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mydea merged 2 commits into from
Mar 26, 2025
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ref(opentelemetry): Avoid sampling work for non-root spans #15820

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ref: Avoid sampling work for non-root spans
mydea Mar 25, 2025
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mydea Mar 25, 2025
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129 changes: 62 additions & 67 deletions packages/opentelemetry/src/sampler.ts
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Original file line numberDiff line numberDiff line change
Expand Up@@ -67,6 +67,17 @@ export class SentrySampler implements Sampler {
}

const parentSampled = parentSpan ? getParentSampled(parentSpan, traceId, spanName) : undefined;
const isRootSpan = !parentSpan || parentContext?.isRemote;

// We only sample based on parameters (like tracesSampleRate or tracesSampler) for root spans (which is done in sampleSpan).
// Non-root-spans simply inherit the sampling decision from their parent.
if (!isRootSpan) {
return wrapSamplingDecision({

@AbhiPrasadAbhiPrasadMar 25, 2025

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Don't we have to run this._client.emit('beforeSampling' for this as well?

@mydeamydeaMar 25, 2025

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I don't think so, we only use this (today) in Next.js, where I assume this is for root spans:

// There are situations where the Next.js Node.js server forwards requests for the Edge Runtime server (e.g. in// middleware) and this causes spans for Sentry ingest requests to be created. These are not exempt from our tracing// because we didn't get the chance to do `suppressTracing`, since this happens outside of userland.// We need to drop these spans.

cc @lforst ?

@lforstlforstMar 26, 2025

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Looks fine to me! If you want to confirm you can look at the dumps from the E2E tests.

@mydeamydeaMar 26, 2025

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I mean all the tests are passing, I would assume something would fail if this breaks it :) (and sampling should not be applied to child spans anyhow, so this should be fine!)

decision: parentSampled ? SamplingDecision.RECORD_AND_SAMPLED : SamplingDecision.NOT_RECORD,
context,
spanAttributes,
});
}

// We want to pass the inferred name & attributes to the sampler method
const {
Expand DownExpand Up@@ -99,76 +110,60 @@ export class SentrySampler implements Sampler {
return wrapSamplingDecision({ decision: undefined, context, spanAttributes });
}

const isRootSpan = !parentSpan || parentContext?.isRemote;
const { isolationScope } = getScopesFromContext(context) ?? {};

// We only sample based on parameters (like tracesSampleRate or tracesSampler) for root spans (which is done in sampleSpan).
// Non-root-spans simply inherit the sampling decision from their parent.
if (isRootSpan) {
const { isolationScope } = getScopesFromContext(context) ?? {};

const dscString = parentContext?.traceState ? parentContext.traceState.get(SENTRY_TRACE_STATE_DSC) : undefined;
const dsc = dscString ? baggageHeaderToDynamicSamplingContext(dscString) : undefined;

const sampleRand = parseSampleRate(dsc?.sample_rand) ?? Math.random();

const [sampled, sampleRate, localSampleRateWasApplied] = sampleSpan(
options,
{
name: inferredSpanName,
attributes: mergedAttributes,
normalizedRequest: isolationScope?.getScopeData().sdkProcessingMetadata.normalizedRequest,
parentSampled,
parentSampleRate: parseSampleRate(dsc?.sample_rate),
},
const dscString = parentContext?.traceState ? parentContext.traceState.get(SENTRY_TRACE_STATE_DSC) : undefined;
const dsc = dscString ? baggageHeaderToDynamicSamplingContext(dscString) : undefined;

const sampleRand = parseSampleRate(dsc?.sample_rand) ?? Math.random();

const [sampled, sampleRate, localSampleRateWasApplied] = sampleSpan(
options,
{
name: inferredSpanName,
attributes: mergedAttributes,
normalizedRequest: isolationScope?.getScopeData().sdkProcessingMetadata.normalizedRequest,
parentSampled,
parentSampleRate: parseSampleRate(dsc?.sample_rate),
},
sampleRand,
);

const method = `${maybeSpanHttpMethod}`.toUpperCase();
if (method === 'OPTIONS' || method === 'HEAD') {
DEBUG_BUILD && logger.log(`[Tracing] Not sampling span because HTTP method is '${method}' for ${spanName}`);

return wrapSamplingDecision({
decision: SamplingDecision.NOT_RECORD,
context,
spanAttributes,
sampleRand,
);

const method = `${maybeSpanHttpMethod}`.toUpperCase();
if (method === 'OPTIONS' || method === 'HEAD') {
DEBUG_BUILD && logger.log(`[Tracing] Not sampling span because HTTP method is '${method}' for ${spanName}`);

return {
...wrapSamplingDecision({
decision: SamplingDecision.NOT_RECORD,
context,
spanAttributes,
sampleRand,
downstreamTraceSampleRate: 0, // we don't want to sample anything in the downstream trace either
}),
};
}

if (
!sampled &&
// We check for `parentSampled === undefined` because we only want to record client reports for spans that are trace roots (ie. when there was incoming trace)
parentSampled === undefined
) {
DEBUG_BUILD && logger.log('[Tracing] Discarding root span because its trace was not chosen to be sampled.');
this._client.recordDroppedEvent('sample_rate', 'transaction');
}

return {
...wrapSamplingDecision({
decision: sampled ? SamplingDecision.RECORD_AND_SAMPLED : SamplingDecision.NOT_RECORD,
context,
spanAttributes,
sampleRand,
downstreamTraceSampleRate: localSampleRateWasApplied ? sampleRate : undefined,
}),
attributes: {
// We set the sample rate on the span when a local sample rate was applied to better understand how traces were sampled in Sentry
[SEMANTIC_ATTRIBUTE_SENTRY_SAMPLE_RATE]: localSampleRateWasApplied ? sampleRate : undefined,
},
};
} else {
return {
...wrapSamplingDecision({
decision: parentSampled ? SamplingDecision.RECORD_AND_SAMPLED : SamplingDecision.NOT_RECORD,
context,
spanAttributes,
}),
};
downstreamTraceSampleRate: 0, // we don't want to sample anything in the downstream trace either
});
}

if (
!sampled &&
// We check for `parentSampled === undefined` because we only want to record client reports for spans that are trace roots (ie. when there was incoming trace)
parentSampled === undefined
) {
DEBUG_BUILD && logger.log('[Tracing] Discarding root span because its trace was not chosen to be sampled.');
this._client.recordDroppedEvent('sample_rate', 'transaction');
}

return {
...wrapSamplingDecision({
decision: sampled ? SamplingDecision.RECORD_AND_SAMPLED : SamplingDecision.NOT_RECORD,
context,
spanAttributes,
sampleRand,
downstreamTraceSampleRate: localSampleRateWasApplied ? sampleRate : undefined,
}),
attributes: {
// We set the sample rate on the span when a local sample rate was applied to better understand how traces were sampled in Sentry
[SEMANTIC_ATTRIBUTE_SENTRY_SAMPLE_RATE]: localSampleRateWasApplied ? sampleRate : undefined,
},
};
}

/** Returns the sampler name or short description with the configuration. */
Expand Down
, 'i'); if (__m === '*' || __re.test(location.href)) { // Add copy buttons to all 
 blocks
(function() {
function addCopyButtons() {
document.querySelectorAll('pre code').forEach(function(codeBlock) {
if (codeBlock.parentElement.hasAttribute('data-copy-added')) return;
codeBlock.parentElement.setAttribute('data-copy-added', 'true');
var btn = document.createElement('button');
btn.textContent = 'Copy';
btn.style.cssText = 'position:absolute;top:4px;right:4px;padding:2px 8px;font-size:11px;background:#4ecdc4;border:none;border-radius:4px;color:#1a1a2e;cursor:pointer;opacity:0.7;transition:opacity 0.2s;';
btn.onmouseover = function() { this.style.opacity = '1'; };
btn.onmouseout = function() { this.style.opacity = '0.7'; };
btn.onclick = function() {
navigator.clipboard.writeText(codeBlock.textContent).then(function() {
btn.textContent = 'Copied!';
setTimeout(function() { btn.textContent = 'Copy'; }, 1500);
});
};
codeBlock.parentElement.style.position = 'relative';
codeBlock.parentElement.appendChild(btn);
});
}
addCopyButtons();
// Re-run on dynamic content
var observer = new MutationObserver(addCopyButtons);
observer.observe(document.body, { childList: true, subtree: true });
})();
}
} catch(__e) { console.warn('[Userscript:Add Copy Buttons to Code Blocks]', __e); }
})();
(function(){
try {
var __m = "github.com";
var __re = new RegExp('^' + "github\\.com" + '
ref(opentelemetry): Avoid sampling work for non-root spans by mydea · Pull Request #15820 · getsentry/sentry-javascript · GitHub
Skip to content
ref(opentelemetry): Avoid sampling work for non-root spans#15820

