[Bug] Compatibility issues when migrating from Dubbo 2.5.x to 3.3.x · apache/dubbo#16046

2026-01-24T13:38:54.000Z

### Pre-check - [x] I am sure that all the content I provide is in English. ### Search before asking - [x] I had searched in the [issues](https://github.com/apache/dubbo/issues?q=is%3Aissue) and found no similar issues. ### Apache Dubbo Component Java SDK (apache/dubbo) ### Dubbo Version Dubbo 3.3.5, JDK 1.8, Linux ### Steps to reproduce this issue When migrating Dubbo2.5.x project up to 3.3.x, there are two issues found. 1. If there are two registry defined, but their properties are all same except the Id of registry. This is ok with Dubbo 2.5.x, but the project cannot start with Dubbo 3.3.x. 2. If there is dubbo:annoation in the xml config, the project cannot start with Dubbo 3.3.x ### What you expected to happen It should be smooth during migration up to 3.3.x. ### Anything else _No response_ ### 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? - [x] Yes I am willing to submit a pull request on my own! ### Code of Conduct - [x] I agree to follow this project's [Code of Conduct](https://www.apache.org/foundation/policies/conduct)

(7 留言) (0 反應) (0 負責人)Java (41,524 star) (26,453 fork)batch import

help wanted

描述

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 3.3.5, JDK 1.8, Linux

Steps to reproduce this issue

When migrating Dubbo2.5.x project up to 3.3.x, there are two issues found.

If there are two registry defined, but their properties are all same except the Id of registry. This is ok with Dubbo 2.5.x, but the project cannot start with Dubbo 3.3.x.
If there is dubbo:annoation in the xml config, the project cannot start with Dubbo 3.3.x

What you expected to happen

It should be smooth during migration up to 3.3.x.

Anything else

No response

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

I agree to follow this project's Code of Conduct

貢獻者指南

技術棧: java
領域: backend
議題類型: bug
難度: 3
預計時間: 1-2 days
活動狀態: fresh
清晰度: clear
前置要求: JavaDubbo frameworkXML configuration
新手友善度: 40
研究方向: The issue describes two compatibility bugs when migrating from Dubbo 2.5.x to 3.3.x. First, duplicate registries with identical properties except ID cause startup failure; investigate how Dubbo 3.3.x validates registry definitions, possibly in RegistryConfig or related XML parsing. Second, dubbo:annotation in XML fails; check how annotations are processed in the new version. Look at the Dubbo source code (e.g., org.apache.dubbo.config.spring.beans.factory.annotation) and XML schema parsing (spring.schemas, etc.). Also review existing tests for migration scenarios.