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1, Foreword When studying the consumption timeout of RocketMQ Consumer, which leads to repeated consumption, I suddenly thought of a thing: how does the Broker perceive the abnormal downtime and offline of the Consumer/Producer? And how can the remaining consumers quickly redo the load?, Originally, after sorting out the source code of Broker ...

1. The concept of dead letter queues _First, clarify this definition from the conceptual explanation. Dead faith, as its name implies, is a message that cannot be consumed. Literally, it means that producer delivers the message to broker or directly to queue. Consumerer takes the message out of queue for consumption, but sometimes some mes ...

5. Switch In the previous section, we created a work queue. We assume that behind the work queue, each task is delivered to exactly one consumer (work process). In this section, we will do something completely different - we will convey the message to multiple consumers. This mode is called publish / subscribe To illustrate this pattern, we w ...

preface Basic learning about RabbitMQ 1, What is RabbiMQ? RabbitMQ is a message oriented middleware: it accepts and forwards messages. You can regard it as an express site. When you want to send a package, you put your package in the express station, and the courier will eventually send your express to the recipient. According to t ...

Existing requirements: when the producer sends a new message to the message queue, the message queue should process it automatically according to the message, such as pushing the message to the consumer. Amazon SQS message queue itself does not support further processing when new messages arrive at the queue, but we can realize this requiremen ...

Publisher confirms is an extension of RabbitMQ to realize reliable publishing. When publisher confirmation is enabled on the channel, if the messages published by the client are asynchronously confirmed by the proxy, it means that they have been processed on the server. In this tutorial, we will use publisher confirms to ensure that published m ...

When we are developing or designing a website, we often encounter mass SMS, mass email, or send in station letters to all users of the system, or in the order system, we need to record a large number of logs. If our system is an e-commerce system, when designing rush buying and second kill activities, the server is high and distributed, and we ...

The consumer may report an error during message processing. How to reprocess the message? There are two solutions. Record the number of retries in redis or database. After the maximum number of retries is reached, the messages enter the dead letter queue or other queues, and then process these messages separately; Use the retry function i ...

Recently, readers have encountered a problem with Alipay: If an order is generated without payment for 30 minutes, it will be cancelled automatically. How can I do this? In fact, such delayed tasks are often required in development, such as Generate order 30 minutes unpaid, cancel automatically Send a text message to the user 60 seconds ...

Source version 4.8.0 Message sending source code entry The simplest message sending code DefaultMQProducer producer = new DefaultMQProducer("please_rename_unique_group_name"); producer.setNamesrvAddr("127.0.0.1:9876"); producer.start(); Message msg = new Message("TopicTest" /* Topic */, ...