Ability to create separate trace in Lambda

[mlnrt]

Hello, in the context of using ADOT for a Lambda function, is it possible to create a separate trace from the Lambda trace?

I am running LangChain in a Lambda function and LangChain has many many components to perform all the actions the AI agent needs to do to answer the user question and I want to trace the details. I don't want to just trace the services but all the LangChain inner steps.
Using the X-Ray tracer, I patch myself all the LangChain Runnables to start a subsegment on their invoke() method and I have a result as follow.

That is all good but I also want the graphical "service map" view of that. This is not possible with the default X-Ray SDK since you can't create new segments inside Lambda. So I was wondering if using the ADOT framework, I could create a completely separate "LangChain" trace (essentially having the service trace and LangChain trace separate, treating LangChain as a separate application)?

I tried to create a separate "adot tracer" with a new context and add new spans for all LangChain Runnables but it doesn't work.

Is there a way to do this in Lambda?

[bjrara]

I tried to create a separate "adot tracer" with a new context and add new spans for all LangChain Runnables but it doesn't work.

How did you start a root span using ADOT? Can you provide a code snippet?

[mlnrt]

Hello @bjrara thank you for replying. I tried different approaches/code.
At the simplest I tried the following, creating a new OTEL span, specifying the context as None to create what should be a new trace root. I tried with and without setting the trace kind.

from opentelemetry import trace
from opentelemetry.trace import SpanKind, Status, StatusCode

tracer = trace.get_tracer("my_custom_langchain_tracer")

def lambda_handler(event, context):
    ...
    with tracer.start_as_current_span(
        "LangChain", 
        kind=SpanKind.SERVER,
        context=None 
    ) as span:
        ...

I also tried to specify the trace exporter and provider myself doing something like

from opentelemetry import trace
from opentelemetry.trace import SpanContext, NonRecordingSpan
from opentelemetry.sdk.trace import TracerProvider
from opentelemetry.sdk.trace.export import BatchSpanProcessor
from opentelemetry.exporter.otlp.proto.http.trace_exporter import OTLPSpanExporter

tracer_provider = TracerProvider()
otlp_exporter = OTLPSpanExporter(endpoint="http://localhost:4317")
tracer_provider.add_span_processor(BatchSpanProcessor(otlp_exporter))
trace.set_tracer_provider(tracer_provider)