Multithreading SpringBoot:手动确认多条AMQP消息
只有在成功处理和存储多条消息之后,我才需要在rabbit侦听器中手动确认这些消息。使用的Spring引导配置如下所示Multithreading SpringBoot:手动确认多条AMQP消息,multithreading,spring-boot,rabbitmq,spring-amqp,spring-rabbit,Multithreading,Spring Boot,Rabbitmq,Spring Amqp,Spring Rabbit,只有在成功处理和存储多条消息之后,我才需要在rabbit侦听器中手动确认这些消息。使用的Spring引导配置如下所示 listener: concurrency: 2 max-concurrency: 20 acknowledge-mode: manual prefetch: 30 class DeliveredMesssagingEvent { int deliveryTag Event event } class ChannelData { Channel c
listener:
concurrency: 2
max-concurrency: 20
acknowledge-mode: manual
prefetch: 30
class DeliveredMesssagingEvent {
int deliveryTag
Event event
}
class ChannelData {
Channel channel
List<DeliveredEvent> deliveredEvents = new ArrayList<>()
ChannelData(Channel channel) {
this.channel = channel
}
void addEvent(long tag, Event event) {
deliveredEvents.add(new DeliveredEvent(deliveryTag: tag, event: event))
}
}
消息应一次存储20个批次。只有在成功存储它们时,才应发送多个ack。还有一个与存储机制相关联的超时,它应该在20秒后存储消息,即使没有20条消息。目前,我有以下代码
@Slf4j
@Component
class EventListener {
@Autowired
private EventsStorage eventsStorage
private ConcurrentMap<Integer, ChannelData> channelEvents = new ConcurrentHashMap<>()
@RabbitListener(queues = 'event-queue')
void processEvent(@Payload Event event, Channel channel, @Header(DELIVERY_TAG) long tag) {
log.debug("Event received for channel $channel.channelNumber")
channelEvents.compute(channel.channelNumber, { k, channelData -> addEventAndStoreIfNeeded(channel, event, tag, channelData) })
}
private ChannelData addEventAndStoreIfNeeded(Channel channel, Event event, long tag, ChannelData channelData) {
if (channelData) {
channelData.addEvent(tag, event)
if (channelData.getDeliveredEvents().size() >= batchSize) {
storeAndAckChannelEvents(channel.channelNumber)
}
return channelData
} else {
ChannelData newChannelData = new ChannelData(channel)
newChannelData.addEvent(tag, event)
return newChannelData
}
}
void storeAndAckChannelEvents(Integer channelNumber) {
channelEvents.compute(channelNumber, { k, channelData ->
List<DeliveredEvent> deliveredEvents = channelData.deliveredEvents
if (!deliveredEvents.isEmpty()) {
def events = deliveredEvents.stream()
.map({ DeliveredEvent deliveredEvent -> deliveredEvent.event })
.collect(Collectors.toList())
eventsStorage.store(events)
long lastDeliveryTag = deliveredEvents.get(deliveredEvents.size() - 1).deliveryTag
channelData.channel.basicAck(lastDeliveryTag, true)
deliveredEvents.clear()
}
})
}
@Scheduled(fixedRate = 20000L)
void storeMessagingEvents() {
channelEvents.forEach({ k, channelData -> storeAndAckChannelEvents(channelData) })
}
}
使用的频道是com.rabbitmq.client.Channel
。关于此接口状态:
通道实例不能在线程之间共享。应用程序应该更喜欢每个线程使用一个通道,而不是跨多个线程共享同一个通道
所以,我的做法正好相反,在调度程序
和SimpleMessageListenerContainer
工作线程之间共享通道。我的应用程序的输出如下所示:
[SimpleAsyncTaskExecutor-3] DEBUG EventListener - Event received for channel 2
[SimpleAsyncTaskExecutor-4] DEBUG EventListener - Event received for channel 3
[SimpleAsyncTaskExecutor-5] DEBUG EventListener - Event received for channel 1
[SimpleAsyncTaskExecutor-1] DEBUG EventListener - Event received for channel 5
[SimpleAsyncTaskExecutor-2] DEBUG EventListener - Event received for channel 4
[SimpleAsyncTaskExecutor-3] DEBUG EventListener - Event received for channel 2
[SimpleAsyncTaskExecutor-1] DEBUG EventListener - Event received for channel 5
[SimpleAsyncTaskExecutor-2] DEBUG EventListener - Event received for channel 4
[SimpleAsyncTaskExecutor-3] DEBUG EventListener - Event received for channel 2
[pool-4-thread-1] DEBUG EventListener - Storing channel 5 events
[pool-4-thread-1] DEBUG EventListener - Storing channel 2 events
...
SimpleMessageListenerContainer
工作线程有自己的通道,不会随时间而改变
考虑到我同步了调度程序
和SimpleMessageListenerContainer
工作线程,是否有人看到此代码不具有线程安全性的原因
在Spring boot中是否有其他方法可以尝试手动确认多条消息?只要同步线程,就可以了
但是,请记住,如果连接丢失,您将获得一个新的使用者,并且您的同步线程将具有过时的数据(未确认的消息将被重新传递)
但是,您也可以使用
当使用者线程空闲了一段时间后,事件将在同一侦听器线程上发布,因此您可以在那里执行定时确认,而不必担心同步问题
您还可以检测连接是否丢失