Redis查看存储空间一览无余（redis 查看存储大小）

Redis: A Comprehensive Guide to Monitor Storage

Redis is an open source, in-memory data structure store. It is often used as a database, cache, and message broker. One crucial aspect of using Redis is monitoring the storage space to ensure that your data fits into memory and to avoid expensive delays.

In this guide, we will explore the various ways to monitor storage space using Redis.

1. Redis Memory Usage Command

The Redis Memory Usage command (MEMORY USAGE) returns the total amount of memory used by Redis to store all its data. It also provides a breakdown of memory usage by key, type, and encoding. You can run this command in the Redis CLI or use one of the Redis client libraries such as Redis-Py to execute it programmatically.

Here’s an example of how to use the Redis Memory Usage command:

$ redis-cli
127.0.0.1:6379> MEMORY USAGE mykey
(integer) 36

2. Redis Info Command

The Redis Info command (INFO) provides a comprehensive overview of the Redis instance, including memory usage, number of keys, clients, and more. You can use this command to monitor the memory usage of Redis and detect any performance bottlenecks.

Here’s an example of how to use the Redis Info command:

$ redis-cli
127.0.0.1:6379> INFO memory
# Memory
used_memory:1187352
used_memory_human:1.13M
used_memory_rss:5683200
...

3. Redis Configuration Parameters

Redis provides several configuration parameters to optimize memory usage and monitor storage space. These parameters include maxmemory, maxmemory-policy, and maxmemory-samples. You can configure these parameters in the Redis configuration file or using the CONFIG SET command.

Here’s an example of how to configure the maxmemory parameter in the Redis configuration file:

maxmemory 2gb

4. Redis RDB and AOF Persistence Modes

Redis provides two persistence modes to save data to disk: RDB and AOF. RDB is a point-in-time snapshot of the Redis data set, while AOF logs all write operations to a file. You can use these persistence modes to recover data in case of a Redis server flure and to monitor storage space usage.

Here’s an example of how to configure the RDB persistence mode in the Redis configuration file:

save 900 1
save 300 10
save 60 10000

Conclusion

Monitoring Redis storage space is vital for ensuring optimal performance and avoiding costly downtime. By combining the Redis Memory Usage command, Redis Info command, configuration parameters, and persistence modes, you can build a comprehensive monitoring system to keep track of your Redis instance’s storage space. With these tools at your disposal, you can confidently manage your Redis instance while benefiting from the power and speed of in-memory data storage.