The Redis server is not running: Make sure the Redis server is successfully started before attempting to connect to it.
There is a port error on the Redis server: By default, the Redis server listens on port 6379. If the port number has been changed in the configuration file, you will need to connect using the updated port number.
Network connection issue: The Redis server may be experiencing problems with its network connection, such as network failures or firewall blocking connections.
Authentication failed: If the Redis server has password authentication enabled, the correct authentication password must be provided during connection.
Maximum connection limit: The Redis server may have reached its maximum connection limit and is unable to accept any new connections.
Configuration file error: There may be errors in the Redis server’s configuration file, preventing the connection.
There may be errors in the client code when connecting to Redis, such as incorrect connection parameters or a too short connection timeout.
Insufficient hardware resources: The Redis server may be unable to connect due to a lack of hardware resources.
Other unknown reasons: There could also be other unknown factors, such as operating system issues or network environment problems.
