fix(okhttp): Don't block on response bodies by reading the body upfront by markushi · Pull Request #6231 · getsentry/sentry-java

markushi · 2026-10-07T05:55:44Z

📜 Description

SentryOkHttpInterceptor captured the response body with peekBody(MAX_NETWORK_BODY_SIZE + 1). A peek
is request(n), which waits for n bytes or for the end of the stream — a body with no
Content-Length delivers neither, so the interceptor never returned and the application never
received the response.

Every response body now goes through the new CapturedResponseBody, which copies the bytes the
application reads into a capped buffer. Nothing is read for the capture itself. The status code and
the headers are recorded before anything is consumed, so a stream that stays open still produces a
usable breadcrumb.

💡 Motivation and Context

With Session Replay network details enabled for a URL, every Server-Sent Events, long-poll or open
chunked endpoint hung forever or failed with a SocketTimeoutException. Gzipped responses were
affected too: OkHttp strips Content-Length when it decompresses, so an application interceptor sees
-1.

Continues carlonzo#1 by @carlonzo

Fixes #6138

💚 How did you test it?

Added unit tests, including a regression test that hangs without the fix.

📝 Checklist

I added GH Issue ID & Linear ID
I added tests to verify the changes.
No new PII added or SDK only sends newly added PII if sendDefaultPII is enabled.
I updated the docs if needed.
I updated the wizard if needed.
Review from the native team if needed.
No breaking change or entry added to the changelog.
No breaking change for hybrid SDKs or communicated to hybrid SDKs.
Public API changes reviewed by another Mobile SDK team member or implemented according to the develop docs spec.

🔮 Next steps

Capturing a response body for session replay peeked it up front with `Response.peekBody(MAX_NETWORK_BODY_SIZE + 1)`. OkHttp implements a peek as `request(byteCount)`, which keeps reading until that many bytes are buffered or the stream ends. A response with no Content-Length never satisfies either condition, so for server-sent events, long-poll and any chunked endpoint that stays open the interceptor never returned and the caller never received the response at all. Bodies with a known length still end on their own, so they keep the existing up-front capture. Bodies of unknown length are now wrapped in a body that copies what the application consumes into a capped buffer and reports it once no more bytes can arrive: when the stream ends, when the application closes the body, or when the cap is reached. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Split the capture wrapping into its own function to keep a single return, and suppress TooManyFunctions on the interceptor as done elsewhere in this module.

A response body has a single consumer, and neither Http1ExchangeCodec.cancel() nor Http2ExchangeCodec.cancel() closes the body, so nothing reaches this class from another thread. The AtomicBoolean already guarantees the capture is reported exactly once.

A streamed body is only known once it has been consumed, which can be after the NetworkRequestData carrying it was handed to the scope, so the replay thread can read it while it is still being written. Keeping the three response values behind one volatile reference means a reader sees either nothing or the complete set.

sentry · 2026-10-07T06:42:36Z

📲 Install Builds

Android

🔗 App Name	App ID	Version	Configuration
SDK Size	io.sentry.tests.size	8.63.0 (1)	release

⚙️ sentry-android Build Distribution Settings

…nseBody

…shepherd] Co-Authored-By: Markus Hintersteiner <markus.hintersteiner@sentry.io>

…shepherd] # Conflicts: # CHANGELOG.md Co-Authored-By: Markus Hintersteiner <markus.hintersteiner@sentry.io>

…over

…ture errors

0xadam-brown

Thanks a bunch for this 💯 ! A few comments from my end below.

Also, out of scope for now, but it looks like there might be a request-side version of this bug, in that the request body is still read into memory before the request is sent (link). Presumably that means streaming, duplex, or large uploads to an allowlisted URL can hang / lose data / trigger an OOM.

Let me know if you want me to open an issue 👍

…shepherd]

cursor

Stale Bugbot comment from a previous run.

…getsentry/sentry-java into fix/okhttp-unknown-length-response-body

0xadam-brown

Thanks for the updates - looking great!

A few possibilities I noticed on a second pass. Otherwise nice all around 👍

…shepherd]

cursor

Stale Bugbot comment from a previous run.

