Hello MQ

外观

ActiveMQ Classic 可靠性 ​

本页结论：Classic 的可靠性骨架是「persistent send 落盘确认 + commit 后删除 + Broker 端强制执行的重投策略」。重投策略由客户端经连接 URL 声明（jms.redeliveryPolicy.*）；毒消息耗尽后自动进默认共享死信 ActiveMQ.DLQ，无需任何 broker 配置。

生产端：持久与确认 ​

默认持久、同步确认。JMS producer.send(msg) 默认 PERSISTENT，阻塞直到 Broker 确认收到（持久消息已写 KahaDB）。返回即代表单节点写入成功——这是本仓库 status=confirmed 的含义。

事务发送。事务会话内一次 commit 原子发送多条消息；与消费侧事务同属 JMS 本地事务，Broker 内原子。

定时投递。属性 AMQ_SCHEDULED_DELAY=<毫秒> 让消息延迟可见，但需要 broker 开启 schedulerSupport=true（官方文档 E1；镜像默认 conf 未开启，使用前先确认配置）。

消费端：commit 即删除与崩溃窗口 ​

本仓库实验用 Session.SESSION_TRANSACTED 会话，处理顺序固定：

text
receive → 业务写库（sqlite 事务提交）→ session.commit()（确认并删除）

崩溃窗口与其它队列型 Broker 同构：

  • 业务提交前崩溃：消息未 commit，仍在队列 → 重投，业务侧靠幂等表拦截重复；
  • commit 后、下一轮前崩溃：无损失；
  • 业务提交后、commit 前崩溃：消息重投 → 幂等表命中 duplicate_skipped。这是「至少一次 + 幂等」的标准形态。

错误做法：AUTO_ACKNOWLEDGE 会话让客户端在回调返回时自动确认——业务失败即丢消息，生产禁用。

重投：redeliveryPolicy（客户端声明、Broker 执行） ​

重投策略不经 broker.xml，而是客户端经连接 URL 下发、由 Broker 端强制执行（本仓库 retry-dlq 实验实测）：

text
tcp://activemq:61616?jms.redeliveryPolicy.maximumRedeliveries=2&jms.redeliveryPolicy.initialRedeliveryDelay=1000
  • 计数口径：maximumRedeliveries 计「重投次数」，不含首次投递——设 2 实测共投递 3 次（与 Artemis max-delivery-attempts=3 对齐）；官方默认值为 6（E1：Redelivery Policy）。
  • 触发方式：消费者 session.rollback()（或断连、未 commit 关闭会话）；initialRedeliveryDelay 默认 1s，可配指数退避（默认关闭）。
  • 与 Artemis 的差异在配置位置（客户端 URL vs broker.xml address-setting），「服务端强制执行」的性质相同。

死信：默认共享 ActiveMQ.DLQ ​

  • 重投耗尽后消息自动转入默认死信队列 ActiveMQ.DLQ——无需任何 broker 配置（本仓库实测：dlq-consumer 从 ActiveMQ.DLQ 收到毒消息）；
  • ActiveMQ.DLQ 是全 broker 共享的：所有队列的毒消息混在一起，告警无法区分业务线。按目的地拆分专属 DLQ 用 destinationPolicy 的 individualDeadLetterStrategy（官方文档 E1：Message Redelivery and DLQ Handling）；
  • 非持久消息默认不进 DLQ（processNonPersistent 默认关闭，耗尽/过期直接丢弃）——依赖 DLQ 兜底就必须发送 persistent 消息。