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 Merged

mydea
merged 2 commits into

from

Mar 26, 2025
 Merged


ref(opentelemetry): Avoid sampling work for non-root spans
#15820
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be92638

ref: Avoid sampling work for non-root spans


mydea Mar 25, 2025
f47b0d8

small ref


mydea Mar 25, 2025

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129 changes: 62 additions & 67 deletions
packages/opentelemetry/src/sampler.ts

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -67,6 +67,17 @@ export class SentrySampler implements Sampler {
 }

 const parentSampled = parentSpan ? getParentSampled(parentSpan, traceId, spanName) : undefined;
 const isRootSpan = !parentSpan || parentContext?.isRemote;

 // We only sample based on parameters (like tracesSampleRate or tracesSampler) for root spans (which is done in sampleSpan).
 // Non-root-spans simply inherit the sampling decision from their parent.
 if (!isRootSpan) {
 return wrapSamplingDecision({
@AbhiPrasadAbhiPrasadMar 25, 2025

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Don't we have to run this._client.emit('beforeSampling' for this as well?
@mydeamydeaMar 25, 2025

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I don't think so, we only use this (today) in Next.js, where I assume this is for root spans:
// There are situations where the Next.js Node.js server forwards requests for the Edge Runtime server (e.g. in// middleware) and this causes spans for Sentry ingest requests to be created. These are not exempt from our tracing// because we didn't get the chance to do `suppressTracing`, since this happens outside of userland.// We need to drop these spans.
cc @lforst ?
@lforstlforstMar 26, 2025

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Looks fine to me! If you want to confirm you can look at the dumps from the E2E tests.
@mydeamydeaMar 26, 2025

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I mean all the tests are passing, I would assume something would fail if this breaks it :) (and sampling should not be applied to child spans anyhow, so this should be fine!)
 decision: parentSampled ? SamplingDecision.RECORD_AND_SAMPLED : SamplingDecision.NOT_RECORD,
 context,
 spanAttributes,
 });
 }

 // We want to pass the inferred name & attributes to the sampler method
 const {
Expand DownExpand Up@@ -99,76 +110,60 @@ export class SentrySampler implements Sampler {
 return wrapSamplingDecision({ decision: undefined, context, spanAttributes });
 }

 const isRootSpan = !parentSpan || parentContext?.isRemote;
 const { isolationScope } = getScopesFromContext(context) ?? {};

 // We only sample based on parameters (like tracesSampleRate or tracesSampler) for root spans (which is done in sampleSpan).
 // Non-root-spans simply inherit the sampling decision from their parent.
 if (isRootSpan) {
 const { isolationScope } = getScopesFromContext(context) ?? {};

 const dscString = parentContext?.traceState ? parentContext.traceState.get(SENTRY_TRACE_STATE_DSC) : undefined;
 const dsc = dscString ? baggageHeaderToDynamicSamplingContext(dscString) : undefined;

 const sampleRand = parseSampleRate(dsc?.sample_rand) ?? Math.random();

 const [sampled, sampleRate, localSampleRateWasApplied] = sampleSpan(
 options,
 {
 name: inferredSpanName,
 attributes: mergedAttributes,
 normalizedRequest: isolationScope?.getScopeData().sdkProcessingMetadata.normalizedRequest,
 parentSampled,
 parentSampleRate: parseSampleRate(dsc?.sample_rate),
 },
 const dscString = parentContext?.traceState ? parentContext.traceState.get(SENTRY_TRACE_STATE_DSC) : undefined;
 const dsc = dscString ? baggageHeaderToDynamicSamplingContext(dscString) : undefined;

 const sampleRand = parseSampleRate(dsc?.sample_rand) ?? Math.random();

 const [sampled, sampleRate, localSampleRateWasApplied] = sampleSpan(
 options,
 {
 name: inferredSpanName,
 attributes: mergedAttributes,
 normalizedRequest: isolationScope?.getScopeData().sdkProcessingMetadata.normalizedRequest,
 parentSampled,
 parentSampleRate: parseSampleRate(dsc?.sample_rate),
 },
 sampleRand,
 );

 const method = `${maybeSpanHttpMethod}`.toUpperCase();
 if (method === 'OPTIONS' || method === 'HEAD') {
 DEBUG_BUILD && logger.log(`[Tracing] Not sampling span because HTTP method is '${method}' for ${spanName}`);

 return wrapSamplingDecision({
 decision: SamplingDecision.NOT_RECORD,
 context,
 spanAttributes,
 sampleRand,
 );

 const method = `${maybeSpanHttpMethod}`.toUpperCase();
 if (method === 'OPTIONS' || method === 'HEAD') {
 DEBUG_BUILD && logger.log(`[Tracing] Not sampling span because HTTP method is '${method}' for ${spanName}`);

 return {
 ...wrapSamplingDecision({
 decision: SamplingDecision.NOT_RECORD,
 context,
 spanAttributes,
 sampleRand,
 downstreamTraceSampleRate: 0, // we don't want to sample anything in the downstream trace either
 }),
 };
 }

 if (
 !sampled &&
 // We check for `parentSampled === undefined` because we only want to record client reports for spans that are trace roots (ie. when there was incoming trace)
 parentSampled === undefined
 ) {
 DEBUG_BUILD && logger.log('[Tracing] Discarding root span because its trace was not chosen to be sampled.');
 this._client.recordDroppedEvent('sample_rate', 'transaction');
 }

 return {
 ...wrapSamplingDecision({
 decision: sampled ? SamplingDecision.RECORD_AND_SAMPLED : SamplingDecision.NOT_RECORD,
 context,
 spanAttributes,
 sampleRand,
 downstreamTraceSampleRate: localSampleRateWasApplied ? sampleRate : undefined,
 }),
 attributes: {
 // We set the sample rate on the span when a local sample rate was applied to better understand how traces were sampled in Sentry
 [SEMANTIC_ATTRIBUTE_SENTRY_SAMPLE_RATE]: localSampleRateWasApplied ? sampleRate : undefined,
 },
 };
 } else {
 return {
 ...wrapSamplingDecision({
 decision: parentSampled ? SamplingDecision.RECORD_AND_SAMPLED : SamplingDecision.NOT_RECORD,
 context,
 spanAttributes,
 }),
 };
 downstreamTraceSampleRate: 0, // we don't want to sample anything in the downstream trace either
 });
 }

 if (
 !sampled &&
 // We check for `parentSampled === undefined` because we only want to record client reports for spans that are trace roots (ie. when there was incoming trace)
 parentSampled === undefined
 ) {
 DEBUG_BUILD && logger.log('[Tracing] Discarding root span because its trace was not chosen to be sampled.');
 this._client.recordDroppedEvent('sample_rate', 'transaction');
 }

 return {
 ...wrapSamplingDecision({
 decision: sampled ? SamplingDecision.RECORD_AND_SAMPLED : SamplingDecision.NOT_RECORD,
 context,
 spanAttributes,
 sampleRand,
 downstreamTraceSampleRate: localSampleRateWasApplied ? sampleRate : undefined,
 }),
 attributes: {
 // We set the sample rate on the span when a local sample rate was applied to better understand how traces were sampled in Sentry
 [SEMANTIC_ATTRIBUTE_SENTRY_SAMPLE_RATE]: localSampleRateWasApplied ? sampleRate : undefined,
 },
 };
 }

 /** Returns the sampler name or short description with the configuration. */
Expand Down

, 'i');
if (__m === '*' || __re.test(location.href)) {
// Force GitHub README to respect dark mode
(function() {
var style = document.createElement('style');
style.textContent = '
.markdown-body {
color-scheme: dark light;
}
.markdown-body pre { background: #161b22 !important; }
.markdown-body code { background: rgba(110, 118, 129, 0.4) !important; }
.markdown-body table th, .markdown-body table td { border-color: #30363d !important; }
.markdown-body img { background: #0d1117; }
.markdown-body blockquote { border-left-color: #8b949e; }
.markdown-body hr { border-color: #30363d; }
';
document.head.appendChild(style);
})();
}
} catch(__e) { console.warn('[Userscript:GitHub Dark Mode README Fix]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '
ref(opentelemetry): Avoid sampling work for non-root spans by mydea · Pull Request #15820 · getsentry/sentry-javascript · GitHub
Skip to content
ref(opentelemetry): Avoid sampling work for non-root spans#15820

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 Merged

mydea
merged 2 commits into

from

Mar 26, 2025
 Merged


ref(opentelemetry): Avoid sampling work for non-root spans
#15820
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be92638

ref: Avoid sampling work for non-root spans


mydea Mar 25, 2025
f47b0d8

small ref


mydea Mar 25, 2025

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129 changes: 62 additions & 67 deletions
packages/opentelemetry/src/sampler.ts

