更新 transaction stable table： 如果是 prepared 消息记，通过 TransactionStateService 服 务将消息加到存储事务状态的表格 tranStateTable 的文件中；如果是 commitType 和 rollbackType 消息， 修改事物状态表格 tranStateTable 中的消息状态。 记 录 Transaction Redo 查询消息，根据 commitLogOffset 和 msgSize 到 commitlog 查找消息 向 Producder 发起请求,请求 code 类型为 CHECK_TRANSACTION_STATE，producer 的 DefaultMQProducerImpl. checkTransactionState()方法来处理 broker 定时回调的请求， 这里构 建 一 个 时间点重新生成 redolog， 重新分发 消息 DispatchRequest, 分发消息到位置信息到 ConsumeQueue 更新 Transaction State Table 记录 Transaction Redo Log 删除事物状态表 tranStateTable 通过 RedoLog 全量恢复 StateTable 重头扫描 RedoLog，

CC需要幂等，能够⽀支持重试 5. 如果CC重试不不成功/超时，需要⼿手⼯工⼲干预 Apache RocketMQ 消息事务 Send a message first or execute local transaction first ? Member service Account service Send message Receive message 先执⾏行行本地事务还是先发送消息？ prepareMsg commitMsg rollbackMsg checkMsg TransactionMsgCheckService Bridge OP Msg User Side Transaction Service Part Storage Part 事务消息存储设计 Half Topic: prepare message TransactionMessageCheckService Service TxCoordinator 3 store TxQue Master Broker TxEvent Commit/Rollback Global Transaction ID Branch Transaction ID 1 RMQ Producer 2 CallbackListener 3 TxMessageProcessor begin begin begin begin

example: OMS Producer & OMS Pull consumer, OMS Push Consumer - Transaction example: send transactional message and implement transaction listener interface - Test for parallel producing & consuming examples with rocketmq queue(order, broadcast, schedule, batch, filter, logappender, openmessaging, transaction). Research about rocketmq multi-replica algorithms(based on DLedger). Download, test&run OpenMessaging RocketMQ examples : Pub/sub, Broadcast, Schedule, Batch, Filter, Logappender, OpenMessaging, Transaction -Discuss with mentor & community 1 June - 15 June 2 week - Checkpoint-Kicks tart - Divide

Offset = 4 Offset = 5 Offset = 6 Offset = 7 Offset = 8 Offset = N Commit Log Transaction State Table Transaction Redo Log 7.8 发送消息负载均衡 TOPIC_A Producer Roundbin方式，轮询 发送消息 7-5 发送消息 Rebalance CORBA Notification Service Specification 1.1 http://www.omg.org/spec/NOT/1.1/PDF  Distributed Transaction Processing: The XA Specification http://pubs.opengroup.org/onlinepubs/009680699/toc.pdf  RocketMQ

specification OpenMessaging specification Low Latency Message Trace MQTT/REST Proxy Relay Service Transaction Message Kafka Service Apache RocketMQ SDK(Java/C++/.Net/PHP/Go) | Console | JMS | HTTP |

specification OpenMessaging specification Low Latency Message Trace MQTT/REST Proxy Relay Service Transaction Message Kafka Service Apache RocketMQ SDK(Java/C++/.Net/PHP/Go) | Console | JMS | HTTP |