patrick2•9mo ago

LCEL Batch

Hi 🙂 I'm facing some weird behavior when using a LCEL chain with batch() instead of invoke ... is that something anyone or the team occured already? Basically I'm running the chain on multiple inputs for an eval run.

langfuse_handler = CallbackHandler(public_key=LANGFUSE_CONF["PUBLIC_KEY"], secret_key=LANGFUSE_CONF["SECRET_KEY"], host=LANGFUSE_CONF["HOST"])
...
chain.batch(eval_questions, config={"callbacks": [langfuse_handler]})

langfuse_handler = CallbackHandler(public_key=LANGFUSE_CONF["PUBLIC_KEY"], secret_key=LANGFUSE_CONF["SECRET_KEY"], host=LANGFUSE_CONF["HOST"])
...
chain.batch(eval_questions, config={"callbacks": [langfuse_handler]})



It yields into multiple errors in

on_chain_start and on_chain_end`: eg

File "/Users/.../langfuse/callback.py", line 239, in on_chain_start
    self.runs[run_id] = self.runs[parent_run_id].span(
KeyError: UUID('8d96860b-caf8-4d04-852f-9f3525f945f9')
2024-01-11 17:40:33,740:ERROR - run not found

File "/Users/.../langfuse/callback.py", line 239, in on_chain_start
    self.runs[run_id] = self.runs[parent_run_id].span(
KeyError: UUID('8d96860b-caf8-4d04-852f-9f3525f945f9')
2024-01-11 17:40:33,740:ERROR - run not found

  File "/Users/.../langfuse/callback.py", line 396, in on_chain_end
    raise Exception("run not found")
Exception: run not found

  File "/Users/.../langfuse/callback.py", line 396, in on_chain_end
    raise Exception("run not found")
Exception: run not found

UI shows 1 run recorded run, others seem to be empty. Is batch behavior so far not supported, or any clues 🙂 ? Thanks to the team!

5 Replies

Max•9mo ago

Hi @patrick2, we do not support LCEL yet. Something that is on our list to improve.

FAST Jo•9mo ago

Well LCEL with the invoke method works though... 😀 chain.invoke(question, config={"callbacks": [langfuse_handler]})

Max•9mo ago

Thanks @FAST Jo !

patrick2•9mo ago

thx - yeah that's workaround even though its only sequential then 🙂 btw is it possible to add tags / names to when using the langchain integration in invoke?

Max•8mo ago

Hi, currenlty this is not possible, but looking into these.