实验与观察点 ​

  • activemq-classic basic（L1）：persistent 确认 → 业务提交 → session.commit() → 队列深度归零，验证 commit 即删除与幂等落库。
  • activemq-classic retry-dlq（L2）：毒消息 rollback 后共投递 3 次（poisonMaxAttempt=3），耗尽进 ActiveMQ.DLQ（dlqReceived=1）。
activemq-classic / retry-dlqbash demos/activemq-classic/retry-dlq/run.sh
assert.out.txt
PASS confirmed: 2
PASS okReceived: 1
PASS businessCommitted: 1
PASS business_rows: 1
PASS poisonAttempts: true
PASS poisonMaxAttempt: 3
PASS dlqReceived: 1
PASS dlqIsPoison: 1
RESULT: all assertions passed
consumer.out.txt
SLF4J(W): No SLF4J providers were found.
SLF4J(W): Defaulting to no-operation (NOP) logger implementation
SLF4J(W): See https://www.slf4j.org/codes.html#noProviders for further details.
[consumer] timestamp=2026-08-20T17:03:37.001451968Z level=INFO service=order-service product=activemq-classic lab=retry-dlq destination=orders-retry consumer=consumer-1 status=subscribed
[consumer] timestamp=2026-08-20T17:03:37.161612084Z level=INFO service=order-service product=activemq-classic lab=retry-dlq messageId=01JMQ000000000000000000001 eventType=order.created schemaVersion=1 aggregateId=order-1001 traceId=00000000000000000000000000000001 correlationId=order-1001 destination=orders-retry seq=1 consumer=consumer-1 attempt=1 redelivered=false deliveryDelayMs=1232 status=received
[consumer] timestamp=2026-08-20T17:03:37.173111826Z level=INFO service=order-service product=activemq-classic lab=retry-dlq messageId=01JMQ000000000000000000001 eventType=order.created schemaVersion=1 aggregateId=order-1001 traceId=00000000000000000000000000000001 correlationId=order-1001 destination=orders-retry consumer=consumer-1 attempt=1 status=business_committed
[consumer] timestamp=2026-08-20T17:03:37.182671884Z level=INFO service=order-service product=activemq-classic lab=retry-dlq messageId=01JMQ00000000000000000000P eventType=order.created schemaVersion=1 aggregateId=order-poison traceId=0000000000000000000000000000000P correlationId=order-poison destination=orders-retry seq=2 consumer=consumer-1 attempt=1 redelivered=false deliveryDelayMs=1227 status=received
[consumer] timestamp=2026-08-20T17:03:37.182799673Z level=INFO service=order-service product=activemq-classic lab=retry-dlq messageId=01JMQ00000000000000000000P eventType=order.created schemaVersion=1 aggregateId=order-poison traceId=0000000000000000000000000000000P correlationId=order-poison destination=orders-retry consumer=consumer-1 attempt=1 status=consume_failed
[consumer] timestamp=2026-08-20T17:03:38.190558913Z level=INFO service=order-service product=activemq-classic lab=retry-dlq messageId=01JMQ00000000000000000000P eventType=order.created schemaVersion=1 aggregateId=order-poison traceId=0000000000000000000000000000000P correlationId=order-poison destination=orders-retry seq=2 consumer=consumer-1 attempt=2 redelivered=true deliveryDelayMs=2235 status=received
[consumer] timestamp=2026-08-20T17:03:38.190748727Z level=INFO service=order-service product=activemq-classic lab=retry-dlq messageId=01JMQ00000000000000000000P eventType=order.created schemaVersion=1 aggregateId=order-poison traceId=0000000000000000000000000000000P correlationId=order-poison destination=orders-retry consumer=consumer-1 attempt=2 status=consume_failed
[consumer] timestamp=2026-08-20T17:03:39.195644166Z level=INFO service=order-service product=activemq-classic lab=retry-dlq messageId=01JMQ00000000000000000000P eventType=order.created schemaVersion=1 aggregateId=order-poison traceId=0000000000000000000000000000000P correlationId=order-poison destination=orders-retry seq=2 consumer=consumer-1 attempt=3 redelivered=true deliveryDelayMs=3240 status=received
