Improve connection speed by running fewer commands #2850
Description
Today, connecting to a Redis instance, involves running multiple commands, and parsing the response repeatedly, this includes usage such as setinfo, which itself is run twice. The example below illustrates, that it's possible to pass all connection configuration information within a pipeline. In turn, the HELLO call returns the version of Redis, which could perhaps be used later for other things.
This is marked as good-first-issue not because it's necessarily easy to implement, inasmuch as it's a good entrypoint, to learning how connections to redis occur.
127.0.0.1:6379> multi OK 127.0.0.1:6379(TX)> auth bob smurf QUEUED 127.0.0.1:6379(TX)> select 5 QUEUED 127.0.0.1:6379[5](TX)> hello 3 QUEUED 127.0.0.1:6379[5](TX)> client setinfo lib-name predis QUEUED 127.0.0.1:6379[5](TX)> client setinfo lib-ver 55.5.0 QUEUED 127.0.0.1:6379[5](TX)> client tracking on optin QUEUED 127.0.0.1:6379[5](TX)> CLIENT caching yes QUEUED 127.0.0.1:6379[5](TX)> exec 1) OK 2) OK 3) 1# "server" => "redis" 2# "version" => "7.2.3" 3# "proto" => (integer) 3 4# "id" => (integer) 26 5# "mode" => "standalone" 6# "role" => "master" 7# "modules" => (empty array) 4) OK 5) OK 6) OK 7) OK 127.0.0.1:6379[5]>