apache/dubbo

[Bug] The traffic will be routed to instances of previous interface, which causes no such method error

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#16131 opened on Mar 13, 2026

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 (2 comments) (0 reactions) (0 assignees)Java (41,524 stars) (26,453 forks)batch import
help wanted

Description

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

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

Apache Dubbo Component

Java SDK (apache/dubbo)

Dubbo Version

Dubbo 3.3.6, JDK 1.8

Steps to reproduce this issue

Prepare two interfaces in different application, and invoke the interfaces one by one. The invocation of second interface will have no such method error.

What you expected to happen

The traffic should be always go to correct instances.

Anything else

After debugging, the issue is at the lines below in AbstractDirectory

/**
     * All invokers from registry
     */
    private volatile BitList<Invoker<T>> invokers = BitList.emptyList();

The invokes are initiated by BitList.emptyList(), and the emptyList() returns a variable of empty list. However, the invokers variable get the reference of emptyList, and changes happens in the first invocation of the first interface. When the second interface is invoked, the invokes are not empty, but the instances of the previous instances of the first interface.

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
JavaApache Dubbo basicsConcurrency in Java
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
60
Research direction
The bug is in AbstractDirectory.java where the invokers field is initialized with BitList.emptyList() which returns a static empty list that is later mutated. To fix, ensure each interface gets a new empty list instance, e.g., by using new BitList<>() or cloning. Investigate the BitList implementation and confirm that emptyList() indeed returns a mutable list. Then replace the initialization in AbstractDirectory to create a new empty list each time. Also verify that this change does not affect other parts of the code that rely on the singleton behavior.