Why Is "ERR unknown command" Displayed When I Access a DCS Redis Instance Through a Redis Client?

The possible causes are as follows:

1. The command is spelled incorrectly.

   As shown in the following figure, the error message is returned because the correct command for deleting a string should be del.

   

2. A command available in a higher Redis version is run in a lower Redis version.

   As shown in the following figure, the error message is returned because a stream command (available in Redis 5.0) is run in Redis 3.0.

   

3. Some commands are disabled.

   DCS Redis instance interfaces are fully compatible with the open-source Redis in terms of data access. However, for ease of use and security purposes, some operations cannot be initiated through Redis clients. For details about disabled commands, see Command Compatibility.