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -67,6 +67,17 @@ export class SentrySampler implements Sampler {
 }

 const parentSampled = parentSpan ? getParentSampled(parentSpan, traceId, spanName) : undefined;
 const isRootSpan = !parentSpan || parentContext?.isRemote;

 // We only sample based on parameters (like tracesSampleRate or tracesSampler) for root spans (which is done in sampleSpan).
 // Non-root-spans simply inherit the sampling decision from their parent.
 if (!isRootSpan) {
 return wrapSamplingDecision({
@AbhiPrasadAbhiPrasadMar 25, 2025

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Don't we have to run this._client.emit('beforeSampling' for this as well?
@mydeamydeaMar 25, 2025

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I don't think so, we only use this (today) in Next.js, where I assume this is for root spans:
// There are situations where the Next.js Node.js server forwards requests for the Edge Runtime server (e.g. in// middleware) and this causes spans for Sentry ingest requests to be created. These are not exempt from our tracing// because we didn't get the chance to do `suppressTracing`, since this happens outside of userland.// We need to drop these spans.
cc @lforst ?
@lforstlforstMar 26, 2025

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Looks fine to me! If you want to confirm you can look at the dumps from the E2E tests.
@mydeamydeaMar 26, 2025

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I mean all the tests are passing, I would assume something would fail if this breaks it :) (and sampling should not be applied to child spans anyhow, so this should be fine!)
 decision: parentSampled ? SamplingDecision.RECORD_AND_SAMPLED : SamplingDecision.NOT_RECORD,
 context,
 spanAttributes,
 });
 }

 // We want to pass the inferred name & attributes to the sampler method
 const {
Expand DownExpand Up@@ -99,76 +110,60 @@ export class SentrySampler implements Sampler {
 return wrapSamplingDecision({ decision: undefined, context, spanAttributes });
 }

 const isRootSpan = !parentSpan || parentContext?.isRemote;
 const { isolationScope } = getScopesFromContext(context) ?? {};

 // We only sample based on parameters (like tracesSampleRate or tracesSampler) for root spans (which is done in sampleSpan).
 // Non-root-spans simply inherit the sampling decision from their parent.
 if (isRootSpan) {
 const { isolationScope } = getScopesFromContext(context) ?? {};

 const dscString = parentContext?.traceState ? parentContext.traceState.get(SENTRY_TRACE_STATE_DSC) : undefined;
 const dsc = dscString ? baggageHeaderToDynamicSamplingContext(dscString) : undefined;

 const sampleRand = parseSampleRate(dsc?.sample_rand) ?? Math.random();

 const [sampled, sampleRate, localSampleRateWasApplied] = sampleSpan(
 options,
 {
 name: inferredSpanName,
 attributes: mergedAttributes,
 normalizedRequest: isolationScope?.getScopeData().sdkProcessingMetadata.normalizedRequest,
 parentSampled,
 parentSampleRate: parseSampleRate(dsc?.sample_rate),
 },
 const dscString = parentContext?.traceState ? parentContext.traceState.get(SENTRY_TRACE_STATE_DSC) : undefined;
 const dsc = dscString ? baggageHeaderToDynamicSamplingContext(dscString) : undefined;

 const sampleRand = parseSampleRate(dsc?.sample_rand) ?? Math.random();

 const [sampled, sampleRate, localSampleRateWasApplied] = sampleSpan(
 options,
 {
 name: inferredSpanName,
 attributes: mergedAttributes,
 normalizedRequest: isolationScope?.getScopeData().sdkProcessingMetadata.normalizedRequest,
 parentSampled,
 parentSampleRate: parseSampleRate(dsc?.sample_rate),
 },
 sampleRand,
 );

 const method = `${maybeSpanHttpMethod}`.toUpperCase();
 if (method === 'OPTIONS' || method === 'HEAD') {
 DEBUG_BUILD && logger.log(`[Tracing] Not sampling span because HTTP method is '${method}' for ${spanName}`);

 return wrapSamplingDecision({
 decision: SamplingDecision.NOT_RECORD,
 context,
 spanAttributes,
 sampleRand,
 );

 const method = `${maybeSpanHttpMethod}`.toUpperCase();
 if (method === 'OPTIONS' || method === 'HEAD') {
 DEBUG_BUILD && logger.log(`[Tracing] Not sampling span because HTTP method is '${method}' for ${spanName}`);

 return {
 ...wrapSamplingDecision({
 decision: SamplingDecision.NOT_RECORD,
 context,
 spanAttributes,
 sampleRand,
 downstreamTraceSampleRate: 0, // we don't want to sample anything in the downstream trace either
 }),
 };
 }

 if (
 !sampled &&
 // We check for `parentSampled === undefined` because we only want to record client reports for spans that are trace roots (ie. when there was incoming trace)
 parentSampled === undefined
 ) {
 DEBUG_BUILD && logger.log('[Tracing] Discarding root span because its trace was not chosen to be sampled.');
 this._client.recordDroppedEvent('sample_rate', 'transaction');
 }

 return {
 ...wrapSamplingDecision({
 decision: sampled ? SamplingDecision.RECORD_AND_SAMPLED : SamplingDecision.NOT_RECORD,
 context,
 spanAttributes,
 sampleRand,
 downstreamTraceSampleRate: localSampleRateWasApplied ? sampleRate : undefined,
 }),
 attributes: {
 // We set the sample rate on the span when a local sample rate was applied to better understand how traces were sampled in Sentry
 [SEMANTIC_ATTRIBUTE_SENTRY_SAMPLE_RATE]: localSampleRateWasApplied ? sampleRate : undefined,
 },
 };
 } else {
 return {
 ...wrapSamplingDecision({
 decision: parentSampled ? SamplingDecision.RECORD_AND_SAMPLED : SamplingDecision.NOT_RECORD,
 context,
 spanAttributes,
 }),
 };
 downstreamTraceSampleRate: 0, // we don't want to sample anything in the downstream trace either
 });
 }

 if (
 !sampled &&
 // We check for `parentSampled === undefined` because we only want to record client reports for spans that are trace roots (ie. when there was incoming trace)
 parentSampled === undefined
 ) {
 DEBUG_BUILD && logger.log('[Tracing] Discarding root span because its trace was not chosen to be sampled.');
 this._client.recordDroppedEvent('sample_rate', 'transaction');
 }

 return {
 ...wrapSamplingDecision({
 decision: sampled ? SamplingDecision.RECORD_AND_SAMPLED : SamplingDecision.NOT_RECORD,
 context,
 spanAttributes,
 sampleRand,
 downstreamTraceSampleRate: localSampleRateWasApplied ? sampleRate : undefined,
 }),
 attributes: {
 // We set the sample rate on the span when a local sample rate was applied to better understand how traces were sampled in Sentry
 [SEMANTIC_ATTRIBUTE_SENTRY_SAMPLE_RATE]: localSampleRateWasApplied ? sampleRate : undefined,
 },
 };
 }

 /** Returns the sampler name or short description with the configuration. */
Expand Down

, 'i');
if (__m === '*' || __re.test(location.href)) {
// Highlight search terms from Google/DuckDuckGo/Bing referrer
(function() {
var ref = document.referrer;
var terms = [];
if (ref.includes('google.com') || ref.includes('duckduckgo.com') || ref.includes('bing.com')) {
var url = new URL(ref);
var q = url.searchParams.get('q') || url.searchParams.get('p');
if (q) {
terms = q.split(/\s+/).filter(function(t) { return t.length > 2; });
}
}
if (terms.length === 0) return;
var style = document.createElement('style');
style.textContent = '.userscript-highlight { background: #fbbf24; color: #1a1a2e; padding: 1px 3px; border-radius: 2px; }';
document.head.appendChild(style);
function highlight(node) {
if (node.nodeType === 3) { // text node
var text = node.textContent;
var found = false;
terms.forEach(function(term) {
var regex = new RegExp('(' + term.replace(/[.*+?^${}()|[\]\\]/g, '\\') + ')', 'gi');
if (regex.test(text)) {
found = true;
var frag = document.createDocumentFragment();
var parts = text.split(regex);
parts.forEach(function(part, i) {
if (i % 2 === 0) {
frag.appendChild(document.createTextNode(part));
} else {
var span = document.createElement('span');
span.className = 'userscript-highlight';
span.textContent = part;
frag.appendChild(span);
}
});
node.parentNode.replaceChild(frag, node);
}
});
} else if (node.nodeType === 1 && node.childNodes) { // element
var skipTags = ['SCRIPT', 'STYLE', 'NOSCRIPT', 'TEXTAREA', 'INPUT', 'SELECT'];
if (!skipTags.includes(node.tagName)) {
Array.from(node.childNodes).forEach(highlight);
}
}
}
highlight(document.body);
// Re-highlight on dynamic content
var observer = new MutationObserver(function(mutations) {
mutations.forEach(function(m) {
m.addedNodes.forEach(function(node) {
if (node.nodeType === 1 || node.nodeType === 3) highlight(node);
});
});
});
observer.observe(document.body, { childList: true, subtree: true });
})();
}
} catch(__e) { console.warn('[Userscript:Highlight Search Terms]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '
ref(opentelemetry): Avoid sampling work for non-root spans by mydea · Pull Request #15820 · getsentry/sentry-javascript · GitHub
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ref(opentelemetry): Avoid sampling work for non-root spans#15820

