Replica Node in ClusterClient is never used when Redis Server does not support "COMMAND" command

[Decoydoll]

The replica node in the ClusterClient is never used for read only operation when redis server does not support "COMMAND" command. We suspect this because of this implementation which require the cmdInfo to be not nil in order to potentially use the replica node for read only operation. Otherwise, it will always use the master node. In our case, the cmdInfo is always nil because our Redis Server provider, Aiven, has confirmed that they restrict the COMMAND command giving us error ERR unknown command 'COMMAND'.

Expected Behavior

Replica node can be used for read only operation even when COMMAND command is not supported

Current Behavior

Replica node is not used for read only operation even when COMMAND command is not supported

Possible Solution

Provide an option for skipping the cmdInfo checking (?)