Bug Description

我正在尝试使用Langchain框架构建一个启用RAG的AI应用程序，但在运行时遇到了错误。错误信息如下：

Traceback (most recent call last):
 File "C:\Users\Selvabharath\AppData\Local\Programs\Python\Python311\Lib\site-packages\langchain_aws\llms\bedrock.py", line 690, in _prepare_input_and_invoke
 response = self.client.invoke_model(**request_options)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 File "C:\Users\Selvabharath\AppData\Local\Programs\Python\Python311\Lib\site-packages\botocore\client.py", line 565, in _api_call
 return self._make_api_call(operation_name, kwargs)
         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 botocore.errorfactory.ValidationException: An error occurred (ValidationException) when calling the InvokeModel operation: Validation Error
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
 File "c:\Users\Selvabharath\Documents\Selva\9_Work\Python_Projects\Demo_Sean\rag_backend._without_frontpy.py", line 45, in response_content
 response_content = rag_response(rag_index()), question="what is Underlying earnings per share")
             ^\~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
File "c:\Users\Selvabharath\AppData\Local\Programs\Python\Python311\Lib\site-packages\langchain\indexes\vectorstore.py", line 50, in query
 return chain.invoke({chain.input_key: question})[chain.output_key]
         ^\~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
File "c:\Users\Selvabharath\AppData\Local\Programs\Python\Python311\Lib\site-packages\langchain/chains/base.py", line 166, in invoke
 raise e
         ^\~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
File "c:\Users\Selvabharath\AppData\Local\Programs\Python\Python311\Lib\site-packages\langchain/chains/retrieval_qa\base.py", line 146, in _call
 answer = self.combine_documents_chain.run(
         ^\~~~~~~~~~~~~~~~~~~~~~~~~~
File "c:\Users\Selvabharath\AppData\Local\Programs\Python\Python311\Lib\site-packages\langchain_core_api\deprecation.py", line 168, in warning_emitting_wrapper
 return wrapped(*args, **kwargs)
         ^\~~~~~~~~~~~~~
File "c:\Users\Selvabharath\AppData\Local\Programs\Python\Python311\Lib\site-packages\langchain/chains/base.py", line 605, in run
 return self(kwargs, callbacks=callbacks, tags=tags, metadata=metadata)[
         ^\~~~~~~~~~
File "c:\Users\Selvabharath\AppData\Local\Programs\Python\Python311\Lib\site-packages\langchain/chains/base.py", line 383, in **call
 return self.invoke(
         ^\~~~~~~~~~
File "c:\Users\Selvabharath\AppData\Local\Programs
根据提供的错误信息，问题出在调用 Bedrock 服务时发生了验证异常。具体来说，是在调用 InvokeModel 操作时出现了验证错误。为了解决这个问题，你可以尝试以下方法：

1. 确保你的 AWS 凭证配置正确。检查 `credentials_profile_name` 是否设置为正确的 AWS 配置文件名称。
2. 确保你使用的 LLM 模型 ID 是正确的。在这个例子中，使用的是 `mistral.mistral-7b-instruct-v0:2`,请确保这个模型 ID 在你的 AWS 账户中可用。
3. 检查输入的 PDF 文件路径是否正确。在这个例子中，文件路径是 `C:/Users/Selvabharath/Documents/Selva/9_Work/AI_with_RAG/Data Source/sample_input.pdf`,请确保这个路径下确实存在该文件。
4. 如果以上方法都无法解决问题，你可以尝试更新 langchain 和 langchain_aws 库到最新版本，或者查看官方文档和 GitHub 仓库中的已知问题和解决方案。