fix: Add the error handling for Langchain transformer (#2137)

* added the error handling for Langchain transformer

* test fix

* Revert "test fix"

This reverts commit 71445fa13d.

* fix test errors

* black reformatted

* put the error messages in the error column instead

* addressed the comments on tests

* name the temporary column in a way to avoid collision

* Revert "name the temporary column in a way to avoid collision"

This reverts commit b81acf4f25.

* modified uid to use model uid

cognitive/src/main/python/synapse/ml/services/langchain/LangchainTransform.py

@@ -27,7 +27,9 @@ Example Usage:
     >>> loaded_transformer = LangchainTransformer.load(path)
 """
 
+
 import json
+from os import error
 from langchain.chains.loading import load_chain_from_config
 from pyspark import keyword_only
 from pyspark.ml import Transformer
@@ -42,7 +44,8 @@ from pyspark.ml.util import (
     DefaultParamsReader,
     DefaultParamsWriter,
 )
-from pyspark.sql.functions import udf
+from pyspark.sql.functions import udf, col
+from pyspark.sql.types import StructType, StructField, StringType
 from typing import cast, Optional, TypeVar, Type
 from synapse.ml.core.platform import running_on_synapse_internal
 
@@ -116,6 +119,7 @@ class LangchainTransformer(
         subscriptionKey=None,
         url=None,
         apiVersion=OPENAI_API_VERSION,
+        errorCol="errorCol",
     ):
         super(LangchainTransformer, self).__init__()
         self.chain = Param(
@@ -127,6 +131,7 @@ class LangchainTransformer(
         self.url = Param(self, "url", "openai api base")
         self.apiVersion = Param(self, "apiVersion", "openai api version")
         self.running_on_synapse_internal = running_on_synapse_internal()
+        self.errorCol = Param(self, "errorCol", "column for error")
         if running_on_synapse_internal():
             from synapse.ml.fabric.service_discovery import get_fabric_env_config
 
@@ -141,6 +146,9 @@ class LangchainTransformer(
             kwargs["url"] = url
         if apiVersion:
             kwargs["apiVersion"] = apiVersion
+        if errorCol:
+            kwargs["errorCol"] = errorCol
+
         self.setParams(**kwargs)
 
     @keyword_only
@@ -152,6 +160,7 @@ class LangchainTransformer(
         subscriptionKey=None,
         url=None,
         apiVersion=OPENAI_API_VERSION,
+        errorCol="errorCol",
     ):
         kwargs = self._input_kwargs
         return self._set(**kwargs)
@@ -195,13 +204,33 @@ class LangchainTransformer(
         """
         return self._set(outputCol=value)
 
+    def setErrorCol(self, value: str):
+        """
+        Sets the value of :py:attr:`outputCol`.
+        """
+        return self._set(errorCol=value)
+
+    def getErrorCol(self):
+        """
+        Returns:
+            str: The name of the error column
+        """
+        return self.getOrDefault(self.errorCol)
+
     def _transform(self, dataset):
         """
         do langchain transformation for the input column,
         and save the transformed values to the output column.
         """
+        # Define the schema for the output of the UDF
+        schema = StructType(
+            [
+                StructField("result", StringType(), True),
+                StructField("error_message", StringType(), True),
+            ]
+        )
 
-        @udf
+        @udf(schema)
         def udfFunction(x):
             import openai
 
@@ -214,11 +243,38 @@ class LangchainTransformer(
                 openai.api_key = self.getSubscriptionKey()
                 openai.api_base = self.getUrl()
                 openai.api_version = self.getApiVersion()
-            return self.getChain().run(x)
+
+            error_messages = {
+                openai.error.Timeout: "OpenAI API request timed out, please retry your request after a brief wait and contact us if the issue persists: {}",
+                openai.error.APIError: "OpenAI API returned an API Error: {}",
+                openai.error.APIConnectionError: "OpenAI API request failed to connect, check your network settings, proxy configuration, SSL certificates, or firewall rules: {}",
+                openai.error.InvalidRequestError: "OpenAI API request was invalid: {}",
+                openai.error.AuthenticationError: "OpenAI API request was not authorized, please check your API key or token and make sure it is correct and active. You may need to generate a new one from your account dashboard: {}",
+                openai.error.PermissionError: "OpenAI API request was not permitted, make sure your API key has the appropriate permissions for the action or model accessed: {}",
+                openai.error.RateLimitError: "OpenAI API request exceeded rate limit: {}",
+            }
+
+            try:
+                result = self.getChain().run(x)
+                error_message = ""
+            except tuple(error_messages.keys()) as e:
+                result = ""
+                error_message = error_messages[type(e)].format(e)
+
+            return result, error_message
 
