Opencensus Stackdriver traces from Python app not appearing in the Trace list in GCP

I'm comparing different tracing backend using OpenCensus. I already have the simple OpenCensus.io python samples running fine using Zipkin and Azure Monitor.

Now I'm trying to test using GCP's Stackdriver...

I have set up the test code from Opencensus https://opencensus.io/exporters/supported-exporters/python/stackdriver/ as follows:

#!/usr/bin/env python

import os

from opencensus.common.transports.async_ import AsyncTransport
from opencensus.ext.stackdriver.trace_exporter import StackdriverExporter
from opencensus.trace.tracer import Tracer

def main():
    sde = StackdriverExporter(
        project_id=os.environ.get("GCP_PROJECT_ID"),
        transport=AsyncTransport)

    tracer = Tracer(exporter=sde)
    with tracer.span(name="doingWork") as span:
        for i in range(10):
            pass

if __name__ == "__main__":
    main()

I have set the environment variable for GCP_PROJECT_ID and also have my key file path for my service account JSON file set in GOOGLE_APPLICATION_CREDENTIALS.

The service account has the "Cloud trace agent" role.

My code runs through with no errors but I can't see any info appearing in the GCP console under traces or in the monitoring dashboard.

Am I missing something?

Environment notes: I'm testing this from my local Windows machine using Python 3.7.2

One thing which is not very clear in the doc is that by default, traces are sampled (see source file here), so every call is properly logged, but only 1e-4 trace is stored. It helps to reduce costs but it is a major pain point during debug.

If you want to log all traces, you can use AlwaysOnSampler and pass it to the tracer :

import os

from opencensus.common.transports.async_ import AsyncTransport
from opencensus.ext.stackdriver.trace_exporter import StackdriverExporter
from opencensus.trace.tracer import Tracer
from opencensus.trace.samplers import AlwaysOnSampler

def main():
    sde = StackdriverExporter(
        project_id=os.environ.get("GCP_PROJECT_ID"),
        transport=AsyncTransport)

    tracer = Tracer(exporter=sde, sampler=AlwaysOnSampler())
    with tracer.span(name="doingWork") as span:
        for i in range(10):
            pass

if __name__ == "__main__":
    main()

Hope it fixes your issue !