Sentry Session Replay File Descriptor Leak

[vilorel]

Platform

Flutter Mobile iOS

Obfuscation

Enabled

Debug Info

Enabled

Doctor

flutter doctor
Doctor summary (to see all details, run flutter doctor -v):
[✓] Flutter (Channel stable, 3.41.1, on macOS 26.2 25C56 darwin-arm64, locale en-US)
[✓] Android toolchain - develop for Android devices (Android SDK version 36.1.0-rc1)
[✓] Xcode - develop for iOS and macOS (Xcode 26.2)
[✓] Chrome - develop for the web
[✓] Connected device (4 available)
[✓] Network resources

• No issues found!

Version

9.13.0

Steps to Reproduce

The app froze due to the process exhausting its file descriptor limit (EMFILE / errno-24), triggered by Sentry's session replay feature running continuously while being rate-limited by the Sentry server.

Timeline (app started at 13:07:21)

1. 13:07 – Normal startup. The AVC video encoder (c2.android.avc.encoder) starts cycling for Sentry session replay — allocating codecs, buffer pools, MPEG4
   writers, encoding a few frames, then resetting. This cycle repeats at least 6 times visible in the log.
2. Sentry 429 rate limiting begins. Sentry's server rejects replay envelopes with HTTP 429 (lines 1118, 1516, 1854):
   "Sentry dropped data due to a quota or internal rate limit being reached."
3. Despite being rate-limited, the replay keeps recording — each cycle allocates new codec instances, buffer pools, and file handles that are not being reclaimed
   properly.
4. ~13:18 – File descriptor limit reached. The cascade of failures begins:

- Line 2031 — Vulkan swapchain dies: Could not acquire next swapchain image: ErrorOutOfHostMemory
- Line 2032 — GPU surface gone: No surface available
- Line 2033 — Impeller fence waiter tears down: Fence waiter encountered an unexpected error. Tearing down the waiter thread.

This is a fatal, unrecoverable GPU rendering failure — Flutter/Impeller can no longer draw any frames.
4. Post-crash fallout (all caused by Too many open files):
[...]

Expected Result

The library should close codecs/buffers when rate-limited and limit is hit or not (re)attempt the recording in the first place.

