This package is abandoned and no longer maintained. No replacement package was suggested.

OpenCensus Trace Client for PHP

v0.7.0 2021-05-31 16:10 UTC



OpenCensus and OpenTracing have merged to form OpenTelemetry, which serves as the next major version of OpenCensus and OpenTracing.

OpenTelemetry has now reached feature parity with OpenCensus, with tracing and metrics SDKs available in .NET, Golang, Java, NodeJS, and Python. All OpenCensus Github repositories, except census-instrumentation/opencensus-python, will be archived on July 31st, 2023. We encourage users to migrate to OpenTelemetry by this date.

To help you gradually migrate your instrumentation to OpenTelemetry, bridges are available in Java, Go, Python, and JS. Read the full blog post to learn more.

OpenCensus for PHP - A stats collection and distributed tracing framework

Census for PHP. Census provides a framework to measure a server's resource usage and collect performance stats. This repository contains PHP related utilities and supporting software needed by Census.

CircleCI Packagist PHP-Version

Installation & basic usage

  1. Install the opencensus/opencensus package using composer:

    $ composer require opencensus/opencensus:~0.2

    IMPORTANT: Please ensure your version is >= 0.2.0. There is a potential security vulnerability in < 0.2.0.

  2. [Optional]: Install the opencensus extension from PECL:

    $ pecl install opencensus-alpha

    Enable the extension in your php.ini:
  3. Initialize a tracer for your application:

    use OpenCensus\Trace\Tracer;
    use OpenCensus\Trace\Exporter\EchoExporter;
    Tracer::start(new EchoExporter());


To add tracing to a block of code, you can use the closure/callable form or explicitly open and close spans yourself.

Closure/Callable (preferred)

$pi = Tracer::inSpan(['name' => 'expensive-operation'], function() {
    // some expensive operation
    return calculatePi(1000);

$pi = Tracer::inSpan(['name' => 'expensive-operation'], 'calculatePi', [1000]);

Explicit Span Management

// Creates a detached span
$span = Tracer::startSpan(['name' => 'expensive-operation']);

// Opens a scope that attaches the span to the current context
$scope = Tracer::withSpan($span);
try {
    $pi = calculatePi(1000);
} finally {
    // Closes the scope (ends the span)



You can specify different samplers when initializing a tracer. The default sampler is the AlwaysSampleSampler which will attempt to trace all requests.

The provided samplers are:

Class Description
NeverSampleSampler Never trace any requests
AlwaysSampleSampler Trace all requests
MultiSampler Check multiple samplers
QpsSampler Trace X requests per second. Requires a PSR-6 cache implementation
ProbabilitySampler Trace X percent of requests.

If you would like to provide your own sampler, create a class that implements SamplerInterface.


You can choose different exporters to send the collected traces to.

The provided exporters are:

Class Description Dependency
EchoExporter Output the collected spans to stdout
FileExporter Output JSON encoded spans to a file
JaegerExporter Report traces to Jaeger server via Thrift over UDP opencensus/opencensus-exporter-jaeger
LoggerExporter Exporter JSON encoded spans to a PSR-3 logger
NullExporter No-op
OneLineEchoExporter Output the collected spans to stdout with one-line
StackdriverExporter Report traces to Google Cloud Stackdriver Trace opencensus/opencensus-exporter-stackdriver
ZipkinExporter Report collected spans to a Zipkin server opencensus/opencensus-exporter-zipkin

If you would like to provide your own reporter, create a class that implements ExporterInterface.



This library follows Semantic Versioning.

Please note it is currently under active development. Any release versioned 0.x.y is subject to backwards incompatible changes at any time.

GA: Libraries defined at a GA quality level are stable, and will not introduce backwards-incompatible changes in any minor or patch releases. We will address issues and requests with the highest priority.

Beta: Libraries defined at a Beta quality level are expected to be mostly stable and we're working towards their release candidate. We will address issues and requests with a higher priority.

Alpha: Libraries defined at an Alpha quality level are still a work-in-progress and are more likely to get backwards-incompatible updates.

Current Status: Alpha


Contributions to this library are always welcome and highly encouraged.

See CONTRIBUTING for more information on how to get started.


See RELEASING for more information on releasing new versions.


Apache 2.0 - See LICENSE for more information.


This is not an official Google product.