# Running multiple profilers via the Microsoft CLR Instrumentation Engine

## Prerequisites for a multi-profiler setup <a href="#prerequisites-for-a-multi-profiler-setup" id="prerequisites-for-a-multi-profiler-setup"></a>

* 3rd party profiler is configured and supports Microsoft CLR Instrumentation technology. This can be verified by confirming the existence of the **MicrosoftInstrumentationEngine\_x64.dll** in your system.
* SeaLights environment variables are configured for the process or service from which coverage should be collected (see box at end of this page for a list)
* Identify the 3rd party provider's Profiler ID and DLL location

## Configuring the CLR Instrumentation Engine to support 2 profilers running simultaneously <a href="#configuring-the-clr-instrumentation-engine-to-support-2-profilers-running-simultaneously" id="configuring-the-clr-instrumentation-engine-to-support-2-profilers-running-simultaneously"></a>

Once we've confirmed our 3rd party profiler supports running with the CLR Instrumentation Engine, we will need to make some modifications:

1. Ensure the following environment variables are aligned:

   <pre data-overflow="wrap"><code>COR_PROFILER={324F817A-7420-4E6D-B3C1-143FBED6D855}
   COR_PROFILER_PATH_64=C:\&#x3C;path to where the file is>\MicrosoftInstrumentationEngine_x64.dll
   </code></pre>
2. Prepare an XML file to link the two profilers to be referenced in the next step. Please note the following:
   * The first entry refers to the 3rd party profiler, which should run alongside SeaLights.
   * The second entry refers to the SeaLights .NET profiler.
     * The SeaLights Profiler DLL can be x64 or x86 architecture, depending on the architecture of the process from which coverage should be collected
   * **Important: The path to each profiler DLL is relative to the location of this XML config file!**
     * Placing all referenced binaries in the same folder as the XML configuration file will ensure they can be found. *Sample XML is shared below*
3. Define 2 additional environment variables:

   <pre class="language-powershell" data-overflow="wrap"><code class="lang-powershell">MicrosoftInstrumentationEngine_ConfigPath64_=C:\&#x3C;Path to MSCLR XML Configuration file.xml>
   MicrosoftInstrumentationEngine_DisableCodeSignatureValidation=1
   </code></pre>
4. When the service is restarted, it will be running SeaLights along with the 3rd party profiler, which will both run under the Microsoft CLR Instrumentation Engine.

{% code title="MSCLR XML Configuration" overflow="wrap" lineNumbers="true" fullWidth="false" %}

```xml
 <InstrumentationEngineConfiguration>
    <InstrumentationMethod>
        <Name>VS Profiler</Name>
        <Description>Visual Studio Profiler</Description>
        <Module>VSPerfCorProf.dll</Module>
        <ClassGuid>{33708259-ba1b-4add-9de4-d4f280ea1223}</ClassGuid>
        <Priority>60</Priority>
    </InstrumentationMethod>
   
    <InstrumentationMethod>
        <Name>SL Profiler</Name>
        <Description>Sealights .NET profiler</Description>
        <Module>SL.DotNet.ProfilerLib_x64.dll</Module> OR <Module>SL.DotNet.ProfilerLib_x86.dll</Module>
        <ClassGuid>{01CA2C22-DC03-4FF5-8350-59E32A3536BA}</ClassGuid>
        <Priority>50</Priority>
    </InstrumentationMethod>
</InstrumentationEngineConfiguration>
```

{% endcode %}


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