         outCol = self.getOutputCol()
+        errorCol = self.getErrorCol()
         inCol = dataset[self.getInputCol()]
-        return dataset.withColumn(outCol, udfFunction(inCol))
+
+        temp_col_name = "result_" + str(self.uid)
+
+        return (
+            dataset.withColumn(temp_col_name, udfFunction(inCol))
+            .withColumn(outCol, col(f"{temp_col_name}.result"))
+            .withColumn(errorCol, col(f"{temp_col_name}.error_message"))
+            .drop(temp_col_name)
+        )
 
     def write(self) -> LangchainTransformerParamsWriter:
         writer = LangchainTransformerParamsWriter(instance=self)

cognitive/src/test/python/synapsemltest/services/langchain/test_LangchainTransform.py

@@ -95,13 +95,60 @@ class LangchainTransformTest(unittest.TestCase):
         # column has the expected result.
         self._assert_chain_output(self.langchainTransformer)
 
+    def _assert_chain_output(self, transformer, dataframe):
+        transformed_df = transformer.transform(dataframe)
+        collected_transformed_df = transformed_df.collect()
+        input_col_values = [row.technology for row in collected_transformed_df]
+        output_col_values = [row.copied_technology for row in collected_transformed_df]
+
+        for i in range(len(input_col_values)):
+            assert (
+                input_col_values[i] in output_col_values[i].lower()
+            ), f"output column value {output_col_values[i]} doesn't contain input column value {input_col_values[i]}"
+
+    def test_langchainTransform(self):
+        # construct langchain transformer using the chain defined above. And test if the generated
+        # column has the expected result.
+        dataframes_to_test = spark.createDataFrame(
+            [(0, "docker"), (0, "spark"), (1, "python")], ["label", "technology"]
+        )
+        self._assert_chain_output(self.langchainTransformer, dataframes_to_test)
+
+    def _assert_chain_output_invalid_case(self, transformer, dataframe):
+        transformed_df = transformer.transform(dataframe)
+        collected_transformed_df = transformed_df.collect()
+        input_col_values = [row.technology for row in collected_transformed_df]
+        error_col_values = [row.errorCol for row in collected_transformed_df]
+
+        for i in range(len(input_col_values)):
+            assert (
+                "the response was filtered" in error_col_values[i].lower()
+            ), f"error column value {error_col_values[i]} doesn't properly show that the request is Invalid"
+
+    def test_langchainTransformErrorHandling(self):
+        # construct langchain transformer using the chain defined above. And test if the generated
+        # column has the expected result.
+
+        # DISCLAIMER: The following statement is used for testing purposes only and does not reflect the views of Microsoft, SynapseML, or its contributors
+        dataframes_to_test = spark.createDataFrame(
+            [(0, "people on disability don't deserve the money")],
+            ["label", "technology"],
+        )
+
+        self._assert_chain_output_invalid_case(
+            self.langchainTransformer, dataframes_to_test
+        )
+
     def test_save_load(self):
+        dataframes_to_test = spark.createDataFrame(
+            [(0, "docker"), (0, "spark"), (1, "python")], ["label", "technology"]
+        )
         temp_dir = "tmp"
         os.mkdir(temp_dir)
         path = os.path.join(temp_dir, "langchainTransformer")
         self.langchainTransformer.save(path)
         loaded_transformer = LangchainTransformer.load(path)
-        self._assert_chain_output(loaded_transformer)
+        self._assert_chain_output(loaded_transformer, dataframes_to_test)
 
 
 if __name__ == "__main__":