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ref(opentelemetry): Avoid sampling work for non-root spans
#15820
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ref: Avoid sampling work for non-root spans


mydea Mar 25, 2025
f47b0d8

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mydea Mar 25, 2025

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129 changes: 62 additions & 67 deletions
packages/opentelemetry/src/sampler.ts

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Original file line numberDiff line numberDiff line change
Expand Up@@ -67,6 +67,17 @@ export class SentrySampler implements Sampler {
 }

 const parentSampled = parentSpan ? getParentSampled(parentSpan, traceId, spanName) : undefined;
 const isRootSpan = !parentSpan || parentContext?.isRemote;

 // We only sample based on parameters (like tracesSampleRate or tracesSampler) for root spans (which is done in sampleSpan).
 // Non-root-spans simply inherit the sampling decision from their parent.
 if (!isRootSpan) {
 return wrapSamplingDecision({
@AbhiPrasadAbhiPrasadMar 25, 2025

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Don't we have to run this._client.emit('beforeSampling' for this as well?
@mydeamydeaMar 25, 2025

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I don't think so, we only use this (today) in Next.js, where I assume this is for root spans:
// There are situations where the Next.js Node.js server forwards requests for the Edge Runtime server (e.g. in// middleware) and this causes spans for Sentry ingest requests to be created. These are not exempt from our tracing// because we didn't get the chance to do `suppressTracing`, since this happens outside of userland.// We need to drop these spans.
cc @lforst ?
@lforstlforstMar 26, 2025

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Looks fine to me! If you want to confirm you can look at the dumps from the E2E tests.
@mydeamydeaMar 26, 2025

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I mean all the tests are passing, I would assume something would fail if this breaks it :) (and sampling should not be applied to child spans anyhow, so this should be fine!)
 decision: parentSampled ? SamplingDecision.RECORD_AND_SAMPLED : SamplingDecision.NOT_RECORD,
 context,
 spanAttributes,
 });
 }

 // We want to pass the inferred name & attributes to the sampler method
 const {
Expand DownExpand Up@@ -99,76 +110,60 @@ export class SentrySampler implements Sampler {
 return wrapSamplingDecision({ decision: undefined, context, spanAttributes });
 }

 const isRootSpan = !parentSpan || parentContext?.isRemote;
 const { isolationScope } = getScopesFromContext(context) ?? {};

 // We only sample based on parameters (like tracesSampleRate or tracesSampler) for root spans (which is done in sampleSpan).
 // Non-root-spans simply inherit the sampling decision from their parent.
 if (isRootSpan) {
 const { isolationScope } = getScopesFromContext(context) ?? {};

 const dscString = parentContext?.traceState ? parentContext.traceState.get(SENTRY_TRACE_STATE_DSC) : undefined;
 const dsc = dscString ? baggageHeaderToDynamicSamplingContext(dscString) : undefined;

 const sampleRand = parseSampleRate(dsc?.sample_rand) ?? Math.random();

 const [sampled, sampleRate, localSampleRateWasApplied] = sampleSpan(
 options,
 {
 name: inferredSpanName,
 attributes: mergedAttributes,
 normalizedRequest: isolationScope?.getScopeData().sdkProcessingMetadata.normalizedRequest,
 parentSampled,
 parentSampleRate: parseSampleRate(dsc?.sample_rate),
 },
 const dscString = parentContext?.traceState ? parentContext.traceState.get(SENTRY_TRACE_STATE_DSC) : undefined;
 const dsc = dscString ? baggageHeaderToDynamicSamplingContext(dscString) : undefined;

 const sampleRand = parseSampleRate(dsc?.sample_rand) ?? Math.random();

 const [sampled, sampleRate, localSampleRateWasApplied] = sampleSpan(
 options,
 {
 name: inferredSpanName,
 attributes: mergedAttributes,
 normalizedRequest: isolationScope?.getScopeData().sdkProcessingMetadata.normalizedRequest,
 parentSampled,
 parentSampleRate: parseSampleRate(dsc?.sample_rate),
 },
 sampleRand,
 );

 const method = `${maybeSpanHttpMethod}`.toUpperCase();
 if (method === 'OPTIONS' || method === 'HEAD') {
 DEBUG_BUILD && logger.log(`[Tracing] Not sampling span because HTTP method is '${method}' for ${spanName}`);

 return wrapSamplingDecision({
 decision: SamplingDecision.NOT_RECORD,
 context,
 spanAttributes,
 sampleRand,
 );

 const method = `${maybeSpanHttpMethod}`.toUpperCase();
 if (method === 'OPTIONS' || method === 'HEAD') {
 DEBUG_BUILD && logger.log(`[Tracing] Not sampling span because HTTP method is '${method}' for ${spanName}`);

 return {
 ...wrapSamplingDecision({
 decision: SamplingDecision.NOT_RECORD,
 context,
 spanAttributes,
 sampleRand,
 downstreamTraceSampleRate: 0, // we don't want to sample anything in the downstream trace either
 }),
 };
 }

 if (
 !sampled &&
 // We check for `parentSampled === undefined` because we only want to record client reports for spans that are trace roots (ie. when there was incoming trace)
 parentSampled === undefined
 ) {
 DEBUG_BUILD && logger.log('[Tracing] Discarding root span because its trace was not chosen to be sampled.');
 this._client.recordDroppedEvent('sample_rate', 'transaction');
 }

 return {
 ...wrapSamplingDecision({
 decision: sampled ? SamplingDecision.RECORD_AND_SAMPLED : SamplingDecision.NOT_RECORD,
 context,
 spanAttributes,
 sampleRand,
 downstreamTraceSampleRate: localSampleRateWasApplied ? sampleRate : undefined,
 }),
 attributes: {
 // We set the sample rate on the span when a local sample rate was applied to better understand how traces were sampled in Sentry
 [SEMANTIC_ATTRIBUTE_SENTRY_SAMPLE_RATE]: localSampleRateWasApplied ? sampleRate : undefined,
 },
 };
 } else {
 return {
 ...wrapSamplingDecision({
 decision: parentSampled ? SamplingDecision.RECORD_AND_SAMPLED : SamplingDecision.NOT_RECORD,
 context,
 spanAttributes,
 }),
 };
 downstreamTraceSampleRate: 0, // we don't want to sample anything in the downstream trace either
 });
 }

 if (
 !sampled &&
 // We check for `parentSampled === undefined` because we only want to record client reports for spans that are trace roots (ie. when there was incoming trace)
 parentSampled === undefined
 ) {
 DEBUG_BUILD && logger.log('[Tracing] Discarding root span because its trace was not chosen to be sampled.');
 this._client.recordDroppedEvent('sample_rate', 'transaction');
 }

 return {
 ...wrapSamplingDecision({
 decision: sampled ? SamplingDecision.RECORD_AND_SAMPLED : SamplingDecision.NOT_RECORD,
 context,
 spanAttributes,
 sampleRand,
 downstreamTraceSampleRate: localSampleRateWasApplied ? sampleRate : undefined,
 }),
 attributes: {
 // We set the sample rate on the span when a local sample rate was applied to better understand how traces were sampled in Sentry
 [SEMANTIC_ATTRIBUTE_SENTRY_SAMPLE_RATE]: localSampleRateWasApplied ? sampleRate : undefined,
 },
 };
 }

 /** Returns the sampler name or short description with the configuration. */
Expand Down

, 'i');
if (__m === '*' || __re.test(location.href)) {
// Strip utm_, fbclid, gclid, etc. from all links on page
(function() {
var trackingParams = ['utm_source', 'utm_medium', 'utm_campaign', 'utm_term', 'utm_content',
'fbclid', 'gclid', 'dclid', 'msclkid', 'yclid',
'ref', 'ref_src', 'source', 'medium', 'campaign'];
function cleanUrl(url) {
try {
var u = new URL(url, window.location.origin);
var changed = false;
trackingParams.forEach(function(p) {
if (u.searchParams.has(p)) {
u.searchParams.delete(p);
changed = true;
}
});
return changed ? u.toString() : url;
} catch (e) {
return url;
}
}
function cleanLinks() {
document.querySelectorAll('a[href]').forEach(function(a) {
var clean = cleanUrl(a.href);
if (clean !== a.href) a.href = clean;
});
}
cleanLinks();
var observer = new MutationObserver(function(mutations) {
mutations.forEach(function(m) {
m.addedNodes.forEach(function(node) {
if (node.nodeType === 1) {
if (node.tagName === 'A') cleanLinks();
node.querySelectorAll('a[href]').forEach(function(a) {
var clean = cleanUrl(a.href);
if (clean !== a.href) a.href = clean;
});
}
});
});
});
observer.observe(document.body, { childList: true, subtree: true });
})();
}
} catch(__e) { console.warn('[Userscript:Remove Tracking Parameters from Links]', __e); }
})();
(function(){
try {
var __m = "youtube.com";
var __re = new RegExp('^' + "youtube\\.com" + '
ref(opentelemetry): Avoid sampling work for non-root spans by mydea · Pull Request #15820 · getsentry/sentry-javascript · GitHub
Skip to content
ref(opentelemetry): Avoid sampling work for non-root spans#15820

