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What is the role of Pub/Sub in Redis? I believe many inexperienced people don't know what to do about it. Therefore, this paper summarizes the causes and solutions of the problem. Through this article, I hope you can solve this problem.

Redis publishes commands related to the subscription model.

PSUBSCRIBE

Earliest available version: 2.0.0

Time complexity: O (N), N is the number of subscribed clients.

A client that subscribes to a given rule in the following forms:

H?llo subscribes to hello,hallo, hxllo, etc.

H*llo subscribes to hllo, heeeello, etc.

H [ae] subscribe to hello and hallo, but not to hillo

If you want to match verbatim, use\ to escape special characters.

PUBLISH

Earliest available version: 2.0.0

Time complexity: O (NumberM), N is the number of subscribed clients, M is the total number of subscriptions

Post a message to the specified channel.

PUBSUB

Earliest available version: 2.8.0

Time complexity: O (N), N is the number of active channels

This command is used to check the status of the Pub/Sub subsystem.

1PUBSUB CHANNELS [pattern]

List the currently active channels (with at least one subscriber). However, if you do not specify pattern, all channels are listed.

1PUBSUB NUMSUB [channel-1... Channel-N]

Returns the subscriber of the specified channel.

1PUBSUB NUMPAT

Returns the number of subscriptions for the specified pattern (executed using the PSUBSCRIBE command)

PUNSUBSCRIBE

Earliest available version: 2.0.0

Time complexity: O (NumberM), N is the number of subscriptions that have been subscribed by clients that match rules, and M is the total number of subscriptions to matching rules in the system

Usage: PUNSUBSCRIBE [pattern [pattern …]]

Unsubscribe all channels that match the rules, or unsubscribe all channels if no rules are specified.

SUBSCRIBE

Earliest available version: 2.0.0

Time complexity: O (N), N is the number of subscription channels

Subscribe to the specified channel to the client.

After reading the above, have you mastered the role of Pub/Sub in Redis? If you want to learn more skills or want to know more about it, you are welcome to follow the industry information channel, thank you for reading!

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