…replay

runningcode

LGTM!

cursor

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carlonzo and others added 14 commits October 6, 2026 13:32

changelog: reference the pull request

4d7c686

fix(okhttp): Satisfy detekt for the streaming body capture

554d121

Split the capture wrapping into its own function to keep a single return, and suppress TooManyFunctions on the interceptor as done elsewhere in this module.

test: Cover late-filled network request data

1c6174f

fix(okhttp): Harden the capture of response bodies with no known length

9377594

test(okhttp): Cover async, cancelled and HTTP/2 bodies of unknown length

a93c694

ref: Publish both sides of NetworkRequestData the same way

b77f96a

fix(okhttp): Keep the bytes received before a stream breaks

17d5134

ref: Read the response details of a network breadcrumb as one snapshot

f9e79c0

ref(okhttp): Capture every response body through one path

5b2bf58

changelog

8879de2

test: Silence R8 for the okhttp types the new response body extends

09687ef

markushi and others added 9 commits October 8, 2026 13:27

ref(okhttp): Rename NetworkBodyCapturingResponseBody to CapturedRespo…

ead659c

…nseBody

ref(okhttp): Capture only the response bytes the application reads

8193c36

Merge branch 'main' into fix/okhttp-unknown-length-response-body [pr-…

406bd4e

…shepherd] Co-Authored-By: Markus Hintersteiner <markus.hintersteiner@sentry.io>

Merge branch 'main' into fix/okhttp-unknown-length-response-body [pr-…

d490996

…shepherd] # Conflicts: # CHANGELOG.md Co-Authored-By: Markus Hintersteiner <markus.hintersteiner@sentry.io>

test(okhttp): Wait for the capture, not for the source handing bytes …

6a5a086

…over

ref: Keep the status code inside the response details

b406d8b

ref(okhttp): Restore the original response flow and rethrow fatal cap…

ab94b11

…ture errors

ref(okhttp): Drop comments that restate the code

7c50f57

ref: Drop the constructor comment on ReplayNetworkRequestOrResponse

fa85e61

markushi marked this pull request as ready for review October 22, 2026 07:43

markushi requested review from 0xadam-brown, adinauer, romtsn and runningcode as code owners October 22, 2026 07:43

markushi changed the title ~~fix(okhttp): Don't block on response bodies with no known length~~ fix(okhttp): Don't block on response bodies by reading the body upfront Oct 22, 2026

markushi added the sanity-check PR needs a lightweight review for obvious issues label Oct 22, 2026

0xadam-brown reviewed Oct 22, 2026

View reviewed changes

Merge branch 'main' into fix/okhttp-unknown-length-response-body [pr-…

4dbcbfa

…shepherd]

cursor Bot reviewed Oct 22, 2026

View reviewed changes

Comment thread sentry-okhttp/src/main/java/io/sentry/okhttp/CapturedResponseBody.kt Resolved

Comment thread sentry-okhttp/src/main/java/io/sentry/okhttp/SentryOkHttpInterceptor.kt Resolved

Address PR comments

c875cd0

getsentry deleted a comment from sentry-junior Bot Oct 23, 2026

Merge branch 'fix/okhttp-unknown-length-response-body' of github.com:…

2bc6c4f

…getsentry/sentry-java into fix/okhttp-unknown-length-response-body

0xadam-brown reviewed Oct 23, 2026

View reviewed changes

Merge branch 'main' into fix/okhttp-unknown-length-response-body [pr-…

da019c0

…shepherd]

cursor Bot reviewed Oct 27, 2026

View reviewed changes

Comment thread sentry-okhttp/src/main/java/io/sentry/okhttp/SentryOkHttpInterceptor.kt Resolved

Comment thread sentry-okhttp/src/main/java/io/sentry/okhttp/CapturedResponseBody.kt Resolved

markushi added 2 commits November 4, 2026 13:34

address PR comments

2599f05

test(replay): Pin the response body a late capture leaves out of the …

0e2906b

…replay

markushi requested a review from a team as a code owner November 5, 2026 08:43

runningcode approved these changes Nov 6, 2026

View reviewed changes

Comment thread sentry-okhttp/src/main/java/io/sentry/okhttp/SentryOkHttpInterceptor.kt Resolved

markushi mentioned this pull request Nov 6, 2026

fix(okhttp): Capture network details only while Session Replay is recording #6486

Merged

5 of 9 tasks

markushi enabled auto-merge (squash) November 6, 2026 08:34

markushi mentioned this pull request Nov 6, 2026

test(spring-boot): Keep the Log4j2 LoggerContext reachable in appender auto-configuration tests #6488

Merged

4 of 9 tasks

Merge branch 'main' into fix/okhttp-unknown-length-response-body

affe3d6

cursor Bot reviewed Nov 6, 2026

View reviewed changes

Comment thread sentry-okhttp/src/main/java/io/sentry/okhttp/SentryOkHttpInterceptor.kt Resolved

fix changelog entry

6031c4e

markushi merged commit 1a746d7 into main Nov 6, 2026
49 of 50 checks passed

markushi deleted the fix/okhttp-unknown-length-response-body branch November 6, 2026 11:45

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📜 Description

💡 Motivation and Context

💚 How did you test it?

📝 Checklist

🔮 Next steps

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📲 Install Builds

Android

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