分佈式 | DBLE Release Notes 詳細解讀 2.19.05.0

原創做者：愛可生開源社區

2.19.05.0 版本

DBLE Release Notes

如下對 DBLE 2.19.05.0 版本的 Release Notes 進行詳細解讀。

文章主要分爲四部份內容：

1、DBLE 項目介紹

2、更新概況

3、新特性

4、升級兼容性

5、DBLE Release Notes

 

1、DBLE 項目介紹

DBLE 是企業級開源分佈式中間件，江湖人送外號 「MyCat Plus」；以其簡單穩定，持續維護，良好的社區環境和廣大的羣衆基礎獲得了社區的大力支持。

• DBLE 官方項目：https://github.com/actiontech/dble

如對源碼有興趣或者須要定製的功能的能夠經過源碼編譯安裝。

• DBLE 官方文檔：https://actiontech.github.io/dble-docs-cn

能夠詳細瞭解 DBLE 的背景和應用場景，本文未涉及到的細節均可在官方文檔得到。

• DBLE 下載地址：https://github.com/actiontech/dble/releases

[點擊學習 DBLE 公開課，Mycat 用戶更快上手哦！]

Tips：建議下載最新的 Releases 版本，下載 tar 壓縮包便可，若有源碼編譯需求的，能夠下載源碼包。

 

2、版本概況

距上一次 4 月 22 日【發版（2.19.03.0）】已有兩個多月，DBLE 社區又迎來了新版本的更新。

最新的 Release Notes 請參考：https://github.com/actiontech/dble/releases

新增 7 個特性，修復了 36 缺陷；

//劃重點

• 感謝 Github 用戶提供的優質 issue ，還有 QQ 羣提供的有效反饋的朋友

• issue 反饋質量不斷提升，保證了快速響應修復

• 發版頻率在穩定後會下降到兩個月一次

3、新特性

本次重點功能更新主要增長以下幾點：

• 支持 MySQL 8.0（alpha特性）

• 對存儲過程 hint 的完整支持 支持自定義告警接口（alpha特性）

• 優化最大鏈接數的默認值修改方式

• 更便捷的配置模板

 

4、升級兼容性

新版 DBLE 徹底兼容以往功能。

此次的更新離不開 DBLE 社區愛好者們的熱情支持，是大家的試用實踐使得 DBLE 功能越加穩定和成熟。

將來 DBLE 社區將繼續積極地推進 DBLE 的開源，讓更多的 MySQL 用戶可以使用到免費好用的分佈式中間件。

 

5、DBLE Release Notes

Features:

• Change the default max size of frontend connection for each user #1218

• Support MySQL8.0's default authentication plugin named 'caching_sha2_password' #1134

• Split Origin Merge to Merge And MERGE_AND_ORDER for Explain Plan  #1139

• Optimize global sequence generated by distributed timestamp #1138

• Improve dble's config template #1078

• The error messages should be more meaningful when dble instances are doing DDL simultaneously in one cluster #1105

• Support Stored procedure when connection enabled multiple statements

• Define alarm interface for developers to customize

Bug-fixes: 

• An error occurred while using Alibaba Cloud slb load balancing #1172

• Unknown pStmtId error when closing a prepared-statement that statement is the same as another in one connection #1236

• Backend conns will be closed when executing 'log @@limit=0,5000' in dble managed port #1220

• The network interrupt between dble and MySQL node before XA commit, the transaction lock in MySQL will always exist #1084

• Load data incorrect when the text contains a row with all null columns #1047

• SqlJob may finish more than once, and cause other problem #1231

• FetchStoreNodeOfChildTableHandler can cause serverConnection hang & leak of MySQL connection #1180

• NPE when using global sequence generated by MySQL-offset-step #1227

• MultiNodeQueryHandler#errorResponse add only one connection to errConnection list #1166, thanks @tankilo

• DateNode Idle Check Thread failed to fill empty dataSource when dataHost's minCon is less than database size, thanks @tankilo

• When MultiNodeQueryHandler send multiple SQL statements to MySQL, if the middle part failed to execute, frontend session will hang #1164, thanks @tankilo

• When complex cross join contained in an XA-transaction, the statement commit can't return #1116, thanks @kaikai2000

• multinode statement hang when setting statement error before executing

• Fail to recover XA Transaction on startup when XA log is not flushed and the server is down #1192

• Xa transaction commit failed due to network exception and could not be recovered by restarting dble #1113

• Even if the transaction is successfully restored, the state of the XA transaction in XA-log will always fail #1213

• Sending a statement to an uncreated physical database can cause thread safety problem #1144

• dble hang while inserting values into sharding table after executing "lock tables ... write" #1203

• For sharding tables(the two tables have the ER relationship), now "left join" got the result from only one dataNode #1197

• Load data will cause an exception when the column content only has one '"' at the beginning #1182, thanks @ssxlulu

• When implicit XA transaction fails to commit and is automatically rollbacked, the real error should be returned to the user instead of OK packet #1170, thanks @tankilo

• `Load data` execution result error when the load data file is empty #1198

• XA Transaction failed to commit due to the previous one's remaining error message((XACommitNodesHandler)MultiNodeHandler#isFailed) #1156, thanks @tankilo

• DDL lock can't be released when the server connection is abnormally closed #1168

• when running Sysbench OLTP test, XA transaction can't restore correctly after restarting dble #1114, thanks @kaikai2000

• It is recommended that `ZK` allow both uppercase and lowercase in the file of sequence_distributed_conf.properties #1162

• if where filter‘s length of complex query lager than 255, dble may return error #1120

• load data for a table using global sequence can not generate sequence column #1048

• Global sequence error when generated by distributed timestamps #1153

• show @@binlog.status query failed if all logic databases corresponding physical one's not created #1088

• Some of the SQL Method params in a complex query must be uppercase #1132

• Need to optimize, when starting dble, the configuration does not include the tables involved in the view #1100

• SQL returns an error, after the MySQL node disconnects during DDL execution #1119

• `Select query` to get results from multiple nodes may lead to thread safety problem #1147

• Error when select * from sharding\_2\_t1 a right join sharding\_4\_t1 b on a.id=b.ID where a.id >0 and a.id <4 #1142

• manager cmd "create database" error when connecting to dble with JDBC #1245

 

點擊連接，查看完整的 DBLE Release Notes：https://github.com/actiontech/dble/releases