Actual Result

D/Sentry (32718): Request failed, API returned 429
D/Sentry (32718): {"detail":"Sentry dropped data due to a quota or internal rate limit being reached. This will not affect your application. See https://docs.sentry.io/product/accounts/quotas/ for more information."}
D/Sentry (32718): The transport failed to send the envelope with response code 429
D/CCodec (32718): allocate(c2.android.avc.encoder)
E/Sentry (32718): Envelope submission failed
E/Sentry (32718): java.lang.IllegalStateException: The transport failed to send the envelope with response code 429
E/Sentry (32718): at io.sentry.transport.AsyncHttpTransport$EnvelopeSender.flush(AsyncHttpTransport.java:322)
E/Sentry (32718): at io.sentry.transport.AsyncHttpTransport$EnvelopeSender.run(AsyncHttpTransport.java:247)
E/Sentry (32718): at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:520)
E/Sentry (32718): at java.util.concurrent.FutureTask.run(FutureTask.java:317)
E/Sentry (32718): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1154)
E/Sentry (32718): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:652)
E/Sentry (32718): at java.lang.Thread.run(Thread.java:1564)
I/CCodec (32718): setting up 'default' as default (vendor) store
W/xxxx(32718): AIBinder_linkToDeath is being called with a non-null cookie and no onUnlink callback set. This might not be intended. AIBinder_DeathRecipient_setOnUnlinked should be called first.
I/CCodec (32718): Created component [c2.android.avc.encoder] for [c2.android.avc.encoder]
D/CCodecConfig(32718): read media type: video/avc
D/ReflectedParamUpdater(32718): extent() != 1 for single value type: algo.buffers.max-count.values
D/ReflectedParamUpdater(32718): extent() != 1 for single value type: output.subscribed-indices.values
D/ReflectedParamUpdater(32718): extent() != 1 for single value type: input.buffers.allocator-ids.values
D/ReflectedParamUpdater(32718): extent() != 1 for single value type: output.buffers.allocator-ids.values
D/ReflectedParamUpdater(32718): extent() != 1 for single value type: algo.buffers.allocator-ids.values
D/ReflectedParamUpdater(32718): extent() != 1 for single value type: output.buffers.pool-ids.values
D/ReflectedParamUpdater(32718): extent() != 1 for single value type: algo.buffers.pool-ids.values
D/ReflectedParamUpdater(32718): ignored struct field coding.gop.values
D/ReflectedParamUpdater(32718): ignored struct field coding.qp.values
D/CCodecConfig(32718): ignoring local param raw.color (0xc2001809) as it is already supported
I/CCodecConfig(32718): query failed after returning 13 values (BAD_INDEX)
D/CCodecConfig(32718): c2 config diff is Dict {
D/CCodecConfig(32718): c2::u32 algo.bitrate-mode.value = 3
D/CCodecConfig(32718): c2::i32 coded.average-qp.value = 0
D/CCodecConfig(32718): c2::u32 coded.bitrate.value = 64000
D/CCodecConfig(32718): c2::float coded.frame-rate.value = 1
D/CCodecConfig(32718): c2::u32 coded.picture-type.value = 0
D/CCodecConfig(32718): c2::u32 coded.pl.level = 20492
D/CCodecConfig(32718): c2::u32 coded.pl.profile = 20481
D/CCodecConfig(32718): c2::u32 coded.vui.color.matrix = 0
D/CCodecConfig(32718): c2::u32 coded.vui.color.primaries = 0
D/CCodecConfig(32718): c2::u32 coded.vui.color.range = 0
D/CCodecConfig(32718): c2::u32 coded.vui.color.transfer = 0
D/CCodecConfig(32718): c2::u32 coding.intra-refresh.mode = 0
D/CCodecConfig(32718): c2::float coding.intra-refresh.period = 0
D/CCodecConfig(32718): c2::u32 coding.request-sync-frame.value = 0
D/CCodecConfig(32718): c2::i64 coding.sync-frame-interval.value = 1000000
D/CCodecConfig(32718): c2::u32 input.delay.value = 0
D/CCodecConfig(32718): string input.media-type.value = "video/raw"
D/CCodecConfig(32718): string output.media-type.value = "video/avc"
D/CCodecConfig(32718): c2::u32 raw.color.matrix = 0
D/CCodecConfig(32718): c2::u32 raw.color.primaries = 0
D/CCodecConfig(32718): c2::u32 raw.color.range = 0
D/CCodecConfig(32718): c2::u32 raw.color.transfer = 0
D/CCodecConfig(32718): c2::u32 raw.size.height = 16
D/CCodecConfig(32718): c2::u32 raw.size.width = 16
D/CCodecConfig(32718): }
