# Configuring Blackfire Monitoring

[introduction-to-blackfire](https://www.youtube-nocookie.com/embed/XKxe6NkJrYg?rel=0&showinfo=0&modestbranding=1&autoplay=0)

Blackfire Profiler and Blackfire Monitoring use [the same software stack](../reference-guide/faq#blackfire-stack). See how to [get started](../up-and-running/index).

> **Note**
>
> 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

To activate Blackfire Monitoring on an [environment](../reference-guide/environments), you need to be manager of that environment or an [organization admin](../up-and-running/access-management/environment-levels).

To activate Blackfire Monitoring on the relevant [environment](../reference-guide/environments):

1. Go to your organization menu and click [Organization Monitoring Usage](monitoring-usage#monitoring-activation).
2. Click **Enable**.

> **Note**
>
> Blackfire Monitoring is enabled by default since PHP Probe version `1.61.0`and Python Probe version `1.18.0`. Check the [PHP probe configuration](../php/configuration) and the [Python probe configuration](../php/configuration) if you want to explicitly disable it.

## 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](../profiling-cookbooks/understanding-timelines).

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.

> **Note**
>
> 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).