memcached
Cache everything that is expensive to compute/fetch
UDFs (user defined functions) 把memcached集成到MySQL中去
用途
memcached 可以用来缓存key:value，也可以用来缓存key:file
BUILD & INSTALL
翻了很久，没有发现Memcached有官方文档，莫非它真的简单到文档都是多余的？
首先，Memcached是使用LibEvnet库来实现异步IO的，先装LibEvent先
tar -zxvf libevent-1.4.13-stable.tar.gz
cd libevent-1.4.13-stable
./configure #将会装在/usr/local/lib中，参见./configure --help
make
make install #可以用ldconfig使Lib生效
tar -zxvf memcached-1.4.5.tar.gz
cd memcached-1.4.5
./configure #将会在/usr/local/lib中寻找libevent，将会装在/usr/local/lib中
make
make install
TEST
memcached -d -m 128 -p 11211 -u daemon # 参见man memcached
printf "set abc 0 0 5/r/n12345/r/n" | nc localhost 11211
printf "get abc/r/n" | nc localhost 11211
printf 'stats/r/n" | nc localhost 11211