[consumer] timestamp=2026-08-20T17:03:39.195835373Z level=INFO service=order-service product=activemq-classic lab=retry-dlq messageId=01JMQ00000000000000000000P eventType=order.created schemaVersion=1 aggregateId=order-poison traceId=0000000000000000000000000000000P correlationId=order-poison destination=orders-retry consumer=consumer-1 attempt=3 status=consume_failed
[consumer] timestamp=2026-08-20T17:03:39.218483126Z level=INFO service=order-service product=activemq-classic lab=retry-dlq destination=orders-retry consumer=consumer-1 received=4 poisonMaxAttempt=3 status=done
dlq-consumer.out.txt
SLF4J(W): No SLF4J providers were found.
SLF4J(W): Defaulting to no-operation (NOP) logger implementation
SLF4J(W): See https://www.slf4j.org/codes.html#noProviders for further details.
[consumer] timestamp=2026-08-20T17:03:40.863180071Z level=INFO service=order-service product=activemq-classic lab=retry-dlq destination=ActiveMQ.DLQ consumer=dlq-inspect status=subscribed
[consumer] timestamp=2026-08-20T17:03:41.028535995Z level=INFO service=order-service product=activemq-classic lab=retry-dlq messageId=01JMQ00000000000000000000P eventType=order.created schemaVersion=1 aggregateId=order-poison traceId=0000000000000000000000000000000P correlationId=order-poison destination=ActiveMQ.DLQ seq=2 consumer=dlq-inspect attempt=1 redelivered=false deliveryDelayMs=5073 status=received
[consumer] timestamp=2026-08-20T17:03:41.028738584Z level=INFO service=order-service product=activemq-classic lab=retry-dlq messageId=01JMQ00000000000000000000P eventType=order.created schemaVersion=1 aggregateId=order-poison traceId=0000000000000000000000000000000P correlationId=order-poison destination=ActiveMQ.DLQ consumer=dlq-inspect attempt=1 status=inspected
[consumer] timestamp=2026-08-20T17:03:41.034928590Z level=INFO service=order-service product=activemq-classic lab=retry-dlq destination=ActiveMQ.DLQ consumer=dlq-inspect received=1 poisonMaxAttempt=1 status=done
inspect-db.out.txt
SLF4J(W): No SLF4J providers were found.
SLF4J(W): Defaulting to no-operation (NOP) logger implementation
SLF4J(W): See https://www.slf4j.org/codes.html#noProviders for further details.
[inspect] timestamp=2026-08-20T17:03:39.909341182Z level=INFO service=order-service product=activemq-classic lab=retry-dlq business_rows=1 processed_rows=1 status=snapshot
producer.out.txt
SLF4J(W): No SLF4J providers were found.
SLF4J(W): Defaulting to no-operation (NOP) logger implementation
SLF4J(W): See https://www.slf4j.org/codes.html#noProviders for further details.
[producer] timestamp=2026-08-20T17:03:35.952148325Z level=INFO service=order-service product=activemq-classic lab=retry-dlq messageId=01JMQ000000000000000000001 eventType=order.created schemaVersion=1 aggregateId=order-1001 traceId=00000000000000000000000000000001 correlationId=order-1001 destination=orders-retry seq=1 brokerMessageId=ID:b4eafb2073b0-41463-1787245415464-1:1:1:1:1 durationMs=22 status=confirmed
[producer] timestamp=2026-08-20T17:03:35.959021404Z level=INFO service=order-service product=activemq-classic lab=retry-dlq messageId=01JMQ00000000000000000000P eventType=order.created schemaVersion=1 aggregateId=order-poison traceId=0000000000000000000000000000000P correlationId=order-poison destination=orders-retry seq=2 brokerMessageId=ID:b4eafb2073b0-41463-1787245415464-1:1:1:1:2 durationMs=3 status=confirmed
[producer] timestamp=2026-08-20T17:03:35.959589695Z level=INFO service=order-service product=activemq-classic lab=retry-dlq destination=orders-retry sent=2 status=done

运行：bash demos/activemq-classic/basic/run.sh、bash demos/activemq-classic/retry-dlq/run.sh。

边界 ​

  • 队列无消费位点：不存在「跳过坏消息继续」的位点操作，毒消息必须靠重试上限 + DLQ 清出。
  • 重投计数随消息累计（JMSXDeliveryCount 可见当前是第几次投递）。
  • AMQP/STOMP/MQTT 协议接入时，确认映射为各自的 ack/disposition，语义一致但 API 不同。

以统一实验验证消息系统语义边界

MIT License