Description

OpenCensus - A stats collection and distributed tracing framework ================================================================= |gitter| |travisci| |circleci| |pypi| |compat_check_pypi| |compat_check_github| .. |travisci| image:: https://travis-ci.org/census-instrumentation/opencensus-python.svg?branch=master :target: https://travis-ci.org/census-instrumentation/opencensus-python .. |circleci| image:: https://circleci.com/gh/census-instrumentation/opencensus-python.svg?style=shield :target: https://circleci.com/gh/census-instrumentation/opencensus-python .. |gitter| image:: https://badges.gitter.im/census-instrumentation/lobby.svg :target: https://gitter.im/census-instrumentation/lobby?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge .. |pypi| image:: https://badge.fury.io/py/opencensus.svg :target: https://pypi.org/project/opencensus/ .. |compat_check_pypi| image:: https://python-compatibility-tools.appspot.com/one_badge_image?package=opencensus :target: https://python-compatibility-tools.appspot.com/one_badge_target?package=opencensus .. |compat_check_github| image:: https://python-compatibility-tools.appspot.com/one_badge_image?package=git%2Bgit%3A//github.com/census-instrumentation/opencensus-python.git :target: https://python-compatibility-tools.appspot.com/one_badge_target?package=git%2Bgit%3A//github.com/census-instrumentation/opencensus-python.git `OpenCensus`_ for Python. OpenCensus provides a framework to measure a server's resource usage and collect performance stats. This repository contains Python related utilities and supporting software needed by OpenCensus. .. _OpenCensus: https://github.com/census-instrumentation - `API Documentation`_ .. _API Documentation: https://opencensus.io/api/python/trace/usage.html -------- Tracing -------- Installation & basic usage -------------------------- 1. Install the opencensus package using `pip`_ or `pipenv`_: :: pip install opencensus pipenv install opencensus 2. Initialize a tracer for your application: .. code:: python from opencensus.trace.tracer import Tracer from opencensus.trace.samplers import AlwaysOnSampler tracer = Tracer(sampler=AlwaysOnSampler()) .. _pip: https://pip.pypa.io .. _pipenv: https://docs.pipenv.org/ 3. Initialize a view_manager and a stats_recorder for your application: .. code:: python from opencensus.stats import stats as stats_module stats = stats_module.stats view_manager = stats.view_manager stats_recorder = stats.stats_recorder Usage ----- You can collect traces using the ``Tracer`` `context manager`_: .. code:: python from opencensus.trace.tracer import Tracer from opencensus.trace.samplers import AlwaysOnSampler # Initialize a tracer, by default using the `PrintExporter` tracer = Tracer(sampler=AlwaysOnSampler()) # Example for creating nested spans with tracer.span(name='span1'): do_something_to_trace() with tracer.span(name='span1_child1'): do_something_to_trace() with tracer.span(name='span1_child2'): do_something_to_trace() with tracer.span(name='span2'): do_something_to_trace() OpenCensus will collect everything within the ``with`` statement as a single span. Alternatively, you can explicitly start and end a span: .. code:: python from opencensus.trace.tracer import Tracer from opencensus.trace.samplers import AlwaysOnSampler # Initialize a tracer, by default using the `PrintExporter` tracer = Tracer(sampler=AlwaysOnSampler()) tracer.start_span(name='span1') do_something_to_trace() tracer.end_span() .. _context manager: https://docs.python.org/3/reference/datamodel.html#context-managers Customization ------------- There are several things you can customize in OpenCensus: * **Excludelist**, which excludes certain hosts and paths from being tracked. By default, the health check path for the App Engine flexible environment is not tracked, you can turn it on by excluding it from the excludelist setting. * **Exporter**, which sends the traces. By default, the traces are printed to stdout in JSON format. You can choose different exporters to send the traces to. There are three built-in exporters, which are ``PrintExporter``, ``FileExporter`` and ``LoggingExporter``, the other exporters are provided as `extensions <#trace-exporter>`__. * **Sampler**, which determines how traces are sampled. The default sampler is the ``ProbabilitySampler``, which samples (i.e. enables tracing for) a percentage of all requests. Sampling is deterministic according to the trace ID. To force sampling for all requests, or to prevent any request from being sampled, see ``AlwaysOnSampler`` and ``AlwaysOffSampler``. * **Propagator**, which serializes and deserializes the ``SpanContext`` and its headers. The default propagator is ``Tr