SDK

The OpenTelemetry SDK provides a working implementation of the API, and can be set up and configured in a number of ways.

Manual setup

Setting up an SDK manually gives you the most control over the SDK’s configuration:

<?php
$exporter = new InMemoryExporter();
$meterProvider = new NoopMeterProvider();
$tracerProvider =  new TracerProvider(
    new BatchSpanProcessor(
        $exporter,
        ClockFactory::getDefault(),
        2048, //max queue size
        5000, //export timeout
        1024, //max batch size
        true, //auto flush
        $meterProvider
    )
);

SDK Builder

The SDK builder provides a convenient interface to configure parts of the SDK. However, it doesn’t support all of the features that manual setup does.

<?php

$spanExporter = new InMemoryExporter(); //mock exporter for demonstration purposes

$meterProvider = MeterProvider::builder()
    ->addReader(
        new ExportingReader(new MetricExporter((new StreamTransportFactory())->create(STDOUT, 'application/x-ndjson'), /*Temporality::CUMULATIVE*/))
    )
    ->build();

$tracerProvider = TracerProvider::builder()
    ->addSpanProcessor(
        (new BatchSpanProcessorBuilder($spanExporter))
            ->setMeterProvider($meterProvider)
            ->build()
    )
    ->build();

$loggerProvider = LoggerProvider::builder()
    ->addLogRecordProcessor(
        new SimpleLogsProcessor(
            (new ConsoleExporterFactory())->create()
        )
    )
    ->setResource(ResourceInfo::create(Attributes::create(['foo' => 'bar'])))
    ->build();

Sdk::builder()
    ->setTracerProvider($tracerProvider)
    ->setLoggerProvider($loggerProvider)
    ->setMeterProvider($meterProvider)
    ->setPropagator(TraceContextPropagator::getInstance())
    ->setAutoShutdown(true)
    ->buildAndRegisterGlobal();

Autoloading

If all configuration comes from environment variables (or php.ini), you can use SDK autoloading to automatically configure and globally register an SDK. The only requirement for this is that you set OTEL_PHP_AUTOLOAD_ENABLED=true, and provide any required/non-standard configuration as set out in SDK configuration.

For example:

OTEL_PHP_AUTOLOAD_ENABLED=true \
OTEL_EXPORTER_OTLP_PROTOCOL=grpc \
OTEL_EXPORTER_OTLP_ENDPOINT=http://collector:4317 \
php example.php

<?php
require 'vendor/autoload.php'; //sdk autoloading happens as part of composer initialization

$tracer = OpenTelemetry\API\Globals::tracerProvider()->getTracer('name', 'version', 'schema.url', [/*attributes*/]);
$meter = OpenTelemetry\API\Globals::meterProvider()->getMeter('name', 'version', 'schema.url', [/*attributes*/]);

SDK autoloading happens as part of the composer autoloader.

Excluded URLs

You can disable SDK autoloading if the request URL matches a regular expression. Matching an excluded URL prevents any telemetry from being generated or exported. You can use this feature in a shared-nothing PHP runtime like Apache or NGINX, for requests such as health checks.

For example, the following configuration turns off telemetry for requests such as https://site/client/123/info and https://site/xyz/healthcheck:

OTEL_PHP_EXCLUDED_URLS="client/.*/info,healthcheck"

Configuration

The PHP SDK supports most of the available configuration options. For conformance details, see the compliance matrix.

There are also a number of PHP-specific configurations:

Name	Default value	Values	Example	Description
`OTEL_PHP_TRACES_PROCESSOR`	`batch`	`batch`, `simple`	`simple`	Span processor selection
`OTEL_PHP_DETECTORS`	`all`	`env`, `host`, `os`, `process`, `process_runtime`, `sdk`, `sdk_provided`, `container`	`env,os,process`	Resource detector selection
`OTEL_PHP_AUTOLOAD_ENABLED`	`false`	`true`, `false`	`true`	Enable/disable SDK autoloading
`OTEL_PHP_LOG_DESTINATION`	`default`	`error_log`, `stderr`, `stdout`, `psr3`, `none`	`stderr`	Where internal errors and warnings will be sent
`OTEL_PHP_INTERNAL_METRICS_ENABLED`	`false`	`true`, `false`	`true`	Whether the SDK should emit metrics about its internal state (for example, batch processors)
`OTEL_PHP_DISABLED_INSTRUMENTATIONS`	`[]`	Instrumentation names, or `all`	`psr15,psr18`	Disable one or more installed auto-instrumentations
`OTEL_PHP_EXCLUDED_URLS`	``	Comma-delimited regular expression patterns	`client/.*/info,healthcheck`	Do not load the SDK if request URL matches one of the supplied regular expressions

Configurations can be provided as environment variables, or via php.ini (or a file included by php.ini)

Last modified February 8, 2024: document OTEL_PHP_EXCLUDED_URLS (#3952) (a52398df)