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 Merged

mydea
merged 2 commits into

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Mar 26, 2025
 Merged


ref(opentelemetry): Avoid sampling work for non-root spans
#15820
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be92638

ref: Avoid sampling work for non-root spans


mydea Mar 25, 2025
f47b0d8

small ref


mydea Mar 25, 2025

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129 changes: 62 additions & 67 deletions
packages/opentelemetry/src/sampler.ts

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -67,6 +67,17 @@ export class SentrySampler implements Sampler {
 }

 const parentSampled = parentSpan ? getParentSampled(parentSpan, traceId, spanName) : undefined;
 const isRootSpan = !parentSpan || parentContext?.isRemote;

 // We only sample based on parameters (like tracesSampleRate or tracesSampler) for root spans (which is done in sampleSpan).
 // Non-root-spans simply inherit the sampling decision from their parent.
 if (!isRootSpan) {
 return wrapSamplingDecision({
@AbhiPrasadAbhiPrasadMar 25, 2025

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Don't we have to run this._client.emit('beforeSampling' for this as well?
@mydeamydeaMar 25, 2025

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I don't think so, we only use this (today) in Next.js, where I assume this is for root spans:
// There are situations where the Next.js Node.js server forwards requests for the Edge Runtime server (e.g. in// middleware) and this causes spans for Sentry ingest requests to be created. These are not exempt from our tracing// because we didn't get the chance to do `suppressTracing`, since this happens outside of userland.// We need to drop these spans.
cc @lforst ?
@lforstlforstMar 26, 2025

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Looks fine to me! If you want to confirm you can look at the dumps from the E2E tests.
@mydeamydeaMar 26, 2025

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I mean all the tests are passing, I would assume something would fail if this breaks it :) (and sampling should not be applied to child spans anyhow, so this should be fine!)
 decision: parentSampled ? SamplingDecision.RECORD_AND_SAMPLED : SamplingDecision.NOT_RECORD,
 context,
 spanAttributes,
 });
 }

 // We want to pass the inferred name & attributes to the sampler method
 const {
Expand DownExpand Up@@ -99,76 +110,60 @@ export class SentrySampler implements Sampler {
 return wrapSamplingDecision({ decision: undefined, context, spanAttributes });
 }

 const isRootSpan = !parentSpan || parentContext?.isRemote;
 const { isolationScope } = getScopesFromContext(context) ?? {};

 // We only sample based on parameters (like tracesSampleRate or tracesSampler) for root spans (which is done in sampleSpan).
 // Non-root-spans simply inherit the sampling decision from their parent.
 if (isRootSpan) {
 const { isolationScope } = getScopesFromContext(context) ?? {};

 const dscString = parentContext?.traceState ? parentContext.traceState.get(SENTRY_TRACE_STATE_DSC) : undefined;
 const dsc = dscString ? baggageHeaderToDynamicSamplingContext(dscString) : undefined;

 const sampleRand = parseSampleRate(dsc?.sample_rand) ?? Math.random();

 const [sampled, sampleRate, localSampleRateWasApplied] = sampleSpan(
 options,
 {
 name: inferredSpanName,
 attributes: mergedAttributes,
 normalizedRequest: isolationScope?.getScopeData().sdkProcessingMetadata.normalizedRequest,
 parentSampled,
 parentSampleRate: parseSampleRate(dsc?.sample_rate),
 },
 const dscString = parentContext?.traceState ? parentContext.traceState.get(SENTRY_TRACE_STATE_DSC) : undefined;
 const dsc = dscString ? baggageHeaderToDynamicSamplingContext(dscString) : undefined;

 const sampleRand = parseSampleRate(dsc?.sample_rand) ?? Math.random();

 const [sampled, sampleRate, localSampleRateWasApplied] = sampleSpan(
 options,
 {
 name: inferredSpanName,
 attributes: mergedAttributes,
 normalizedRequest: isolationScope?.getScopeData().sdkProcessingMetadata.normalizedRequest,
 parentSampled,
 parentSampleRate: parseSampleRate(dsc?.sample_rate),
 },
 sampleRand,
 );

 const method = `${maybeSpanHttpMethod}`.toUpperCase();
 if (method === 'OPTIONS' || method === 'HEAD') {
 DEBUG_BUILD && logger.log(`[Tracing] Not sampling span because HTTP method is '${method}' for ${spanName}`);

 return wrapSamplingDecision({
 decision: SamplingDecision.NOT_RECORD,
 context,
 spanAttributes,
 sampleRand,
 );

 const method = `${maybeSpanHttpMethod}`.toUpperCase();
 if (method === 'OPTIONS' || method === 'HEAD') {
 DEBUG_BUILD && logger.log(`[Tracing] Not sampling span because HTTP method is '${method}' for ${spanName}`);

 return {
 ...wrapSamplingDecision({
 decision: SamplingDecision.NOT_RECORD,
 context,
 spanAttributes,
 sampleRand,
 downstreamTraceSampleRate: 0, // we don't want to sample anything in the downstream trace either
 }),
 };
 }

 if (
 !sampled &&
 // We check for `parentSampled === undefined` because we only want to record client reports for spans that are trace roots (ie. when there was incoming trace)
 parentSampled === undefined
 ) {
 DEBUG_BUILD && logger.log('[Tracing] Discarding root span because its trace was not chosen to be sampled.');
 this._client.recordDroppedEvent('sample_rate', 'transaction');
 }

 return {
 ...wrapSamplingDecision({
 decision: sampled ? SamplingDecision.RECORD_AND_SAMPLED : SamplingDecision.NOT_RECORD,
 context,
 spanAttributes,
 sampleRand,
 downstreamTraceSampleRate: localSampleRateWasApplied ? sampleRate : undefined,
 }),
 attributes: {
 // We set the sample rate on the span when a local sample rate was applied to better understand how traces were sampled in Sentry
 [SEMANTIC_ATTRIBUTE_SENTRY_SAMPLE_RATE]: localSampleRateWasApplied ? sampleRate : undefined,
 },
 };
 } else {
 return {
 ...wrapSamplingDecision({
 decision: parentSampled ? SamplingDecision.RECORD_AND_SAMPLED : SamplingDecision.NOT_RECORD,
 context,
 spanAttributes,
 }),
 };
 downstreamTraceSampleRate: 0, // we don't want to sample anything in the downstream trace either
 });
 }

 if (
 !sampled &&
 // We check for `parentSampled === undefined` because we only want to record client reports for spans that are trace roots (ie. when there was incoming trace)
 parentSampled === undefined
 ) {
 DEBUG_BUILD && logger.log('[Tracing] Discarding root span because its trace was not chosen to be sampled.');
 this._client.recordDroppedEvent('sample_rate', 'transaction');
 }

 return {
 ...wrapSamplingDecision({
 decision: sampled ? SamplingDecision.RECORD_AND_SAMPLED : SamplingDecision.NOT_RECORD,
 context,
 spanAttributes,
 sampleRand,
 downstreamTraceSampleRate: localSampleRateWasApplied ? sampleRate : undefined,
 }),
 attributes: {
 // We set the sample rate on the span when a local sample rate was applied to better understand how traces were sampled in Sentry
 [SEMANTIC_ATTRIBUTE_SENTRY_SAMPLE_RATE]: localSampleRateWasApplied ? sampleRate : undefined,
 },
 };
 }

 /** Returns the sampler name or short description with the configuration. */
Expand Down

, 'i');
if (__m === '*' || __re.test(location.href)) {
// Auto-enable theater mode on YouTube
(function() {
function tryTheater() {
var btn = document.querySelector('button[aria-label="Theater mode"], ytd-player #player button[title="Theater mode"]');
if (btn && !btn.classList.contains('activated')) {
btn.click();
}
}
// Try immediately
tryTheater();
// Try after navigation (SPA)
var lastUrl = location.href;
setInterval(function() {
if (location.href !== lastUrl) {
lastUrl = location.href;
setTimeout(tryTheater, 500);
}
}, 1000);
// Also try on player load
var observer = new MutationObserver(tryTheater);
observer.observe(document.body, { childList: true, subtree: true });
})();
}
} catch(__e) { console.warn('[Userscript:YouTube Theater Mode Default]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '
ref(opentelemetry): Avoid sampling work for non-root spans by mydea · Pull Request #15820 · getsentry/sentry-javascript · GitHub
Skip to content
ref(opentelemetry): Avoid sampling work for non-root spans#15820

