🐛 Bug Report: Spans being detached from Langchain parent traces

Which component is this bug for?

Langchain Instrumentation

📜 Description

Calls to functions instrumented by other libraries get detached from the parent trace. This happens for example in Langchain chains which call a retriever which is instrumented by opentelemetry.instrumentation.sqlalchemy. The nominally child spans are created but are independent of each other and of the actual parent.

Occurs for both sync and async calls.

👟 Reproduction steps

This code reproduces the issue given a local postgres server:

import os

from langchain_core.prompts import PromptTemplate
from langchain_core.output_parsers import StrOutputParser
from langchain_core.runnables import RunnablePassthrough
from langchain_openai import ChatOpenAI, OpenAIEmbeddings
from langchain_postgres import PGVector
from opentelemetry.sdk.trace.export import ConsoleSpanExporter
from traceloop.sdk import Traceloop


Traceloop.init(
    exporter=ConsoleSpanExporter(),
)

PROMPT_TEMPLATE = """
You are an assistant for question-answering tasks. Use the following pieces of retrieved context to answer the question.

Question: {question} 

Context: {context} 

Answer:
"""

qa_prompt = PromptTemplate.from_template(PROMPT_TEMPLATE)

llm = AzureChatOpenAI()

embeddings = OpenAIEmbeddings()

vectorstore = PGVector(
    connection=PGVector.connection_string_from_db_params(
        driver="psycopg",
        host="localhost",
        port=5432,
        database="vectors",
        user="postgres",
        password="localpassword"
    ),
    embeddings=embeddings,
)

def format_docs(docs):
    return "\n\n".join(doc.page_content for doc in docs)

qa_chain = (
    {
        "context": vectorstore.as_retriever() | format_docs,
        "question": RunnablePassthrough(),
    }
    | qa_prompt | llm | StrOutputParser()
)

qa_chain.invoke("What are autonomous agents?")

👍 Expected behavior

All spans in the chain should have the same trace_id and appropriate parent_id.

👎 Actual Behavior with Screenshots

Example:

{
    "name": "RunnableAssign<filter>.langchain.task",
    "context": {
        "trace_id": "**0x2b1a7979f5725daf1a624b67a66c0d65**",
        "span_id": "0xff0ed485230f3387",
        "trace_state": "[]"
    },
    "kind": "SpanKind.INTERNAL",
    "parent_id": "**0x8e9d707a6ced4a3e**",
    "start_time": "2024-07-11T16:54:46.031626Z",
    "end_time": "2024-07-11T16:54:46.146668Z",
    "status": {
        "status_code": "UNSET"
    },
    "attributes": {
        "traceloop.span.kind": "task",
        "traceloop.entity.name": "RunnableAssign<filter>.langchain.task"
    },
    "events": [],
    "links": [],
    "resource": {
        "attributes": {
            "service.name": "dev"
        },
        "schema_url": ""
    }
}
{
    "name": "connect",
    "context": {
        "trace_id": "**0x8e897f889032d34c89fab768696dda50**",
        "span_id": "0x16564f54d9e75f4a",
        "trace_state": "[]"
    },
    "kind": "SpanKind.CLIENT",
    "parent_id": **null**,
    "start_time": "2024-07-11T16:54:46.158278Z",
    "end_time": "2024-07-11T16:54:46.178849Z",
    "status": {
        "status_code": "UNSET"
    },
    "attributes": {
        "net.peer.name": "localhost",
        "net.peer.port": 5432,
        "db.name": "postgres",
        "db.user": "postgres",
        "db.system": "postgresql"
    },
    "events": [],
    "links": [],
    "resource": {
        "attributes": {
            "service.name": "dev"
        },
        "schema_url": ""
    }
}
{
    "name": "connect",
    "context": {
        "trace_id": "**0x81bd9194f61397cbe0bd534c37f0ea35**",
        "span_id": "0x5b67b8e9ffad9bf1",
        "trace_state": "[]"
    },
    "kind": "SpanKind.CLIENT",
    "parent_id": **null**,
    "start_time": "2024-07-11T16:54:46.182237Z",
    "end_time": "2024-07-11T16:54:46.182272Z",
    "status": {
        "status_code": "UNSET"
    },
    "attributes": {
        "net.peer.name": "localhost",
        "net.peer.port": 5432,
        "db.name": "postgres",
        "db.user": "postgres",
        "db.system": "postgresql"
    },
    "events": [],
    "links": [],
    "resource": {
        "attributes": {
            "service.name": "dev"
        },
        "schema_url": ""
    }
}
{
    "name": "connect",
    "context": {
        "trace_id": "**0xee2ee041c775319c24a37d968f4afbf2**",
        "span_id": "0xdbc3250f693b6ec2",
        "trace_state": "[]"
    },
    "kind": "SpanKind.CLIENT",
    "parent_id": **null**,
    "start_time": "2024-07-11T16:54:46.189804Z",
    "end_time": "2024-07-11T16:54:46.189848Z",
    "status": {
        "status_code": "UNSET"
    },
    "attributes": {
        "net.peer.name": "localhost",
        "net.peer.port": 5432,
        "db.name": "postgres",
        "db.user": "postgres",
        "db.system": "postgresql"
    },
    "events": [],
    "links": [],
    "resource": {
        "attributes": {
            "service.name": "dev"
        },
        "schema_url": ""
    }
}
{
    "name": "connect",
    "context": {
        "trace_id": "**0x175f1f1a4b4a24a093615e2d6dc9be0c**",
        "span_id": "0xc96e709b49c7a085",
        "trace_state": "[]"
    },
    "kind": "SpanKind.CLIENT",
    "parent_id": **null**,
    "start_time": "2024-07-11T16:54:47.339822Z",
    "end_time": "2024-07-11T16:54:47.340088Z",
    "status": {
        "status_code": "UNSET"
    },
    "attributes": {
        "net.peer.name": "localhost",
        "net.peer.port": 5432,
        "db.name": "postgres",
        "db.user": "postgres",
        "db.system": "postgresql"
    },
    "events": [],
    "links": [],
    "resource": {
        "attributes": {
            "service.name": "dev"
        },
        "schema_url": ""
    }
}
{
    "name": "RunnableSequence.langchain.task",
    "context": {
        "trace_id": "**0x2b1a7979f5725daf1a624b67a66c0d65**",
        "span_id": "0x8e9d707a6ced4a3e",
        "trace_state": "[]"
    },
    "kind": "SpanKind.INTERNAL",
    "parent_id": "**0x73b5335f38792980**",
    "start_time": "2024-07-11T16:54:46.027813Z",
    "end_time": "2024-07-11T16:54:47.468602Z",
    "status": {
        "status_code": "UNSET"
    },
    "attributes": {
        "traceloop.span.kind": "task",
        "traceloop.entity.name": "RunnableSequence.langchain.task"
    },
    "events": [],
    "links": [],
    "resource": {
        "attributes": {
            "service.name": "dev"
        },
        "schema_url": ""
    }
}

🤖 Python Version

No response

📃 Provide any additional context for the Bug.

Present in 0.25.3.

👀 Have you spent some time to check if this bug has been raised before?

• I checked and didn't find similar issue

Are you willing to submit PR?

None

Start by running the provided Langchain reproduction with a local PostgreSQL server and inspect the Langchain instrumentation alongside sqlalchemy instrumentation. Check both synchronous and asynchronous calls, then verify that all spans share one trace_id and that database spans have the appropriate parent_id under the Langchain trace.