apache/dubbo

[Bug] CompositeInputStream.close() may leak underlying streams when one close() throws

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#16117 opened on Mar 7, 2026

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help wanted

Description

Pre-check

  • I am sure that all the content I provide is in English.

Search before asking

  • I had searched in the issues and found no similar issues.

Apache Dubbo Component

Java SDK (apache/dubbo)

Dubbo Version

Dubbo Java 3.3, Ubuntu 20.04

Steps to reproduce this issue

Resource leak, non-deterministic.

What you expected to happen

CompositeInputStream.close() should attempt to close all underlying streams, even if one close() throws. After trying all closes, it should throw the first IOException and attach later close failures as suppressed exceptions (if any).

This prevents partial cleanup and potential resource leaks.

Anything else

Current behavior: CompositeInputStream.close() stops at the first IOException, leaving remaining streams unclosed.

Frequency: Every time an underlying stream’s close() throws.

Proposed fix: Wrap each close() in try/catch while draining the queue, collect the first IOException, suppress subsequent failures, and throw after attempting all closes.

Do you have a (mini) reproduction demo?

  • Yes, I have a minimal reproduction demo to help resolve this issue more effectively!

Are you willing to submit a pull request to fix on your own?

  • Yes I am willing to submit a pull request on my own!

Code of Conduct

Contributor guide

Tech stack
java
Domain
backend
Issue type
bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
fresh
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
Java exception handlingBasic I/O streams
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
70
Research direction
Examine the source code of `CompositeInputStream.close()` in the Apache Dubbo repository (likely in `dubbo common` module). The current implementation stops closing remaining underlying streams if one `close()` throws an `IOException`. Implement the proposed fix: wrap each `close()` call in a try catch block, collect the first `IOException` (if any), attach subsequent exceptions as suppressed exceptions, and then throw the first exception after attempting all closes. Add unit tests to verify that all streams are closed and that suppressed exceptions are correctly propagated. See the issue comments and the existing `InputStream` utility classes for reference.