First of all, the official statement of Redis is: "A String value can be at max 512 Megabytes in length." There are two problems with overly large keys and values: Redis is an in-memory database. If the key and value are too large, it will first cause memory fragmentation in the server. This will affect the efficiency of Redis's memory allocation, further leading to a decrease in memory usage. Keys and values ??with excessive capacity also have several effects: a. These overly large data require more time to transmit data; b. Excessively large data transmission may cause other requests to time out if A's response data is too large. , it may eat up the timeout of other requests.

As shown in the example below, if the response data of A is too large, it will eat up the timeout of other requests