W/ColorUtils(32718): expected specified color aspects (0:0:0:0)
D/MPEG4Writer(32718): PreAllocation enabled
I/MediaCodec(32718): media_quality service unavailable, skipping updatePictureProfile
D/VQApply (32718): raise bitrate: configured 1 to floor 1158144
D/VQApply (32718): minquality by QP: inject video-qp-max=38
D/VQApply (32718): minquality/target bitrate raised from 1 to 1158144 bps
D/MediaCodec(32718): shapeMediaFormat: deltas(6): AMessage(what = 0x00000000) = {
D/MediaCodec(32718): int32_t bitrate = 1158144
D/MediaCodec(32718): int32_t android._encoding-quality-level = 0
D/MediaCodec(32718): int32_t video-qp-max = 38
D/MediaCodec(32718): int32_t video-qp-i-max = 38
D/MediaCodec(32718): int32_t video-qp-p-max = 41
D/MediaCodec(32718): int32_t video-qp-b-max = 44
D/MediaCodec(32718): }
D/CCodec (32718): [c2.android.avc.encoder] buffers are bound to CCodec for this session
D/CCodecConfig(32718): no c2 equivalents for color-format
D/CCodecConfig(32718): no c2 equivalents for video-qp-max
D/CCodecConfig(32718): no c2 equivalents for video-qp-i-max
D/CCodecConfig(32718): no c2 equivalents for video-qp-p-max
D/CCodecConfig(32718): no c2 equivalents for video-qp-b-max
D/CCodecConfig(32718): no c2 equivalents for flags
D/CCodecConfig(32718): no c2 equivalents for encoder
D/CCodecConfig(32718): c2 config diff is c2::u32 coded.bitrate.value = 1158144
D/CCodecConfig(32718): c2::i64 coding.sync-frame-interval.value = 6000000
D/CCodecConfig(32718): c2::u32 raw.size.height = 928
D/CCodecConfig(32718): c2::u32 raw.size.width = 416
W/ColorUtils(32718): expected specified color aspects (0:0:0:0)
D/CCodec (32718): encoding statistics level = 0
D/CCodec (32718): setup formats input: AMessage(what = 0x00000000) = {
D/CCodec (32718): Rect crop(0, 0, 415, 927)
D/CCodec (32718): int32_t color-standard = 0
D/CCodec (32718): int32_t color-range = 0
D/CCodec (32718): int32_t color-transfer = 0
D/CCodec (32718): int32_t frame-rate = 1
D/CCodec (32718): int32_t height = 928
D/CCodec (32718): int32_t intra-refresh-period = 0
D/CCodec (32718): string mime = "video/raw"
D/CCodec (32718): int32_t video-qp-average = 0
D/CCodec (32718): int32_t width = 416
D/CCodec (32718): int32_t android._dataspace = 0
D/CCodec (32718): int32_t using-sw-read-often = 1
D/CCodec (32718): int64_t android._C2MemoryUsage = 1
D/CCodec (32718): int32_t color-format = 2130708361
D/CCodec (32718): int32_t android._color-format = 2130708361
D/CCodec (32718): }
D/CCodec (32718): setup formats output: AMessage(what = 0x00000000) = {
D/CCodec (32718): int32_t bitrate = 1158144
D/CCodec (32718): int32_t bitrate-mode = 1
D/CCodec (32718): Rect crop(0, 0, 415, 927)
D/CCodec (32718): int32_t color-standard = 0
D/CCodec (32718): int32_t color-range = 0
D/CCodec (32718): int32_t color-transfer = 0
D/CCodec (32718): int32_t frame-rate = 1
D/CCodec (32718): int32_t height = 928
D/CCodec (32718): int32_t intra-refresh-period = 0
D/CCodec (32718): int32_t level = 4096
D/CCodec (32718): int32_t max-bitrate = 1158144
D/CCodec (32718): string mime = "video/avc"
D/CCodec (32718): int32_t profile = 65536
D/CCodec (32718): int32_t video-qp-average = 0
D/CCodec (32718): int32_t width = 416
D/CCodec (32718): }
I/CCodecConfig(32718): query failed after returning 14 values (BAD_INDEX)
E/xxxxx(32718): Failed to query component interface for required system resources: 6
D/CCodec (32718): aidl based PersistentSurface created
D/CCodec (32718): input format changed to AMessage(what = 0x00000000) = {
D/CCodec (32718): Rect crop(0, 0, 415, 927)
D/CCodec (32718): int32_t color-standard = 1
D/CCodec (32718): int32_t color-range = 2
D/CCodec (32718): int32_t color-transfer = 3
D/CCodec (32718): int32_t frame-rate = 1
D/CCodec (32718): int32_t height = 928
D/CCodec (32718): int32_t intra-refresh-period = 0
D/CCodec (32718): string mime = "video/raw"
D/CCodec (32718): int32_t video-qp-average = 0
D/CCodec (32718): int32_t width = 416
D/CCodec (32718): int32_t android._dataspace = 260
D/CCodec (32718): int32_t using-sw-read-often = 1
D/CCodec (32718): int64_t android._C2MemoryUsage = 1
