Odd activity auto tracing duration

[LouisFn]

Platform:

• Android -> minSdk: 24, compileSdk: 30, targetSdk: 30, buildTools: 31.0.0
• Kotlin -> 1.5.31, jvmTarget: VERSION_11
• Timber -> 5.0.1

Build system:

• Gradle -> 7.2

_Android Gradle Plugin: 7.0.2

The version of the SDK:
5.2.0

---

I have the following issue:

We get odd result with activity auto tracing. We receive many transactions with a very long duration on prod.

[marandaneto]

@LouisFn thanks for reporting.

can you reproduce that?

https://docs.sentry.io/platforms/android/performance/instrumentation/automatic-instrumentation/#androids-activity-instrumentation

did you disable the io.sentry.traces.activity.auto-finish.enable config or is it enabled as it is by default?

can you give some more context? thanks

[LouisFn]

Sadly we can't reproduce that but in prod, there are 10% of the traces of our MainActivity which have invalid duration (more than 10min up to 30h) ...
No, we didn't disable io.sentry.traces.activity.auto-finish.enable.

[marandaneto]

@LouisFn did you find any pattern from this 10% of traces? like OS version, Device brand, or something.
I can't reproduce it either.

[LouisYubo]

No, we didn't find any pattern, it occurs on different android version and devices.

[marandaneto]

@LouisYubo I can't really reproduce it, not sure how to proceed, any ideas on how to reproduce otherwise I'd have to close it.

[marandaneto]

@LouisFn does your app have notifications? is it possible that users open your app via notification?

[LouisFn]

@marandaneto Completely, I can reproduce it by opening the app from notification

[marandaneto]

@LouisFn ok thats a good start, can you tell me the exact steps to reproduce it? or provide a minimal reproducible example? thanks

[LouisFn]

@marandaneto It seems to be because the lib wait for the child traces to finish before stoping the transaction (waitForChildren) and the child trace from FragmentLifecycleIntegration never ends.

It's due to NavDeepLinkBuilder, when the deep link is triggered, the destination and all of its parents will be on the back stack. But for its parents, only onCreate is called but not onResume. So the HomeFragment transaction never finished.

You can find a reproducible example here:
https://github.com/LouisFn/SentryFrozenFrame

BTW, I think it would be usefull to add an option to disable "waitForChildren"

[marandaneto]

will have a look, thanks

[marandaneto]

I can confirm that HomeFragment isn't calling onFragmentResumed

[marandaneto]

@LouisFn in your use case, maybe there's a bug in your example as well, you set:

app:startDestination="@id/navigation_fragment_home"

but in LaunchActivity, you set .setDestination(R.id.navigation_fragment_home), so HomeFragment isn't even visible or anything, looks like a wrong setup of the navigation-ui rather than the bug in Sentry SDK.

[marandaneto]

do setDestination and app:startDestination must match or not? didn't find docs for that, if they don't have to, maybe fixing on the SDK would make more sense.

[LouisYubo]

@LouisFn in your use case, maybe there's a bug in your example as well, you set:

app:startDestination="@id/navigation_fragment_home"

but in LaunchActivity, you set .setDestination(R.id.navigation_fragment_home), so HomeFragment isn't even visible or anything, looks like a wrong setup of the navigation-ui rather than the bug in Sentry SDK.

I don't understand what you mean, I set .setDestination(R.id.navigation_fragment_chat) no .setDestination(R.id.navigation_fragment_home) so it's normal if HomeFragment isn't visible

do setDestination and app:startDestination must match or not? didn't find docs for that, if they don't have to, maybe fixing on the SDK would make more sense.

No, the purpose is to navigate to a specific destination (not the start destination) while adding the start destination to the backstack.

From the docs: https://developer.android.com/reference/androidx/navigation/NavDeepLinkBuilder

When this deep link is triggered:
The task is cleared.
The destination and all of its parents will be on the back stack.
[...]
The parent of the destination is the start destination of the containing navigation graph.

[marandaneto]

sorry it was a typo, .setDestination(R.id.navigation_fragment_chat) indeed.

No, the purpose is to navigate to a specific destination (not the start destination) while adding the start destination to the backstack.

got it, that makes sense, since the fragment does not trigger any other lifecycle, I don't really know how to finish the span automatically for that case, ideas?

[marandaneto]

even if I provide a custom waitForChildren, how would you know if HomeFragment was just added to the back stack but never visible, programmatically?

[LouisYubo]

I think, you might check if fragment isAdded in onCreate before starting the trace ?

[marandaneto]

indeed @LouisYubo that's totally possible and it works, thanks for the tip, See PR #1813

[LouisYubo]

@marandaneto Thanks a lot for the fix :)

But I think there are others issues with the auto tracing activity that doesn't seem to be related to waitForChildren. For now I didn't managed to reproduce this case

or

App Startup - MainActivity#onCreate is a custom child span added to measure our onCreate implementation

[marandaneto]

@LouisYubo it could be related to opening the App thru notifications, mind testing that out? at least the sample that you have given is fixed, please raise a new issue with more detailed use case for the other one, also a minimal reproducible example would help as it did with this one, thanks a lot.