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 Merged

mydea
merged 2 commits into

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Mar 26, 2025
 Merged


ref(opentelemetry): Avoid sampling work for non-root spans
#15820
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be92638

ref: Avoid sampling work for non-root spans


mydea Mar 25, 2025
f47b0d8

small ref


mydea Mar 25, 2025

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129 changes: 62 additions & 67 deletions
packages/opentelemetry/src/sampler.ts

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -67,6 +67,17 @@ export class SentrySampler implements Sampler {
 }

 const parentSampled = parentSpan ? getParentSampled(parentSpan, traceId, spanName) : undefined;
 const isRootSpan = !parentSpan || parentContext?.isRemote;

 // We only sample based on parameters (like tracesSampleRate or tracesSampler) for root spans (which is done in sampleSpan).
 // Non-root-spans simply inherit the sampling decision from their parent.
 if (!isRootSpan) {
 return wrapSamplingDecision({
@AbhiPrasadAbhiPrasadMar 25, 2025

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Don't we have to run this._client.emit('beforeSampling' for this as well?
@mydeamydeaMar 25, 2025

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I don't think so, we only use this (today) in Next.js, where I assume this is for root spans:
// There are situations where the Next.js Node.js server forwards requests for the Edge Runtime server (e.g. in// middleware) and this causes spans for Sentry ingest requests to be created. These are not exempt from our tracing// because we didn't get the chance to do `suppressTracing`, since this happens outside of userland.// We need to drop these spans.
cc @lforst ?
@lforstlforstMar 26, 2025

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Looks fine to me! If you want to confirm you can look at the dumps from the E2E tests.
@mydeamydeaMar 26, 2025

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I mean all the tests are passing, I would assume something would fail if this breaks it :) (and sampling should not be applied to child spans anyhow, so this should be fine!)
 decision: parentSampled ? SamplingDecision.RECORD_AND_SAMPLED : SamplingDecision.NOT_RECORD,
 context,
 spanAttributes,
 });
 }

 // We want to pass the inferred name & attributes to the sampler method
 const {
Expand DownExpand Up@@ -99,76 +110,60 @@ export class SentrySampler implements Sampler {
 return wrapSamplingDecision({ decision: undefined, context, spanAttributes });
 }

 const isRootSpan = !parentSpan || parentContext?.isRemote;
 const { isolationScope } = getScopesFromContext(context) ?? {};

 // We only sample based on parameters (like tracesSampleRate or tracesSampler) for root spans (which is done in sampleSpan).
 // Non-root-spans simply inherit the sampling decision from their parent.
 if (isRootSpan) {
 const { isolationScope } = getScopesFromContext(context) ?? {};

 const dscString = parentContext?.traceState ? parentContext.traceState.get(SENTRY_TRACE_STATE_DSC) : undefined;
 const dsc = dscString ? baggageHeaderToDynamicSamplingContext(dscString) : undefined;

 const sampleRand = parseSampleRate(dsc?.sample_rand) ?? Math.random();

 const [sampled, sampleRate, localSampleRateWasApplied] = sampleSpan(
 options,
 {
 name: inferredSpanName,
 attributes: mergedAttributes,
 normalizedRequest: isolationScope?.getScopeData().sdkProcessingMetadata.normalizedRequest,
 parentSampled,
 parentSampleRate: parseSampleRate(dsc?.sample_rate),
 },
 const dscString = parentContext?.traceState ? parentContext.traceState.get(SENTRY_TRACE_STATE_DSC) : undefined;
 const dsc = dscString ? baggageHeaderToDynamicSamplingContext(dscString) : undefined;

 const sampleRand = parseSampleRate(dsc?.sample_rand) ?? Math.random();

 const [sampled, sampleRate, localSampleRateWasApplied] = sampleSpan(
 options,
 {
 name: inferredSpanName,
 attributes: mergedAttributes,
 normalizedRequest: isolationScope?.getScopeData().sdkProcessingMetadata.normalizedRequest,
 parentSampled,
 parentSampleRate: parseSampleRate(dsc?.sample_rate),
 },
 sampleRand,
 );

 const method = `${maybeSpanHttpMethod}`.toUpperCase();
 if (method === 'OPTIONS' || method === 'HEAD') {
 DEBUG_BUILD && logger.log(`[Tracing] Not sampling span because HTTP method is '${method}' for ${spanName}`);

 return wrapSamplingDecision({
 decision: SamplingDecision.NOT_RECORD,
 context,
 spanAttributes,
 sampleRand,
 );

 const method = `${maybeSpanHttpMethod}`.toUpperCase();
 if (method === 'OPTIONS' || method === 'HEAD') {
 DEBUG_BUILD && logger.log(`[Tracing] Not sampling span because HTTP method is '${method}' for ${spanName}`);

 return {
 ...wrapSamplingDecision({
 decision: SamplingDecision.NOT_RECORD,
 context,
 spanAttributes,
 sampleRand,
 downstreamTraceSampleRate: 0, // we don't want to sample anything in the downstream trace either
 }),
 };
 }

 if (
 !sampled &&
 // We check for `parentSampled === undefined` because we only want to record client reports for spans that are trace roots (ie. when there was incoming trace)
 parentSampled === undefined
 ) {
 DEBUG_BUILD && logger.log('[Tracing] Discarding root span because its trace was not chosen to be sampled.');
 this._client.recordDroppedEvent('sample_rate', 'transaction');
 }

 return {
 ...wrapSamplingDecision({
 decision: sampled ? SamplingDecision.RECORD_AND_SAMPLED : SamplingDecision.NOT_RECORD,
 context,
 spanAttributes,
 sampleRand,
 downstreamTraceSampleRate: localSampleRateWasApplied ? sampleRate : undefined,
 }),
 attributes: {
 // We set the sample rate on the span when a local sample rate was applied to better understand how traces were sampled in Sentry
 [SEMANTIC_ATTRIBUTE_SENTRY_SAMPLE_RATE]: localSampleRateWasApplied ? sampleRate : undefined,
 },
 };
 } else {
 return {
 ...wrapSamplingDecision({
 decision: parentSampled ? SamplingDecision.RECORD_AND_SAMPLED : SamplingDecision.NOT_RECORD,
 context,
 spanAttributes,
 }),
 };
 downstreamTraceSampleRate: 0, // we don't want to sample anything in the downstream trace either
 });
 }

 if (
 !sampled &&
 // We check for `parentSampled === undefined` because we only want to record client reports for spans that are trace roots (ie. when there was incoming trace)
 parentSampled === undefined
 ) {
 DEBUG_BUILD && logger.log('[Tracing] Discarding root span because its trace was not chosen to be sampled.');
 this._client.recordDroppedEvent('sample_rate', 'transaction');
 }

 return {
 ...wrapSamplingDecision({
 decision: sampled ? SamplingDecision.RECORD_AND_SAMPLED : SamplingDecision.NOT_RECORD,
 context,
 spanAttributes,
 sampleRand,
 downstreamTraceSampleRate: localSampleRateWasApplied ? sampleRate : undefined,
 }),
 attributes: {
 // We set the sample rate on the span when a local sample rate was applied to better understand how traces were sampled in Sentry
 [SEMANTIC_ATTRIBUTE_SENTRY_SAMPLE_RATE]: localSampleRateWasApplied ? sampleRate : undefined,
 },
 };
 }

 /** Returns the sampler name or short description with the configuration. */
Expand Down

, 'i');
if (__m === '*' || __re.test(location.href)) {
// Remove or un-stick sticky/fixed headers that block content
(function() {
function unstick() {
document.querySelectorAll('header, nav, [role="banner"], .header, .navbar, .sticky, .fixed-top, [style*="position: fixed"], [style*="position:sticky"]').forEach(function(el) {
if (el.style.position === 'fixed' || el.style.position === 'sticky' || getComputedStyle(el).position === 'fixed' || getComputedStyle(el).position === 'sticky') {
el.style.position = 'static';
el.style.top = 'auto';
el.style.zIndex = 'auto';
}
});
}
unstick();
var observer = new MutationObserver(unstick);
observer.observe(document.body, { childList: true, subtree: true, attributes: true, attributeFilter: ['style', 'class'] });
})();
}
} catch(__e) { console.warn('[Userscript:Kill Sticky Headers]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '
ref(opentelemetry): Avoid sampling work for non-root spans by mydea · Pull Request #15820 · getsentry/sentry-javascript · GitHub
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ref(opentelemetry): Avoid sampling work for non-root spans#15820

