最近在centos 7下面安装openstack进行测试。
安装到memcached这一步骤时启动服务后查看服务状态报错
系统内核版本：
[root@openstack ~]# uname -a
Linux openstack 3.10.0-514.16.1.el7.x86_64 #1 SMP Wed Apr 12 15:04:24 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux
启动memcached服务并查看状态
[root@openstack sysconfig]# systemctl restart memcached
[root@openstack sysconfig]# systemctl status memcached
● memcached.service - memcached daemon
Loaded: loaded (/usr/lib/systemd/system/memcached.service; enabled; vendor preset: disabled)
Active: Failed (Result: exit-code) since Mon 2017-04-24 13:36:10 CST; 8s ago
Process: 14143 ExecStart=/usr/bin/memcached -p ${PORT} -u ${USER} -m ${CACHESIZE} -c ${MAXCONN} $OPTIONS (code=exited,status=71)
Main PID: 14143 (code=exited,status=71)
Apr 24 13:36:10 openstack systemd[1]: Started memcached daemon.
Apr 24 13:36:10 openstack systemd[1]: Starting memcached daemon...
Apr 24 13:36:10 openstack memcached[14143]: Failed to listen on TCP port 11211: Address already in use
Apr 24 13:36:10 openstack systemd[1]: memcached.service: main process exited,code=exited,status=71/n/a
Apr 24 13:36:10 openstack systemd[1]: Unit memcached.service entered Failed state.
Apr 24 13:36:10 openstack systemd[1]: memcached.service Failed.
又返回去查看/etc/sysconfig/memcached配置文件
[root@openstack sysconfig]# more memcached
PORT="11211"
USER="memcached"
MAXCONN="1024"
CACHESIZE="64"
OPTIONS="-l 127.0.0.1,openstack"
这么配置发现不行，然后去搜了相关报错内容，根据报错信息，以为是端口被占用，通过netstat -antup命令并没有发现相关端口被占用
[root@openstack sysconfig]# netstat -antup
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 0.0.0.0:4369 0.0.0.0:* LISTEN 1/systemd
tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN 862/sshd
tcp 0 0 127.0.0.1:25 0.0.0.0:* LISTEN 1304/master
tcp 0 0 0.0.0.0:25672 0.0.0.0:* LISTEN 12914/beam
tcp 0 0 192.168.20.143:3306 0.0.0.0:* LISTEN 12517/MysqLd
tcp 0 52 192.168.20.143:22 192.168.20.210:58818 ESTABLISHED 14292/sshd: root@pt
tcp 0 0 127.0.0.1:42502 127.0.0.1:4369 ESTABLISHED 12914/beam
tcp 0 0 127.0.0.1:4369 127.0.0.1:42502 ESTABLISHED 13000/epmd
tcp 0 0 192.168.20.143:22 192.168.20.210:53631 ESTABLISHED 11895/sshd: root@pt
tcp6 0 0 :::22 :::* LISTEN 862/sshd
tcp6 0 0 ::1:25 :::* LISTEN 1304/master
tcp6 0 0 :::5672 :::* LISTEN 12914/beam
udp 0 0 127.0.0.1:323 0.0.0.0:* 634/chronyd
udp6 0 0 ::1:323 :::* 634/chronyd
[root@openstack sysconfig]#
https://serverfault.com/questions/286381/memcached-problems-failed-to-listen-on-tcp-port-11211
大意是memcached绑定到第一个IP地址上面，127.0.0.1与localhost是冲突的，所以偿试绑定到第二块网卡的地址上面，但是我的测试环境里面并没有第二块网卡，所以我就删除了/etc/sysconfig/memcached里面的option行并保存
然后重新启动服务
[root@openstack sysconfig]# systemctl restart memcached
[root@openstack sysconfig]# systemctl status memcached
● memcached.service - memcached daemon
Loaded: loaded (/usr/lib/systemd/system/memcached.service; enabled; vendor preset: disabled)
Active: active (running) since Mon 2017-04-24 13:57:24 CST; 2s ago
Main PID: 14485 (memcached)
CGroup: /system.slice/memcached.service
└─14485 /usr/bin/memcached -p 11211 -u memcached -m 64 -c 1024
Apr 24 13:57:24 openstack systemd[1]: Started memcached daemon.
Apr 24 13:57:24 openstack systemd[1]: Starting memcached daemon...
[root@openstack sysconfig]#
这样就解决了这个问题
