Redis - message publish and subscribe

Foreword

Redis publish-subscribe (pub/sub) is a message communication model: sender (pub) sends messages and subscribers (sub) receive messages.
Redis clients can subscribe to any number of channels!

First, the implementation method:

①Commands:
These commands are widely used to build instant messaging applications, such as online chat rooms (chatroom) and real-time broadcasting, real-time reminders, etc.

②Implementation of publish and subscribe:
1. Subscriber:

127.0.0.1:6379> pingPONG127.0.0.1:6379> SUBSCRIBE dingdada #Subscribe to the channel named dingdadaReading messages... (press Ctrl-C to quit)1) "subscribe"2) "dingdada"3) (integer) 1#Waiting for push information1) "message" #message2) "dingdada" #The message from which channel3) "hello world\xef\xbc\x81" # The specific content of the message1) "message"2) "dingdada"3) "my name is dyj\x81"

2. Sender:

127.0.0.1:6379> pingPONG127.0.0.1:6379> PUBLISH dingdada "hello world!" #Send message to dingdada channel(integer) 1127.0.0.1:6379> PUBLISH dingdada "my name is dyj" #Send message to dingdada channel(integer) 1

As shown in the picture:
Subscriber:

Sender:

③PSUBSCRIBE command: subscribe to the specified channel!

③PSUBSCRIBE command: subscribe to the specified channel!

④PUBLISH command: send a message to the specified channel!

PUBLISH + channel + message #Send information message to the specified channel channel

⑤PUNSUBSCRIBE command: unsubscribe!

#Instructs the client to unsubscribe from the specified mode, and exits all modes if no mode is provided.

⑥SUBSCRIBE: Subscription, same as above.Don't go into details!

⑦UNSUBSCRIBE: Unsubscribe, same as above, no details!

⑧Summary:

Pub/Sub literally means Publish and Subscribe. In Redis, you can set message publishing and message subscription for a certain key value. When a message is published on a key valueAfter that, all clients that subscribe to it will receive the corresponding message.The most obvious usage of this function is as a real-time messaging system, such as ordinary instant chat, group chat and other functions.