree": 0.8879,
            "learning_rate": 0.0421,
            "subsample": 0.8789,
            "lambda_l1": 205.6999,
            "lambda_l2": 580.9768,
            "max_depth": 8,
            "num_leaves": 210,
            "num_threads": 20,
        },
    },
    "dataset": {
        "class": "DatasetH",
        "module_path": "qlib.data.dataset",
        "kwargs": {
            "handler": {
                "class": "Alpha360",
                "module_path": "qlib.contrib.data.handler",
                "kwargs": data_handler_config,
            },
            "segments": {
    "train": ("2020-09-14", "2020-10-15"),
    "valid": ("2020-10-16", "2020-12-20"),
    "test": ("2020-12-14", "2021-05-20"),
            },
        },
    },
}


h = Alpha360(**data_handler_config)
alpha360_df_feature = h.fetch(col_set="feature")
alpha360_df_feature = alpha360_df_feature.loc[:,~(alpha360_df_feature == 0.0).all()]
alpha360_df_feature = alpha360_df_feature.loc[~(alpha360_df_feature.eq(0.0).all(1))]

print(alpha360_df_feature)

# model initiaiton
model = init_instance_by_config(task["model"])
dataset = init_instance_by_config(task["dataset"])

# start exp to train model
with R.start(experiment_name="train_model"):
    R.log_params(**flatten_dict(task))
    model.fit(dataset)
    R.save_objects(trained_model=model)
    rid = R.get_recorder().id

when I try tu run jupyter notebook, it always showed that python kernel has been restarted.

What's datetime range does it support? I tried one day range, it works fine from 2020-09-14 to 2020-09-15,
Most of feature in alpha360 are zero. this range may a little bit short.

My machine:
Debian 11
RAM 64G
4 processors