[QUERY] Setting custom Sampler does not work with Azure Monitor Distro, alternatives?

[niravbhattsai]

Library name and version

Azure.Monitor.OpenTelemetry.AspNetCore 1.2.0

Query/Question

Hello Team,

Recently we moved from Application Insight SDK to Monitor Distro. Earlier we were using Adaptive Sampling but now that is not the case.

To mitigate this I created a Sampler of my Own.

`

public class MySampler(float samplingRate) : Sampler
{
private readonly Sampler _parentBasedSampler = new ParentBasedSampler(new TraceIdRatioBasedSampler(samplingRate));

public override SamplingResult ShouldSample(in SamplingParameters samplingParameters)
{
    var traceId = samplingParameters.TraceId;
    var name = samplingParameters.Name;
    var kind = samplingParameters.Kind;
    var attributes = samplingParameters.Tags;

    // Record all telemetry of request and exception type
    if (kind == ActivityKind.Server || kind == ActivityKind.Consumer || kind == ActivityKind.Producer)
    {
        return new SamplingResult(SamplingDecision.RecordAndSample);
    }

    // Record if any exception occurred in a trace
    if (attributes is not null && attributes.Any(attr => attr.Key == "otel.status_code" && attr.Value?.Equals("ERROR") == true))
    {
        return new SamplingResult(SamplingDecision.RecordAndSample);
    }

    // Record any activity/trace starting with name "my.prefix"
    if (name.StartsWith("my.prefix", StringComparison.OrdinalIgnoreCase))
    {
        return new SamplingResult(SamplingDecision.RecordAndSample);
    }

    // Sample remaining dependencies by a configured ratio
    return _parentBasedSampler.ShouldSample(samplingParameters);
}

}

`

However even if I set my Sampler with Open Telemetry, it gets overridden by the line in Distro Lib
`
public static TracerProviderBuilder AddAzureMonitorTraceExporter(
this TracerProviderBuilder builder,
Action configure = null,
TokenCredential credential = null,
string name = null)
{
// ...

var deferredBuilder = builder as IDeferredTracerProviderBuilder;
// ...

    builder.SetSampler(new ApplicationInsightsSampler(exporterOptions.SamplingRatio));
//...

}
`

Is there any alternative to set my own sampler?

Environment

.NET SDK:
Version: 9.0.200
Commit: 90e8b202f2
Workload version: 9.0.200-manifests.69179adf
MSBuild version: 17.13.8+cbc39bea8

Runtime Environment:
OS Name: Windows
OS Version: 10.0.22621
OS Platform: Windows
RID: win-x64
Base Path: C:\Program Files\dotnet\sdk\9.0.200\

.NET workloads installed:
[aspire]
Installation Source: VS 17.13.35825.156
Manifest Version: 8.2.2/8.0.100
Manifest Path: C:\Program Files\dotnet\sdk-manifests\8.0.100\microsoft.net.sdk.aspire\8.2.2\WorkloadManifest.json
Install Type: Msi

Configured to use loose manifests when installing new manifests.

Host:
Version: 9.0.2
Architecture: x64
Commit: 80aa709f5d

.NET SDKs installed:
6.0.428 [C:\Program Files\dotnet\sdk]
9.0.200 [C:\Program Files\dotnet\sdk]

.NET runtimes installed:
Microsoft.AspNetCore.App 6.0.36 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 7.0.20 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 8.0.13 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 9.0.2 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.NETCore.App 6.0.31 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 6.0.35 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 6.0.36 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 7.0.20 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 8.0.13 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 9.0.2 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.WindowsDesktop.App 6.0.31 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 6.0.35 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 6.0.36 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 7.0.20 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 8.0.13 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 9.0.2 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]

Other architectures found:
x86 [C:\Program Files (x86)\dotnet]
registered at [HKLM\SOFTWARE\dotnet\Setup\InstalledVersions\x86\InstallLocation]

Environment variables:
Not set

[github-actions]

Thanks for the feedback! We are routing this to the appropriate team for follow-up. cc @rajkumar-rangaraj @TimothyMothra.