apache/dubbo

[Bug] When subscribing to the same service from multiple registry centers in Dubbo 3.3.4, subscription relationships are not handled correctly.

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#15761 opened on Nov 7, 2025

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

3.3.4

Steps to reproduce this issue

For example: There's a service called com.a.b.QuotaService available in both registry centers "registrySt" and "registryOnline". Now I subscribe to them in my service like this:

@Reference(group = "", registry = "registrySt", interfaceClass = QuotaService.class, check = false, retries = 0, timeout = 3000) private QuotaService quotaServiceSt;

@Reference(group = "", registry = "registryOnline", interfaceClass = QuotaService.class, check = false, retries = 0, timeout = 5000) private QuotaService quotaServiceOnline;

During project initialization and subscription, it goes through a cache logic where the key obtained is "com.a.b.QuotaService" in both cases. This means the first one can initialize properly, but the second one reuses what's in the cache because the key is the same.

What you expected to happen

However, for my use case, these two References should be independent and shouldn't be reused.

Anything else

No response

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
backendapi
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.
mostly clear
Prerequisites
Understanding of Dubbo service subscriptionJava debugging skills
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
30
Research direction
Examine the cache key logic in Dubbo's subscription mechanism, likely in classes like ReferenceConfig or RegistryDirectory. The issue describes that the key only includes the service name (com.a.b.QuotaService) without the registry identifier, causing collisions when the same service is subscribed via different registries. The fix should incorporate the registry identity into the cache key. Start by searching for where subscription caches are built, e.g., in `org.apache.dubbo.config.ReferenceConfig` or `org.apache.dubbo.registry.integration.RegistryDirectory`. The comments may provide additional clues.