opentelemetry-hook-sampler

Custom function based sampler for opentelemetry-python.

How to install

$ pip install opentelemetry-hook-sampler

How to use

import opentelemetry.trace
from opentelemetry.sdk.resources import SERVICE_NAME
from opentelemetry.sdk.trace import TracerProvider
from opentelemetry_hook_sampler import HookSampler


def sampler_hook():
    """
    Sample 1 in 10 traces.
    
    The example is static, but you can get info from any context available
    in your application. E.g. http request, celery task, thread locals, etc.
    """
    return 10


resource = Resource(attributes={SERVICE_NAME: "foo"})
sampler = HookSampler(sampler_hook)
provider = TracerProvider(resource=resource, sampler=sampler)
opentelemetry.trace.set_tracer_provider(provider)

Honeycomb specific

Honeycomb expects a SampleRate attribute to normalize data. It is not OpenTelemetry spec, but it is supported through opentelemetry_hook_sampler.HoneycombHookSampler.

Sampler examples

django-threadlocals

Be careful, threadlocals module don't work with async Django.

from threadlocals.threadlocals import get_current_request


def sampler_hook():
    request = get_current_request()
    # 10% /foo requests
    if request.path == '/foo':
        return 10
    return 1

django-g

from django_g import get_current_request


def sampler_hook():
    request = get_current_request()
    # 10% /foo requests
    if request.path == '/foo':
        return 10
    return 1

celery

import celery


def sampler_hook():
    task_name = celery.current_app.current_worker_task.request.task
    # 10% foo.bar.baz tasks
    if task_name == 'foo.bar.baz':
        return 10
    return 1