Can not add sentry-trace header to every fetch

[batamar]

• [ x] Review the documentation: https://docs.sentry.io/
• [x ] Search for existing issues: https://github.com/getsentry/sentry-javascript/issues
• [x ] Use the latest release: https://github.com/getsentry/sentry-javascript/releases
• Provide a link to the affected event from your Sentry account

Package + Version

• [5.29.2 ] @sentry/browser
• [ 5.29.2] @sentry/node
• raven-js
• raven-node (raven for node)
• other:

Description

For this request this added

But for next several request it is not adding

[t-h-man]

Can you share the SDK init?

[kamilogorek]

sentry-trace header is only attached, if there is an active transaction happening. If Sentry.getScope().getSpan() returns null (which is equivalent to transaction not being active), this operation is skipped.
Your first request has the header because initial page load and page navigations are creating transactions, which finish once the operation completes.

Responsible code:

sentry-javascript/packages/node/src/integrations/http.ts

Lines 109 to 122 in e7e9199

	const scope = getCurrentHub().getScope();
	if (scope && tracingEnabled) {
	parentSpan = scope.getSpan();
	if (parentSpan) {
	span = parentSpan.startChild({
	description: `${requestOptions.method || 'GET'} ${requestUrl}`,
	op: 'request',
	});
	const sentryTraceHeader = span.toTraceparent();
	logger.log(`[Tracing] Adding sentry-trace header to outgoing request: ${sentryTraceHeader}`);
	requestOptions.headers = { ...requestOptions.headers, 'sentry-trace': sentryTraceHeader };
	}
	}

sentry-javascript/packages/tracing/src/browser/request.ts

Lines 173 to 208 in e7e9199

	const activeTransaction = getActiveTransaction();
	if (activeTransaction) {
	const span = activeTransaction.startChild({
	data: {
	...handlerData.fetchData,
	type: 'fetch',
	},
	description: `${handlerData.fetchData.method} ${handlerData.fetchData.url}`,
	op: 'http',
	});
	handlerData.fetchData.__span = span.spanId;
	spans[span.spanId] = span;
	const request = (handlerData.args[0] = handlerData.args[0] as string | Request);
	// eslint-disable-next-line @typescript-eslint/no-explicit-any
	const options = (handlerData.args[1] = (handlerData.args[1] as { [key: string]: any }) || {});
	let headers = options.headers;
	if (isInstanceOf(request, Request)) {
	headers = (request as Request).headers;
	}
	if (headers) {
	// eslint-disable-next-line @typescript-eslint/no-unsafe-member-access
	if (typeof headers.append === 'function') {
	// eslint-disable-next-line @typescript-eslint/no-unsafe-member-access
	headers.append('sentry-trace', span.toTraceparent());
	} else if (Array.isArray(headers)) {
	headers = [...headers, ['sentry-trace', span.toTraceparent()]];
	} else {
	headers = { ...headers, 'sentry-trace': span.toTraceparent() };
	}
	} else {
	headers = { 'sentry-trace': span.toTraceparent() };
	}
	options.headers = headers;
	}

[kamilogorek]

Closing the issue as a part of large repository cleanup, due to it being inactive and/or outdated. There's a large chance that this issue has been solved since.
Please do not hesitate to ping me if it is still relevant, and I will happily reopen and work on it.
Cheers!

[laygir]

Hey there,

I've been trying the tracing/performance features of Sentry recently, and I noticed this behaviour on my end.
Not every http requests have the sentry-trace header.

I have been in touch with Sentry support but it is taking too long, so I thought I would approach here as well.

Sentry support wrote me the following statements in two different emails:

• "if a transaction doesn't exist, no sentry-trace header will be attached to a request."
• "For the front-end side, the automatic instrumentation should create transaction to every XHR request (as long as the sampling is 100%)."

Above statements feel a bit contradictry to me, if every XHR request creates a transaction, how come the header is not attached at the time of a request.

I've already shared my debug logs with the support and last email received from the support is:
"I'm partnering with a SDK engineer for this and I will get back to you as soon as I have an update."

And if somehow support made a wrong statement and header is only attached if an active transaction exists and not every xhr request creates a transaction, then I want to ask how limited is the automatic instrumentation?

Do I need to manually create a transaction for a possible interaction to have it traced through frontend and backend? Isn't there an option to create a transaction automatically when an XHR request about to happen without me manually trying to figure out if a transaction exists at the time of the request and if not create it every time?

For example on initial page load, we have about 8 api calls to our backend and sometimes 4 some times 3 out of 8 has the necessary header. Specially the first 3 calls made never has the header.

Then for example there is a button on the ui that calls an endpoint and backend rejects it. There is no trace header on the request so we are not able to follow the event to the backend. Event is visible individually for frontend and backend. But we do not have a breakdown the complete picture.

Just in case; my sampling is set to 1.0 and I'm really hoping I'm doing something wrong and there is a way to add the header to all xhr request for the given origins without doing manual work there..

I'm using the following packages:

"@sentry/tracing": "^6.13.3"
"@sentry/vue": "^6.13.3"

[fliespl]

@kamilogorek can you explain how to attach next XHR / Fetch events after pageload transaction finishes?

I am getting pageload transaction logged, but I also want to metric later on xhr/fetch requests (which of course don't have sentry-trace header cause transaction is gone).

[ydennisy]

@kamilogorek this is still an active issue - please could you re-open and provide a workaround for Vue?

[kamilogorek]

@ydennisy please open a new issue so that team can triage it, thanks!

[adzza24]

Was there a new ticket for this one? Still seeing this issue, even when I manually create and open a transaction before the XHR request and don't close it until the response is received. Even with tracesSampleRate set to 1.0 I still only ever get sentry-trace and baggage headers added on the first 2 requests which run whilst the page is loading.

[yarinsa]

Was this ever resolved? I am not seeing sentry-trace on any of my requests

[mmahalwy]

Found the solution. Was working in development but not in prod. Then I discovered it's because you have to see the tracingOrigins yourselves and localhost is the default. See:
https://github.com/getsentry/sentry-javascript/blob/master/packages/tracing/src/browser/request.ts#L17-L23

[laygir]

@mmahalwy I hope that was the issue with your situation.

But I think it is not the solution..
I have inserted right values in the tracingOrigins and behaviour was still the same for me.

The problem appears to be that Sentry only attaches the header if there is an ongoing transaction.
Since transactions don't keep open, not all your requests will have the header.

I guess you could work around this and create a transaction every time you are about to make a fetch request, but this is not nice considering what they called "automated instrumentation". If I need to handle all that stuff, how is that an automated instrumentation.. Marketing bs..
And what they offer as APM is not an APM.. Compare it with what you get from New Relic and see your self which one is an actual APM. (from backend services point of view)

I have the following issue created as this one was closed. And it is marked as bug by the Sentry team..
#4072

But still, even after 3 written assurances by email from 1 sales person and 2 times by a support person that this issue was going to be fixed in "a few weeks", we are approaching the anniversary of it and still unresolved.

Company I'm working in is a paid customer for 5 years and because this has been an issue for us, we are not able upgrade our account because we can't use these transactions without header as they don't get associated with other transactions, there is no point in that..

So I'm sure there is subscription/growth attached to this problem for the product and Sentry is choosing not to fix it.

My 5 cents on this: the last few years they got some investments coming in and since then the dynamics in the company are changing and this reflects on the product obviously..