no time set data ( linux )

amazingly fast method for setting data, be careful it contains
shell_exec with json_data.

so if you don't trust to data, i suggest you to sanitize it carefully.

some stats (on digitalocean vps - ubuntu 12.04 ):
50 set request with set method [ it using cURL ]=> 30sec
50 set requests with set_multi method [ it using fsocks ] => 12 sec
50 set requests with set_fast method [ it using cURL with shell exec /
parallel ] => 0.4 sec