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Profiler chaining for the .NET Core agent

You can use profiler chaining to run the .NET Core agent alongside another .NET Core APM profiler.

The Contrast .NET Core agent is tested and proven to be compatible with the following profiling tools, given the combination of runtime, deployment type, and OS:

Profiling tool

Versions tested

.NET Core runtime

Third-party profiler deployment type

OS

AppDynamics

21.8.1

6.0

Installed, Nuget Package

Windows

Dynatrace One Agent

1.253.245

6.0

Installed

Windows, Linux

New Relic

8.23.107

6.0

NuGet Package

Windows, Linux

Riverbed SteelCentral Aternity APM

12.9.0

6.0

Installed

Windows

Datadog

2.35.0

6.0

Installed, NuGet Package

Windows, Linux

Note

The agent is likely compatible with other profiling tools if those tools follow the conventions of the CoreCLR Profiling API and do not make assumptions about the profiling environment.

Chaining is enabled by default and can be disabled by setting agent.dotnet.enable_chaining to false.

agent:
   dotnet:
     enable_chaining: false

Automatic (Windows and IIS)

When using the .NET Core installer for IIS, the installer configures chaining automatically for all hosted .NET Core applications.

  1. Install the third-party agent first (recommended), then the Contrast .NET Core agent.

  2. Restart the IIS workers (by default, this is done automatically by the agent installer). On restart, the Contrast .NET Core agent automatically detects the presence of other profiling tools registered with IIS and configures the environment to load both the Contrast .NET Core agent profiler and the third-party profiler.

Automatic (Linux)

Under Linux, automatic chaining may be configured by setting the LD_PRELOAD environment variable:

LD_PRELOAD=<path to the extracted Contrast files>/runtimes/linux-x64/native/ContrastChainLoader.so

For example, if the Contrast agent was extracted to /contrast, then the following would setup chaining automatically.

LD_PRELOAD=/contrast/runtimes/linux-x64/native/ContrastChainLoader.so dotnet ./HelloWorld

Some APM profilers already set LD_PRELOAD (e.g. Dynatrace). In this case, ensure the Contrast module is loaded first - separate LD_PRELOAD are delimited by colons :. For example:

LD_PRELOAD=/contrast/runtimes/linux-x64/native/ContrastChainLoader.so:/<path to Dynatrace>/liboneagentproc.so dotnet ./HelloWorld

Note

When running under Kubernetes, the Contrast Agent Operator will automatically setup chaining and is the preferred route to add agents to existing Kubernete workloads.

Manual

Chaining may need to be be manually setup, for example, in the following environments:

  • Hosted outside of IIS.

  • Environments that use the third-party agent's Nuget package (rather than the installed agent).

Note

Chaining with the Dynatrace agent is only supported using the automatic options above.

  1. Replace the CLR environment variables for the profiling tool with CONTRAST_CCC_CORECLR versions. Any of these names should be transformed:

    Change this

    To this

    CORECLR_PROFILER 

    CONTRAST_CCC_CORECLR_PROFILER

    CORECLR_PROFILER_PATH

    CONTRAST_CCC_CORECLR_PROFILER_PATH

    CORECLR_PROFILER_PATH_32

    CONTRAST_CCC_CORECLR_PROFILER_PATH_32

    CORECLR_PROFILER_PATH_64

    CONTRAST_CCC_CORECLR_PROFILER_PATH_64

  2. Then add the agent manually.

In this section: