DBLE 2.20.04.0 Release Notes and Detailed Analysis

DBLE (also known as “MyCat Plus”) is an enterprise‑grade open‑source distributed middleware that provides data sharding, read/write separation, distributed transaction support, global IDs, and IP/SQL black‑white lists. The project’s official repository is https://github.com/actiontech/dble , and its documentation is available at https://actiontech.github.io/dble-docs-cn .

Version 2.20.04.0 is the second release of DBLE in the current year. It introduces 13 new or refactored features, fixes 21 defects, and makes one backward‑compatibility adjustment. Notable new features include support for MySQL protocol packets larger than 16 MB and a redefined high‑availability failover mechanism.

Failover redesign : Starting with 2.20.04.0, the previous failover implementation is deprecated. Two HA modes are provided – an embedded Python‑3 script for single‑instance deployments (enabled by setting useOuterHa=false in server.xml ) and an external HA interface for clustered deployments (enabled by useOuterHa=true ). If no external component is configured, no action occurs. Detailed usage is described in the “High‑Availability Interface” and “2.12 Failover” documents.

Main updates also list support for larger MySQL packets and other functional enhancements.

Full Release Notes (Chinese) enumerate features such as flow‑control to avoid OOM, URL logging in heartbeats, multi‑statement support, XA transaction refactoring, security upgrades for Log4j and FastJSON, new manager commands (DROP DATABASE), group‑by push‑down standardization, and heap‑dump addition for OutOfMemory errors. The section also lists numerous bug fixes (e.g., spelling errors in server.xml , session hangs during DDL, NPEs in union queries, concurrency issues, and character‑encoding problems) and a breaking change that removes support for Multi‑WriteHost and SwitchType.

Release Notes (English) repeat the same feature list and bug‑fix details in English, providing direct links to the corresponding documentation files on GitHub.

Additional resources include download links for the release packages, official training courses ( DBLE Quick Start and DBLE Advanced Course ).

For further reading, the article links to recent technical posts about DBLE’s SQL parsing, global table checks, and view implementation.