OpenCensus Shim

This example shows how to use the :doc:opentelemetry-opencensus-shim package <../../shim/opencensus_shim/opencensus_shim> to interact with libraries instrumented with opencensus-python <https://github.com/census-instrumentation/opencensus-python>_.

The source files required to run this example are available :scm_web:here <docs/examples/opencensus-shim/>.

Installation

Jaeger

Start Jaeger

.. code-block:: sh

docker run --rm \
    -p 4317:4317 \
    -p 4318:4318 \
    -p 16686:16686 \
    jaegertracing/all-in-one:latest \
    --log-level=debug

Python Dependencies

Install the Python dependencies in :scm_raw_web:requirements.txt <docs/examples/opencensus-shim/requirements.txt >

.. code-block:: sh

pip install -r requirements.txt

Alternatively, you can install the Python dependencies separately:

.. code-block:: sh

pip install \
    opentelemetry-api \
    opentelemetry-sdk \
    opentelemetry-exporter-otlp \
    opentelemetry-opencensus-shim \
    opentelemetry-instrumentation-sqlite3 \
    opencensus \
    opencensus-ext-flask \
    Flask

Run the Application

Start the application in a terminal.

.. code-block:: sh

flask --app app run -h 0.0.0.0

Point your browser to the address printed out (probably http://127.0.0.1:5000). Alternatively, just use curl to trigger a request:

.. code-block:: sh

curl http://127.0.0.1:5000

Jaeger UI

Open the Jaeger UI in your browser at <http://localhost:16686>_ and view traces for the "opencensus-shim-example-flask" service. Click on a span named "span" in the scatter plot. You will see a span tree with the following structure:

• span
  • query movies from db
    • SELECT
  • build response html

The root span comes from OpenCensus Flask instrumentation. The children query movies from db and build response html come from the manual instrumentation using OpenTelemetry's :meth:opentelemetry.trace.Tracer.start_as_current_span. Finally, the SELECT span is created by OpenTelemetry's SQLite3 instrumentation. Everything is exported to Jaeger using the OpenTelemetry exporter.

Useful links

• OpenTelemetry_
• :doc:../../shim/opencensus_shim/opencensus_shim

.. _OpenTelemetry: https://github.com/open-telemetry/opentelemetry-python/