Added docs on avoiding duplicate HTTP spans when using OTEL

[jamescrosswell]

DESCRIBE YOUR PR

Resolves getsentry/sentry-dotnet#4670

IS YOUR CHANGE URGENT?

• None: Not urgent, can wait up to 1 week+

SLA

cc: @Flash0ver

PRE-MERGE CHECKLIST

Make sure you've checked the following before merging your changes:

• Checked Vercel preview for correctness, including links
• PR was reviewed and approved by any necessary SMEs (subject matter experts)
• PR was reviewed and approved by a member of the Sentry docs team

[vercel]

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Project	Deployment	Preview	Comments	Updated (UTC)
develop-docs	Ready	Preview	Comment	Nov 6, 2025 9:39pm
sentry-docs	Ready	Preview	Comment	Nov 6, 2025 9:39pm

[codecov]

Bundle Report

Changes will decrease total bundle size by 13.22kB (-0.06%) ⬇️. This is within the configured threshold ✅

Detailed changes

Bundle name	Size	Change
sentry-docs-client-array-push	10.16MB	-6 bytes (-0.0%) ⬇️
sentry-docs-server-cjs	12.92MB	-13.21kB (-0.1%) ⬇️

Affected Assets, Files, and Routes:

view changes for bundle: sentry-docs-client-array-push

Assets Changed:

Asset Name	Size Change	Total Size	Change (%)
static/chunks/pages/_app-*.js	-3 bytes	882.71kB	-0.0%
static/chunks/8321-*.js	-3 bytes	425.87kB	-0.0%
static/Zmgpq-*.js (New)	77 bytes	77 bytes	100.0% 🚀
static/Zmgpq-*.js (New)	684 bytes	684 bytes	100.0% 🚀
static/vgAVzbITWufmZ_YvgQqr2/_buildManifest.js (Deleted)	-684 bytes	0 bytes	-100.0% 🗑️
static/vgAVzbITWufmZ_YvgQqr2/_ssgManifest.js (Deleted)	-77 bytes	0 bytes	-100.0% 🗑️

view changes for bundle: sentry-docs-server-cjs

Assets Changed:

Asset Name	Size Change	Total Size	Change (%)
1729.js	-3 bytes	1.74MB	-0.0%
../instrumentation.js	-3 bytes	1.07MB	-0.0%
9523.js	-3 bytes	1.04MB	-0.0%
../app/[[...path]]/page.js.nft.json	-4.4kB	872.44kB	-0.5%
../app/platform-redirect/page.js.nft.json	-4.4kB	872.36kB	-0.5%
../app/sitemap.xml/route.js.nft.json	-4.4kB	869.59kB	-0.5%

[ericsampson]

What's the correct way to still use the SentryHttpFailedRequestHandler in this situation?

[jamescrosswell]

What's the correct way to still use the SentryHttpFailedRequestHandler in this situation?

@ericsampson you could disable the OTEL instrumentation for outbound HTTP requests.. so:

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddOpenTelemetry()
    .WithTracing(tracerProviderBuilder =>
        tracerProviderBuilder
            .AddAspNetCoreInstrumentation() // <-- Adds ASP.NET Core telemetry sources
-            .AddHttpClientInstrumentation() // <-- Adds HttpClient telemetry sources
            .AddSentry() // <-- Configure OpenTelemetry to send trace information to Sentry
    );

builder.WebHost.UseSentry(options =>
{
    options.Dsn = "...Your DSN...";
    options.SendDefaultPii = true;
    options.TracesSampleRate = 1.0;
    options.UseOpenTelemetry(); // <-- Configure Sentry to use OpenTelemetry trace information
-    options.DisableSentryHttpMessageHandler = true; // <-- Disable Sentry's HttpClient instrumentation to avoid duplicate spans
});

That way you still get features like failed request handling, that rely on the SentryHttpMessageHandler.

@Flash0ver we could look at changing this so it's possible to disable tracing for HTTP client requests without disabling the message handler entirely (and thus the error handling stuff).