How to Clear Redis Cache

Redis is a free, open-source, in-memory data store used by millions of developers as a database, cache, streaming engine, and message broker.

In this tutorial, you will learn how to clear the Redis cache by removing all the keys in a given Redis database using the CLI utility.

Redis Clear Cache with the Redis CLI

Redis provides a CLI interface that allows us to interact with the Redis server using raw commands in a terminal session.

we can use the Redis CLI commands to remove all the keys from a single or all databases in the cluster.

Redis Delete All Keys From Specific Database

In Redis, we can use the flushdb command to remove all the keys from a specific database. The command syntax is as shown:

redis-cli flushdb

Calling the flushdb command without any arguments will remove all the keys from the currently selected database.

To remove all the data stored in a target Redis database, use the -n option; the syntax is as shown:

 bash redis-cli -n [database_index] flushdb

Where the database_index is the target database ranging from 0 to 16.

Since Redis version 4.0+, we can delete keys from a given database in the background without blocking the server. This is possible using the asynchronous option specified using the ASYNC parameter.

Command syntax:

redis-cli FLUSHDB ASYNC
redis-cli -n <database_index> FLUSHDB ASYNC

Redis Delete All Keys

To delete all the keys from the Redis cluster (across all databases), we can use the FLUSHALL command as shown:

redis-cli flushall

To operate asynchronously, run the following:

redis-cli flushall async

Conclusion

This tutorial shows how to remove all the keys from a given database. You also learned how to clear the Redis cache by removing all the data across the Redis databases.