tracing.md

Tracing

Python-Pilosa supports distributed tracing via the OpenTracing API.

In order to use a tracer with Python-Pilosa, you should:

1. Create the tracer,
2. Pass the tracer=tracer_object to Client().

In this document, we will be using the Jaeger tracer, but OpenTracing has support for other tracing systems.

Running the Pilosa Server

Let's run a temporary Pilosa container:

$ docker run -it --rm -p 10101:10101 pilosa/pilosa:v1.2.0

Check that you can access Pilosa:

$ curl localhost:10101
Welcome. Pilosa is running. Visit https://www.pilosa.com/docs/ for more information.

Running the Jaeger Server

Let's run a Jaeger Server container:

$ docker run -it --rm -p 6831:6831/udp -p 5775:5775/udp -p 16686:16686 jaegertracing/all-in-one:latest
...<title>Jaeger UI</title>...

Writing the Sample Code

The sample code depdends on the Jaeger Python client, so let's install it first:

$ pip install jaeger-client

Save the following sample code as pypilosa-tracing.py:

from pilosa import Client
from jaeger_client import Config


def get_tracer(service_name):
    config = Config(
        config={
            'sampler': {
                'type': 'const',
                'param': 1,
            },
            'local_agent': {
                'reporting_host': '127.0.0.1'
            }
        },
        service_name=service_name
    )
    return config.new_tracer()


def main():
    # Create the tracer.
    tracer = get_tracer("python_client_test")
    
    # Create the client, and pass the tracer.
    client = Client(":10101", tracer=tracer)

    # Read the schema from the server.
    # This should create a trace on the Jaeger server.
    schema = client.schema()

    # Create and sync the sample schema.
    # This should create a trace on the Jaeger server.
    my_index = schema.index("my-index")
    my_field = my_index.field("my-field")
    client.sync_schema(schema)
    
    # Run a query on Pilosa.
    # This should create a trace on the Jaeger server.
    client.query(my_field.set(1, 1000))

    tracer.close()


if __name__ == "__main__":
    main()

Checking the Tracing Data

Run the sample code:

$ python pypilosa-tracing.py

• Open http://localhost:16686 in your web browser to visit Jaeger UI.
• Click on the Search tab and select python_pilosa_test in the Service dropdown on the right.
• Click on Find Traces button at the bottom left.
• You should see a couple of traces, such as: Client.Query, Client.CreateField, Client.Schema, etc.