redis一个实例能存多少个key

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

Redis can handle up to 2^32 keys, and was tested in practice to handle at least 250 million keys per instance.

Every hash, list, set, and sorted set, can hold 2^32 elements.

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