D/CCodec (32718): int32_t color-format = 2130708361
D/CCodec (32718): int32_t android._color-format = 2130708361
D/CCodec (32718): }
D/GraphicBufferSource(32718): setting dataspace: 0x10c10000, acquired=0
D/CCodec (32718): ISConfig not changed
D/CCodecBufferChannel(32718): [c2.android.avc.encoder#434] Created input block pool with allocatorID 17 => poolID 18 - OK (0)
I/CCodecBufferChannel(32718): [c2.android.avc.encoder#434] Created output block pool with allocatorID 16 => poolID 174 - OK
D/CCodecBufferChannel(32718): [c2.android.avc.encoder#434] Configured output block pool ids 174 => OK
D/GraphicBufferSource(32718): got buffer with new dataSpace 0x8810000
D/C2NodeImpl(32718): dataspace changed to 0x8810000 pixel format: 0x1
D/CCodecConfig(32718): c2 config diff is Buffer coded.init-data.value = {
D/CCodecConfig(32718): 00000000: 00 00 00 01 67 42 c0 29 8d 68 1a 07 5a 46 02 1a ....gB.).h..ZF..
D/CCodecConfig(32718): 00000010: 02 0f 08 84 6a 00 00 00 01 68 ce 01 a8 35 c8 ....j....h...5.
D/CCodecConfig(32718): }
D/MPEG4Writer(32718): fpathconf _PC_FILESIZEBITS:64
D/MPEG4Writer(32718): File size limit set to 4503599627370495 bytes implicitly
D/MPEG4Writer(32718): MP4WtrCtrlHlpLooper Started
I/MPEG4Writer(32718): limits: 4503599627370495/0 bytes/us, bit rate: -1 bps and the estimated moov size 3192 bytes
I/MPEG4Writer(32718): setStartTimestampUs: 0
I/MPEG4Writer(32718): Earliest track starting time: 0
D/MPEG4Writer(32718): reset()
D/MPEG4Writer(32718): Video track stopping. Stop source
D/MPEG4Writer(32718): Video track source stopping
D/MPEG4Writer(32718): Video track source stopped
V/MediaWriter(32718): Track event err/info msg:101, trackId:1, type:1000,val:-1011
I/MPEG4Writer(32718): Received total/0-length (2/0) buffers and encoded 2 frames. - Video
D/MPEG4Writer(32718): Video track stopped. Status:0. Stop source
D/MPEG4Writer(32718): 0 chunks are written in the last batch
D/MPEG4Writer(32718): WriterThread stopped. Status:0
I/MPEG4Writer(32718): Adjust the moov start time from 0 us -> 0 us
I/MPEG4Writer(32718): MOOV atom was written to the file
D/MPEG4Writer(32718): release()
D/MPEG4Writer(32718): ftruncate mPreAllocateFileEndOffset:26735 mOffset:809 mMdatEndOffset:25291 diff:1444
D/AidlBufferPool(32718): Destruction - bufferpool2 0xb400007311c6c618 cached: 0/0M, 0/0% in use; allocs: 0, 0% recycled; transfers: 0, 0% unfetched
D/MPEG4Writer(32718): final fsync() takes 5 ms, file size 25291
D/MPEG4Writer(32718): MP4WtrCtrlHlpLooper stopped
D/MPEG4Writer(32718): Top 5 write durations(microseconds): #1:27 #2:44 #3:50 #4:67 #5:76
D/MPEG4Writer(32718): reset()
D/MPEG4Writer(32718): Video track stopping. Stop source
E/MPEG4Writer(32718): Stop() called but track is not started or stopped
W/Sentry (32718): 1 envelope items will be dropped due rate limiting.
W/Sentry (32718): Envelope discarded due all items rate limited.
D/AidlBufferPoolAcc(32718): evictor expired: 1, evicted: 0
D/AidlBufferPoolAcc(32718): evictor expired: 1, evicted: 0
[...]

Are you willing to submit a PR?

None

[linear]

DART-313

[buenaflor]

I believe this is an issue of getsentry/sentry-cocoa#6618

The transport now correctly discard envelopes on 4xx and 5xx responses and records client reports send_error (#6618) This also fixes edge cases in which the SDK kept retrying sending a faulty envelope until the offline cache overflowed.

I'd have a look at a workaround or if we can backport it on cocoa because this is currently only fixed on v9 of cocoa (we are on v8 in Flutter)

[vilorel]

Thanks for the swift response. Interestingly enough it is not just a cocoa error. It does occur there too, but this report is in fact from an android deployment to a test device.
The error is catastrophic as the whole UI becomes unresponsive after it eats up all the available resources. The only solution is to turn it off. I've noticed it on occasions where I left the phone with the screen open for quite a while so normal use should not trigger it as frequently.

[buenaflor]

@romtsn wdyt? on Android should we instead not create segments when being rate limited?