Dubbo2 Upgrade Dubbo3 Step Record

During the process of upgrading Dubbo2 to Dubbo3, there may be some common issues that you may encounter. You can share and learn from each other the stepping records during the upgrade process.

dubbo2升级dubbo3过程中可能会遇到一些比较常见的问题 大家升级中的踩坑记录可以分享下，相互借鉴。

The issue names no files, tests, or entry points. Start by clarifying whether the intended outcome is a documentation page or a discussion of Dubbo2-to-Dubbo3 migration pitfalls; done would require a defined location and a curated set of upgrade records.

Written by the indexing model from the issue text.