Memcached是一套分布式的高速缓存系统，用于提升网站访问速度，尤其对于一些大型的、需要频繁访问数据库的网站，访问速度提升效果十分显著。

1.安装memcached
yum install memcached
yum install libmemcached
netstat -ntpl
systemctl status memcached
systemctl start memcached
netstat -ntupl

2.配置memcached只监听127.0.0.1
vim /etc/sysconfig/memcached
PORT="11211"
USER="memcached"
MAXCONN="1024"
CACHESIZE="64"
OPTIONS="-l 127.0.0.1 -U 0“ # -U 0 不启用UDP监听

systemctl restart memcached
netstat -ntpl
systemctl status memcached

3.检查memcached运行，能看到很多信息
memstat --servers="127.0.0.1"

4.配置memcached启用sasl
vim /etc/sysconfig/memcached
PORT="11211"
USER="memcached"
MAXCONN="1024"
CACHESIZE="64"
OPTIONS="-l 127.0.0.1 -U 0 -S -vv"

systemctl restart memcached
netstat -ntpl
memstat --servers="127.0.0.1"
echo $?

5.安装cyrus SASL库
yum install cyrus-sasl-devel cyrus-sasl-plain

6.配置sasl
vim /etc/sasl2/memcached.conf
mech_list: plain
log_level: 5
sasldb_path: /etc/sasl2/memcached-sasldb2

cat /etc/sasl2/memcached.conf
saslpasswd2 -a memcached -c -f /etc/sasl2/memcached-sasldb2 zeng
chown memcached:memcached /etc/sasl2/memcached-sasldb2
systemctl restart memcached
netstat -ntpl
memstat --servers="127.0.0.1"
echo $?
memstat --servers="127.0.0.1" --username=zeng --password=redhat