Configuring Blackfire Monitoring

Blackfire Profiler and Blackfire Monitoring use the same software stack. To get up and running, please follow the installation procedure.


A subscription to Blackfire Production is required to activate Monitoring + Alerting.

Read more on our pricing page.


Blackfire Monitoring currently supports PHP 7 and higher on Linux, BSD, macOS and Windows (via Windows Subsystem for Linux).

Python supports Python 2.7 and higher.

Activating Monitoring on an Environment

Once you have subscribed to Blackfire Monitoring, you should activate it on the relevant environment:

  • If your PHP probe version is older than 1.61.0, configure your php.ini file with blackfire.apm_enabled = 1;
  • Go to your organization menu and click on “Organization Monitoring Usage” item;
  • For each environment, you can Enable or Disable Monitoring.

This requires to have admin rights on the environments, or to be the subscription owner.


Since version 1.61.0 of the PHP Probe, Blackfire Monitoring is enabled by default.

You can disable it explicitly by configuring your php.ini file with blackfire.apm_enabled = 0;

Configuring Monitoring Settings

Sample Rate

The Sample Rate represents the percentage of your PHP requests which you would like Blackfire to monitor.

Each request which is monitored generates a “Trace”. This tracing level captures general performance metrics, such as overall response time and memory usage, and generates close-to-no overhead.

We highly recommend you to monitor at least 80% of your requests, but as Blackfire Monitoring pricing is based on a quota of Traces, you can balance:

  • changing your Trace Quota and control the subscription costs;
  • changing your Sample Rate and control the monitoring granularity.

Extended Sample Rate

The Extended Sample Rate represents the percentage of Traces for which Blackfire will collect more in-depth metrics.

Especially, such Extended Traces will include Spans.

A Span is the representation of a function call over time, just like in a profile timeline.

Collecting Spans may generate additional overhead on Extended Traces.

With the Extended Sample Rate, you can balance:

  • the number of end-user requests which may be impacted by the overhead;
  • the possibility for you to collect in-depth performance metrics with “real-world” context.


Blackfire Monitoring natively supports all PHP applications. For some frameworks, including Symfony, Drupal, Prestashop 1.7+, and Ibexa DXP, Blackfire Monitoring already collects the most significant Spans, while avoiding to add more than 15% overhead (maximum currently measured).