Programming VIP

Official address: https://rocketmq.apache.org/ Installation package download address: https://archive.apache.org/dist/rocketmq/ 1, Introduction to rocketmq RcoketMQ is a message oriented middleware with low latency, high reliability, scalability and ease of use. It has the following characteristics: Support publish / subscribe (Pub/Sub) a ...

Half(Prepare) Message Semi message is a special message type. Messages in this state cannot be consumed by consumers for the time being. When a transaction message is successfully delivered to the Broker, but the Broker does not receive the secondary confirmation sent by the Producer, the transaction message is in the "temporarily unavail ...

1, Basic sample Knowledge foreshadowing The steps of message sending are briefly listed as follows: Create a message producer and specify the producer group name Contact the Broker manager nameserver first. You need to specify the nameserver address Start producer. Create a message object and specify the Topic, Tag and message body send messag ...

1, Data cached by BrokerBroker mainly caches routing information, including producer table, consumer table, consumerGroup table and topic table. This information is managed in producer manager, ConsumerManager, SubscriptionGroupManager and TopicConfigManager.ProducerManager //producer list HashMap<String /* group name */, HashMap<Channel, ...

1, Remoting communication mechanism in RocketMQRocketMQ message queue cluster mainly includes NameServe, Broker(Master/Slave), Producer and consumer. The basic communication process is as follows:Register yourself with NameServer after the Broker is started; Then regularly report Topic routing information to NameServer every 30s;When sending a ...

We know that RocketMQ's NameServer is not strongly consistent, but ultimately consistent, that is, the client periodically obtains Broker information. If the Broker fails for a period of time, the client can't immediately sense it. How can RocketMQ achieve high availability of message sending? It can be expanded from the following three aspects ...

RocketMQ simple basic usage (III) In the last article, I demonstrated how to get started with RocketMQ. Next, I'll learn more about how to use RocketMQ through some simple examples. 1, General message RocketMQ provides three ways to send ordinary messages: reliable synchronous sending, reliable asynchronous sending and one-way sendi ...

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. Introduction to MQ 1. MQ purpose 1. Current limiting and peak clipping mq can temporarily store the excessive requests of the system so that the system can process them slowly later, so as to avoid the loss of requests or the collapse of the system. 2. Asynchronous decoupling The synchronous call between services is changed to MQ asynchronou ...

Stand alone installation Front work Hardware requirements: 64 bit Linux/Unix/Mac/Windows4G and above disk space Software requirements: 64 bit JDK above 1.8Maven 3.2.xGit Installation: 1. Download the installation package 4.9. 2 download address 2. Upload the downloaded package to Linux It can be uploaded through rz command. For ot ...