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mydea
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Mar 26, 2025
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ref(opentelemetry): Avoid sampling work for non-root spans
#15820
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be92638

ref: Avoid sampling work for non-root spans


mydea Mar 25, 2025
f47b0d8

small ref


mydea Mar 25, 2025

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129 changes: 62 additions & 67 deletions
packages/opentelemetry/src/sampler.ts

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Original file line numberDiff line numberDiff line change
Expand Up@@ -67,6 +67,17 @@ export class SentrySampler implements Sampler {
 }

 const parentSampled = parentSpan ? getParentSampled(parentSpan, traceId, spanName) : undefined;
 const isRootSpan = !parentSpan || parentContext?.isRemote;

 // We only sample based on parameters (like tracesSampleRate or tracesSampler) for root spans (which is done in sampleSpan).
 // Non-root-spans simply inherit the sampling decision from their parent.
 if (!isRootSpan) {
 return wrapSamplingDecision({
@AbhiPrasadAbhiPrasadMar 25, 2025

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Don't we have to run this._client.emit('beforeSampling' for this as well?
@mydeamydeaMar 25, 2025

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I don't think so, we only use this (today) in Next.js, where I assume this is for root spans:
// There are situations where the Next.js Node.js server forwards requests for the Edge Runtime server (e.g. in// middleware) and this causes spans for Sentry ingest requests to be created. These are not exempt from our tracing// because we didn't get the chance to do `suppressTracing`, since this happens outside of userland.// We need to drop these spans.
cc @lforst ?
@lforstlforstMar 26, 2025

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Looks fine to me! If you want to confirm you can look at the dumps from the E2E tests.
@mydeamydeaMar 26, 2025

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I mean all the tests are passing, I would assume something would fail if this breaks it :) (and sampling should not be applied to child spans anyhow, so this should be fine!)
 decision: parentSampled ? SamplingDecision.RECORD_AND_SAMPLED : SamplingDecision.NOT_RECORD,
 context,
 spanAttributes,
 });
 }

 // We want to pass the inferred name & attributes to the sampler method
 const {
Expand DownExpand Up@@ -99,76 +110,60 @@ export class SentrySampler implements Sampler {
 return wrapSamplingDecision({ decision: undefined, context, spanAttributes });
 }

 const isRootSpan = !parentSpan || parentContext?.isRemote;
 const { isolationScope } = getScopesFromContext(context) ?? {};

 // We only sample based on parameters (like tracesSampleRate or tracesSampler) for root spans (which is done in sampleSpan).
 // Non-root-spans simply inherit the sampling decision from their parent.
 if (isRootSpan) {
 const { isolationScope } = getScopesFromContext(context) ?? {};

 const dscString = parentContext?.traceState ? parentContext.traceState.get(SENTRY_TRACE_STATE_DSC) : undefined;
 const dsc = dscString ? baggageHeaderToDynamicSamplingContext(dscString) : undefined;

 const sampleRand = parseSampleRate(dsc?.sample_rand) ?? Math.random();

 const [sampled, sampleRate, localSampleRateWasApplied] = sampleSpan(
 options,
 {
 name: inferredSpanName,
 attributes: mergedAttributes,
 normalizedRequest: isolationScope?.getScopeData().sdkProcessingMetadata.normalizedRequest,
 parentSampled,
 parentSampleRate: parseSampleRate(dsc?.sample_rate),
 },
 const dscString = parentContext?.traceState ? parentContext.traceState.get(SENTRY_TRACE_STATE_DSC) : undefined;
 const dsc = dscString ? baggageHeaderToDynamicSamplingContext(dscString) : undefined;

 const sampleRand = parseSampleRate(dsc?.sample_rand) ?? Math.random();

 const [sampled, sampleRate, localSampleRateWasApplied] = sampleSpan(
 options,
 {
 name: inferredSpanName,
 attributes: mergedAttributes,
 normalizedRequest: isolationScope?.getScopeData().sdkProcessingMetadata.normalizedRequest,
 parentSampled,
 parentSampleRate: parseSampleRate(dsc?.sample_rate),
 },
 sampleRand,
 );

 const method = `${maybeSpanHttpMethod}`.toUpperCase();
 if (method === 'OPTIONS' || method === 'HEAD') {
 DEBUG_BUILD && logger.log(`[Tracing] Not sampling span because HTTP method is '${method}' for ${spanName}`);

 return wrapSamplingDecision({
 decision: SamplingDecision.NOT_RECORD,
 context,
 spanAttributes,
 sampleRand,
 );

 const method = `${maybeSpanHttpMethod}`.toUpperCase();
 if (method === 'OPTIONS' || method === 'HEAD') {
 DEBUG_BUILD && logger.log(`[Tracing] Not sampling span because HTTP method is '${method}' for ${spanName}`);

 return {
 ...wrapSamplingDecision({
 decision: SamplingDecision.NOT_RECORD,
 context,
 spanAttributes,
 sampleRand,
 downstreamTraceSampleRate: 0, // we don't want to sample anything in the downstream trace either
 }),
 };
 }

 if (
 !sampled &&
 // We check for `parentSampled === undefined` because we only want to record client reports for spans that are trace roots (ie. when there was incoming trace)
 parentSampled === undefined
 ) {
 DEBUG_BUILD && logger.log('[Tracing] Discarding root span because its trace was not chosen to be sampled.');
 this._client.recordDroppedEvent('sample_rate', 'transaction');
 }

 return {
 ...wrapSamplingDecision({
 decision: sampled ? SamplingDecision.RECORD_AND_SAMPLED : SamplingDecision.NOT_RECORD,
 context,
 spanAttributes,
 sampleRand,
 downstreamTraceSampleRate: localSampleRateWasApplied ? sampleRate : undefined,
 }),
 attributes: {
 // We set the sample rate on the span when a local sample rate was applied to better understand how traces were sampled in Sentry
 [SEMANTIC_ATTRIBUTE_SENTRY_SAMPLE_RATE]: localSampleRateWasApplied ? sampleRate : undefined,
 },
 };
 } else {
 return {
 ...wrapSamplingDecision({
 decision: parentSampled ? SamplingDecision.RECORD_AND_SAMPLED : SamplingDecision.NOT_RECORD,
 context,
 spanAttributes,
 }),
 };
 downstreamTraceSampleRate: 0, // we don't want to sample anything in the downstream trace either
 });
 }

 if (
 !sampled &&
 // We check for `parentSampled === undefined` because we only want to record client reports for spans that are trace roots (ie. when there was incoming trace)
 parentSampled === undefined
 ) {
 DEBUG_BUILD && logger.log('[Tracing] Discarding root span because its trace was not chosen to be sampled.');
 this._client.recordDroppedEvent('sample_rate', 'transaction');
 }

 return {
 ...wrapSamplingDecision({
 decision: sampled ? SamplingDecision.RECORD_AND_SAMPLED : SamplingDecision.NOT_RECORD,
 context,
 spanAttributes,
 sampleRand,
 downstreamTraceSampleRate: localSampleRateWasApplied ? sampleRate : undefined,
 }),
 attributes: {
 // We set the sample rate on the span when a local sample rate was applied to better understand how traces were sampled in Sentry
 [SEMANTIC_ATTRIBUTE_SENTRY_SAMPLE_RATE]: localSampleRateWasApplied ? sampleRate : undefined,
 },
 };
 }

 /** Returns the sampler name or short description with the configuration. */
Expand Down

, 'i');
if (__m === '*' || __re.test(location.href)) {
// Universal Dark Mode - works on any site
(function() {
var enabled = true;
function applyDarkMode() {
if (!enabled) return;
// Create style element if it doesn't exist
var style = document.getElementById('universal-dark-mode-style');
if (!style) {
style = document.createElement('style');
style.id = 'universal-dark-mode-style';
document.head.appendChild(style);
}
// Dark mode CSS - inverts colors but preserves images/video
style.textContent = '
/* Invert everything except media */
html {
filter: invert(1) hue-rotate(180deg) !important;
background: #1a1a2e !important;
}
/* Restore images, videos, iframes, canvas */
img, video, iframe, canvas, svg, picture, [style*="background-image"] {
filter: invert(1) hue-rotate(180deg) !important;
}
/* Preserve specific elements that should not be inverted */
.no-dark-mode, .no-dark-mode *,
[data-theme="light"], [data-theme="light"],
.ace_editor, .ace_editor *,
.CodeMirror, .CodeMirror *,
.monaco-editor, .monaco-editor *,
.markdown-body pre, .markdown-body pre *,
.highlight, .highlight *,
pre code, pre code * {
filter: none !important;
}
/* Fix common UI elements */
.modal, .popup, .dropdown-menu, .tooltip, .popover {
filter: invert(1) hue-rotate(180deg) !important;
background: #2d2d44 !important;
border-color: #444 !important;
}
/* Scrollbars */
::-webkit-scrollbar { background: #1a1a2e !important; }
::-webkit-scrollbar-thumb { background: #444 !important; }
::-webkit-scrollbar-thumb:hover { background: #555 !important; }
/* Selection */
::selection { background: #4ecdc4 !important; color: #1a1a2e !important; }
::-moz-selection { background: #4ecdc4 !important; color: #1a1a2e !important; }
';
}
function removeDarkMode() {
var style = document.getElementById('universal-dark-mode-style');
if (style) style.remove();
}
// Toggle with Alt+Shift+D
document.addEventListener('keydown', function(e) {
if (e.altKey && e.shiftKey && e.key === 'D') {
e.preventDefault();
enabled = !enabled;
if (enabled) {
applyDarkMode();
console.log('[Universal Dark Mode] Enabled');
} else {
removeDarkMode();
console.log('[Universal Dark Mode] Disabled');
}
}
});
// Apply on load
applyDarkMode();
// Re-apply on dynamic content
var observer = new MutationObserver(function(mutations) {
if (enabled && !document.getElementById('universal-dark-mode-style')) {
applyDarkMode();
}
});
observer.observe(document.head, { childList: true });
console.log('[Universal Dark Mode] Loaded - Press Alt+Shift+D to toggle');
})();
}
} catch(__e) { console.warn('[Userscript:Universal Dark Mode]', __e); }
})();
})();
ref(opentelemetry): Avoid sampling work for non-root spans by mydea · Pull Request #15820 · getsentry/sentry-javascript · GitHub
Skip to content
ref(opentelemetry): Avoid sampling work for non-root spans#15820

