Transactions aren't capturing async child spans

[jpike88]

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• Search for existing issues: https://github.com/getsentry/sentry-javascript/issues
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Package + Version

• @sentry/node

Version:

6.5.1

Description

const transaction = Sentry.startTransaction({
					op: encodedApiFunctionToRealName[finalPublicMethodName],
					name: encodedApiFunctionToRealName[finalPublicMethodName],
				});

				try {
					const result = await auth(accessToken);
transaction.finish();
}
})

In the above code, many mysql functions are running, but none of the spans are showing up in the log. I breakpointed inside @sentry/tracing/dist/integrations/mysql.js, and the problem seems to be this code is failing:

const parentSpan = scope?.getSpan();

getSpan() returns undefined.

The transaction logic doesn't seem to be very 'smart', it's not propagating the scope properly via the stack.

This is a big problem for our business, we want to switch to your product from Elastic APM but this makes that untenable.

[jpike88]

The elastic-apm-node library may provide some insight on how to redesign things better

[AdriVanHoudt]

You might need to do

        Sentry.configureScope((scope) => {

            scope.setSpan(transaction);
        });

[jpike88]

I'll try within the next hour. Why isn't that done by default?

[AdriVanHoudt]

No clue 🤷 , it is in the example on https://docs.sentry.io/platforms/node/performance/

[jpike88]

wtf it actually worked. but this to me still seems like bizarre/unexpected behaviour and warrants further explanation or maybe a fix

[AdriVanHoudt]

My guess would be that you need to do this for your 'root' transaction but startTransaction doesn't know if it is the 'root' one so it can't do it automatically. But no clue if that is actually the reason :D
Glad it works now for you.

Since you're switching you might run into #3660 as well btw.

[jpike88]

Yeah weird. With elastic-apm-node I just had an init call, and a simple one liner in the block of interest, no need to finish it or call any weird methods:

apm.setTransactionName('blah');

I hope this lib can learn from the others and implement a simpler approach.

[smeubank]

it actually worked.

we are aware of this issue, and at least for this specific topic it appears a fix was possible so I will close the issue and we address overarching topic internally