cannot store values into memcache

[Huang]

hello!
when i'm running PHP+memcache,but i cannot store values into memcache.
PHP version is 5.4.12
memcache version is 3.0.8

i set ini_set('display_errors', true); and error_reporting(E_ALL); then get

Notice: MemcachePool::set(): Server 127.0.0.1 (tcp 11211, udp 0) failed
with: Network timeout (0) in /data/swsg/test7/html/api/test/quiz_test.php
on line 10

and i try to use the "telnet 127.0.0.1 11211".

$ telnet 127.0.0.1 11211
Trying 127.0.0.1...
Connected to 127.0.0.1.
Escape character is '^]'.
stats

there's no any response...

do u have any ideas?

thks!