Feathr 0.9 发布，领英开源的企业级高性能特征存储-v2tn

Feathr 是领英为简化机器学习 (ML) 功能管理和提高开发者生产力而构建的特征存储，并已在生产环境中使用多年，该项目于今年 4 月正式开源。

重要变化：

将派生功能的执行引擎改为 Spark SQL，所以对于没有运行最新样本 notebooks 的用户来说，这可能会带来一点破坏性的变化。具体而言，他们可能会面临下方的问题：

Preprocessed DataFrames are: 
{'feature_user_age,feature_user_gift_card_balance,feature_user_has_valid_credit_card,feature_user_tax_rate': JavaObject id=o243}
Traceback (most recent call last):
  File "feathr_pyspark_driver.py", line 107, in <module>
    submit_spark_job(feature_names_funcs)
  File "feathr_pyspark_driver.py", line 85, in submit_spark_job
    py4j_feature_job.mainWithPreprocessedDataFrame(job_param_java_array, new_preprocessed_df_map)
  File "/home/trusted-service-user/cluster-env/env/lib/python3.8/site-packages/py4j/java_gateway.py", line 1304, in __call__
    return_value = get_return_value(
  File "/opt/spark/python/lib/pyspark.zip/pyspark/sql/utils.py", line 117, in deco
pyspark.sql.utils.AnalysisException: Undefined function: 'toBoolean'. This function is neither a registered temporary function nor a permanent function registered in the database 'default'.; line 1 pos 84
)

用户应该修改下方的代码：

feature_user_purchasing_power = DerivedFeature(name="feature_user_purchasing_power",
                                      key=user_id,
                                      feature_type=FLOAT,
                                      input_features=[
                                          feature_user_gift_card_balance, feature_user_has_valid_credit_card],
                                      transform="feature_user_gift_card_balance + if_else(toBoolean(feature_user_has_valid_credit_card), 100, 0)")

为这个：

feature_user_purchasing_power = DerivedFeature(name="feature_user_purchasing_power",
                                      key=user_id,
                                      feature_type=FLOAT,
                                      input_features=[
                                          feature_user_gift_card_balance, feature_user_has_valid_credit_card],
                                      transform="feature_user_gift_card_balance + if(boolean(feature_user_has_valid_credit_card), 100, 0)")