Programmer Think

MQ related concepts What is mq Message queue is literally a queue. First in, first out, only messages are stored. It is also a cross process communication mechanism for upstream and downstream message delivery. In the Internet architecture, mq is a common upstream and downstream "logical decoupling + physical decoupling" message ...

1, Message queue In a computer, a message is the data sent by one program to another, and a queue (a data structure) is a container. Everything stored in it is put in first and taken out first. Therefore, message queue is a container that temporarily saves messages during message transmission. The use of queues can avoid the disadvantage t ...

01 expiration time TTL The expiration time TTL indicates that the expected time can be set for the message, and within this time, it can be received and obtained by the consumer; After that, the message will be deleted automatically. RabbitMQ can set TTL for messages and queues. At present, there are two methods to set. The first method i ...

1. Middleware Middleware is the software between operating system and application program. Some people think it should be a part of operating system. When using middleware, people often integrate a group of middleware to form a platform (including development platform and operation platform), but there must be a communication middleware ...

Project scenario: As I know, the project we are working on now has many external interfaces for the agent to call, but the response of some interfaces is not returned in real time. At this time, we need to respond to the agent by calling back the interface. During this period, other situations such as network instability may occur, resulting i ...

After the Producer sends a message, various accidents may occur in the process of message delivery, resulting in the Consumer being unable to receive the message correctly. RabbitMQ has also introduced some solutions to deal with this situation. 1. Message reliability delivery After the Producer sends a message, it will be delivered through t ...

1. Basic concepts AMQP protocol: Advanced message queuing protocol, a network protocol for asynchronous message transmission between processes. rabbitmq is developed based on AMQP protocol General workflow: Publisher - > exchange - > queue - > consumer Broker: agent, consisting of Exchange and Queue The process of connecting produce ...

1-1 overview of message queuing 1. Queue From v 2. Message queue Message refers to the data transmitted between applications. Messages can be very simple, such as text strings and JSON, or complex, such as embedded objects. Message queue is a distributed message container that uses queue as the underlying storage data structure and ...

Release confirmation Release confirmation principle The producer sets the channel to confirm mode. Once the channel enters the confirm mode, all messages published on the channel will be assigned a unique ID (starting from 1). Once the message is delivered to all matching queues, the broker will send a confirmation to the producer (including ...

Definition: dead letter refers to messages that cannot be consumed. Dead letter queue is the queue for storing dead letters Source: Message TTL expired, maximum queue length reached, message rejected actual combat One producer and two consumers (C1 and C2), and the producer passes normal of direct type_ Exchange (the bindingKey is zh ...