Here’s a quick way to test your new memcached setup. At first it’s a bit confusing to understand that memcache has no knowledge of what keys it stores, just whether or not it has a particular key. Unlike relational databases, you can’t query memcache and get all of the values it has. You have to know the key that you want to fetch before you ask memcache about it. Let’s ask it the value for the key foo:

telnet memcacheserver 11211
Trying 10.131.215.181...
Connected to 10.131.215.181
Escape character is '^]'.
get foo
END

It returns nothing, so it doesn’t have any value for that key. The key foo is unset. Let’s set it:

set foo 0 0 3
bar
STORED

When you set a key like this, follow the syntax “set <keyname> <flag> <ttl> <storebytes>”. In this case our key is foo, we have no important flags (0), there is no expiration of the key value pair (0), and the data we are about to store is 3 bytes (aka 3 characters). Let’s fetch it now:

get foo
VALUE foo 0 3
bar
END

It returns the value of key foo as bar. Now delete it:

delete foo
DELETED

Now another, this time the key is “foobar”, and the data is a 12 byte string “barbarbarbar”:

set foobar 0 0 12
barbarbarbar
STORED
get foobar
VALUE foobar 0 12
barbarbarbar
END
delete foobar
DELETED
^]
telnet> close
Connection closed.