一个 Redis 实例最多可容纳键的数量是多少？

官方解释单例能处理key：2.5亿个，参考链接：https://redis.io/topics/faq ，以下是原话：

What is the maximum number of keys a single Redis instance can hold? and what is the max number of elements in a Hash, List, Set, Sorted Set?

Redis can handle up to 2³² keys, and was tested in practice to handle at least 250 million keys per instance.

Every hash, list, set, and sorted set, can hold 2³² elements.

In other words your limit is likely the available memory in your system.