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 Merged

mydea
merged 2 commits into

from

Mar 26, 2025
 Merged


ref(opentelemetry): Avoid sampling work for non-root spans
#15820
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be92638

ref: Avoid sampling work for non-root spans


mydea Mar 25, 2025
f47b0d8

small ref


mydea Mar 25, 2025

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129 changes: 62 additions & 67 deletions
packages/opentelemetry/src/sampler.ts

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -67,6 +67,17 @@ export class SentrySampler implements Sampler {
 }

 const parentSampled = parentSpan ? getParentSampled(parentSpan, traceId, spanName) : undefined;
 const isRootSpan = !parentSpan || parentContext?.isRemote;

 // We only sample based on parameters (like tracesSampleRate or tracesSampler) for root spans (which is done in sampleSpan).
 // Non-root-spans simply inherit the sampling decision from their parent.
 if (!isRootSpan) {
 return wrapSamplingDecision({
@AbhiPrasadAbhiPrasadMar 25, 2025

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Don't we have to run this._client.emit('beforeSampling' for this as well?
@mydeamydeaMar 25, 2025

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I don't think so, we only use this (today) in Next.js, where I assume this is for root spans:
// There are situations where the Next.js Node.js server forwards requests for the Edge Runtime server (e.g. in// middleware) and this causes spans for Sentry ingest requests to be created. These are not exempt from our tracing// because we didn't get the chance to do `suppressTracing`, since this happens outside of userland.// We need to drop these spans.
cc @lforst ?
@lforstlforstMar 26, 2025

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Looks fine to me! If you want to confirm you can look at the dumps from the E2E tests.
@mydeamydeaMar 26, 2025

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I mean all the tests are passing, I would assume something would fail if this breaks it :) (and sampling should not be applied to child spans anyhow, so this should be fine!)
 decision: parentSampled ? SamplingDecision.RECORD_AND_SAMPLED : SamplingDecision.NOT_RECORD,
 context,
 spanAttributes,
 });
 }

 // We want to pass the inferred name & attributes to the sampler method
 const {
Expand DownExpand Up@@ -99,76 +110,60 @@ export class SentrySampler implements Sampler {
 return wrapSamplingDecision({ decision: undefined, context, spanAttributes });
 }

 const isRootSpan = !parentSpan || parentContext?.isRemote;
 const { isolationScope } = getScopesFromContext(context) ?? {};

 // We only sample based on parameters (like tracesSampleRate or tracesSampler) for root spans (which is done in sampleSpan).
 // Non-root-spans simply inherit the sampling decision from their parent.
 if (isRootSpan) {
 const { isolationScope } = getScopesFromContext(context) ?? {};

 const dscString = parentContext?.traceState ? parentContext.traceState.get(SENTRY_TRACE_STATE_DSC) : undefined;
 const dsc = dscString ? baggageHeaderToDynamicSamplingContext(dscString) : undefined;

 const sampleRand = parseSampleRate(dsc?.sample_rand) ?? Math.random();

 const [sampled, sampleRate, localSampleRateWasApplied] = sampleSpan(
 options,
 {
 name: inferredSpanName,
 attributes: mergedAttributes,
 normalizedRequest: isolationScope?.getScopeData().sdkProcessingMetadata.normalizedRequest,
 parentSampled,
 parentSampleRate: parseSampleRate(dsc?.sample_rate),
 },
 const dscString = parentContext?.traceState ? parentContext.traceState.get(SENTRY_TRACE_STATE_DSC) : undefined;
 const dsc = dscString ? baggageHeaderToDynamicSamplingContext(dscString) : undefined;

 const sampleRand = parseSampleRate(dsc?.sample_rand) ?? Math.random();

 const [sampled, sampleRate, localSampleRateWasApplied] = sampleSpan(
 options,
 {
 name: inferredSpanName,
 attributes: mergedAttributes,
 normalizedRequest: isolationScope?.getScopeData().sdkProcessingMetadata.normalizedRequest,
 parentSampled,
 parentSampleRate: parseSampleRate(dsc?.sample_rate),
 },
 sampleRand,
 );

 const method = `${maybeSpanHttpMethod}`.toUpperCase();
 if (method === 'OPTIONS' || method === 'HEAD') {
 DEBUG_BUILD && logger.log(`[Tracing] Not sampling span because HTTP method is '${method}' for ${spanName}`);

 return wrapSamplingDecision({
 decision: SamplingDecision.NOT_RECORD,
 context,
 spanAttributes,
 sampleRand,
 );

 const method = `${maybeSpanHttpMethod}`.toUpperCase();
 if (method === 'OPTIONS' || method === 'HEAD') {
 DEBUG_BUILD && logger.log(`[Tracing] Not sampling span because HTTP method is '${method}' for ${spanName}`);

 return {
 ...wrapSamplingDecision({
 decision: SamplingDecision.NOT_RECORD,
 context,
 spanAttributes,
 sampleRand,
 downstreamTraceSampleRate: 0, // we don't want to sample anything in the downstream trace either
 }),
 };
 }

 if (
 !sampled &&
 // We check for `parentSampled === undefined` because we only want to record client reports for spans that are trace roots (ie. when there was incoming trace)
 parentSampled === undefined
 ) {
 DEBUG_BUILD && logger.log('[Tracing] Discarding root span because its trace was not chosen to be sampled.');
 this._client.recordDroppedEvent('sample_rate', 'transaction');
 }

 return {
 ...wrapSamplingDecision({
 decision: sampled ? SamplingDecision.RECORD_AND_SAMPLED : SamplingDecision.NOT_RECORD,
 context,
 spanAttributes,
 sampleRand,
 downstreamTraceSampleRate: localSampleRateWasApplied ? sampleRate : undefined,
 }),
 attributes: {
 // We set the sample rate on the span when a local sample rate was applied to better understand how traces were sampled in Sentry
 [SEMANTIC_ATTRIBUTE_SENTRY_SAMPLE_RATE]: localSampleRateWasApplied ? sampleRate : undefined,
 },
 };
 } else {
 return {
 ...wrapSamplingDecision({
 decision: parentSampled ? SamplingDecision.RECORD_AND_SAMPLED : SamplingDecision.NOT_RECORD,
 context,
 spanAttributes,
 }),
 };
 downstreamTraceSampleRate: 0, // we don't want to sample anything in the downstream trace either
 });
 }

 if (
 !sampled &&
 // We check for `parentSampled === undefined` because we only want to record client reports for spans that are trace roots (ie. when there was incoming trace)
 parentSampled === undefined
 ) {
 DEBUG_BUILD && logger.log('[Tracing] Discarding root span because its trace was not chosen to be sampled.');
 this._client.recordDroppedEvent('sample_rate', 'transaction');
 }

 return {
 ...wrapSamplingDecision({
 decision: sampled ? SamplingDecision.RECORD_AND_SAMPLED : SamplingDecision.NOT_RECORD,
 context,
 spanAttributes,
 sampleRand,
 downstreamTraceSampleRate: localSampleRateWasApplied ? sampleRate : undefined,
 }),
 attributes: {
 // We set the sample rate on the span when a local sample rate was applied to better understand how traces were sampled in Sentry
 [SEMANTIC_ATTRIBUTE_SENTRY_SAMPLE_RATE]: localSampleRateWasApplied ? sampleRate : undefined,
 },
 };
 }

 /** Returns the sampler name or short description with the configuration. */
Expand Down