memcached high availability cluster building
We need three servers:
- Main server 192.168.247.206
- From server 192.168.247.160
- Client 192.168.247.161
master server
Configure memcached primary and secondary cache nodes[root@lamp ~]# hostnamectl set-hostname master [root@lamp ~]# su [root@master ~]# [root@master ~]# mkdir /abc mkdir: cannot create directory '/abc': File exists [root@master ~]# mount.cifs //192.168.254.10/linuxs /abc Password for root@//192.168.254.10/linuxs: [root@master ~]# cd /abc [root@master abc]# tar zxvf libevent-2.1.8-stable.tar.gz -C /opt [root@master abc]# tar zxvf memcached-1.5.6.tar.gz -C /opt [root@master abc]# mkdir /opt/magent [root@master abc]# tar zxvf magent-0.5.tar.gz -C /opt/magent/ [root@master abc]# yum install gcc gcc-c++ make -y
from server
magent does not need to be installed from the server[root@nginx ~]# hostnamectl set-hostname slave [root@nginx ~]# su [root@slave ~]# [root@slave ~]# mkdir /abc mkdir: cannot create directory '/abc': File exists [root@slave ~]# mount.cifs //192.168.254.10/linuxs /abc Password for root@//192.168.254.10/linuxs: [root@slave ~]# cd /abc [root@slave abc]# tar zxvf libevent-2.1.8-stable.tar.gz -C /opt [root@slave abc]# tar zxvf memcached-1.5.6.tar.gz -C /opt [root@slave abc]# yum install gcc gcc-c++ make -y
Back to main server
[root@master abc]# cd /opt [root@master opt]# ls libevent-2.1.8-stable magent memcached-1.5.6 mysql-5.7.17 rh [root@master opt]# cd libevent-2.1.8-stable/ [root@master libevent-2.1.8-stable]# ./configure --prefix=/usr [root@master libevent-2.1.8-stable]# make && make install [root@master libevent-2.1.8-stable]# cd /opt/memcached-1.5.6/ [root@master memcached-1.5.6]# ./configure --with-libevent=usr [root@master memcached-1.5.6]# make && make install
Switch to from server
[root@slave abc]# cd /opt [root@slave opt]# ls data libevent-2.1.8-stable memcached-1.5.6 nginx-1.12.2 rh [root@slave opt]# cd libevent-2.1.8-stable/ [root@slave libevent-2.1.8-stable]# ./configure --prefix=/usr [root@slave libevent-2.1.8-stable]# make && make install [root@slave libevent-2.1.8-stable]# cd /opt/memcached-1.5.6/ [root@slave memcached-1.5.6]# ./configure -with-libevent=/usr [root@slave memcached-1.5.6]# make && make install
Configure magent on the primary server
[root@master memcached-1.5.6]# cd /opt/magent/ [root@master magent]# ls ketama.c ketama.h magent.c Makefile [root@master magent]# vim ketama.h //Modify the first three lines #ifndef SSIZE_MAX #define SSIZE_MAX 32767 #endif //The last line has an endif, delete it [root@master magent]# vim Makefile //First line modification LIBS = -levent -lm [root@master magent]# make [root@master magent]# ls ketama.c ketama.h ketama.o magent magent.c magent.o Makefile //Add the magent executable, install ssh, and copy the file to the slave server
[root@master magent]# yum install openssh-clients -y [root@master magent]# cp magent /usr/bin/ [root@master magent]# scp magent root@192.168.247.160:/usr/bin [root@master magent]# systemctl stop firewalld [root@master magent]# setenforce 0 #Turn off firewall and enhanced security
The master and slave servers start to install keepalived
[root@master magent]# yum install keepalived -y
[root@slave memcached-1.5.6]# yum install keepalived -y
Modify master profile[root@master magent]# vim /etc/keepalived/keepalived.conf //Delete the original, re-enter, delete the previous copy ! Configuration File for keepalived vrrp_script magent { script "/opt/shell/magent.sh" interval 2 } global_defs { notification_email { acassen@firewall.loc failover@firewall.loc sysadmin@firewall.loc } notification_email_from Alexandre.Cassen@firewall.loc smtp_server 192.168.200.1 smtp_connect_timeout 30 router_id MAGENT_HA } vrrp_instance VI_1 { state MASTER interface ens33 virtual_router_id 51 priority 100 advert_int 1 authentication { auth_type PASS auth_pass 1111 } track_script { magent } virtual_ipaddress { 192.168.247.188 } }[root@slave memcached-1.5.6]# cd /etc/keepalived/ [root@slave keepalived]# ls keepalived.conf [root@slave keepalived]# mv keepalived.conf keepalived.conf.bk [root@slave keepalived]# yum install openssh-clients -y [root@slave keepalived]# scp root@192.168.247.206:/etc/keepalived/keepalived.conf /etc/keepalived/ [root@slave keepalived]# vim keepalived.conf //modify 17 router_id MAGENT_HB 21 state BACKUP 23 virtual_router_id 52 24 priority 95
[root@master magent]# mkdir /opt/shell [root@master magent]# cd /opt/shell/ [root@master shell]# ls [root@master shell]# vim magent.sh #!/bin/bash K=`ps -ef | grep keepalived | grep -v grep | wc -l` if [ $K -gt 0 ]; then magent -u root -n 51200 -l 192.168.247.188 -p 12000 -s 192.168.247.206:11211 -b 192.168.247.160:11211 else pkill -9 magent fi[root@master shell]# chmod +x magent.sh [root@master shell]# ls magent.sh [root@master shell]# ln -s /lib/libevent-2.1.so.6* /usr/lib64/ [root@master shell]# systemctl start keepalived.service [root@master lib64]# netstat -natp | grep 12000 tcp 0 0 192.168.247.188:12000 0.0.0.0:* LISTEN 16635/magent
127 status code error appears, magent shows no file or directory, create soft connection
that will do[root@master shell]# magent -u root -n 51200 -l 192.168.247.188 -p 12000 -s 192.168.247.206:11211 -b 192.168.247.160:11211 magent: error while loading shared libraries: libevent-2.1.so.6: cannot open shared object file: No such file or directory ln -s /lib/libevent-2.1.so.6* /usr/lib64/
Verify it.
[root@master lib64]# cat /var/log/messages | grep "Transition to MASTER STATE" Feb 1 23:10:46 lamp Keepalived_vrrp[101923]: VRRP_Instance(VI_1): Transition to MASTER STATE
Verify that the drift address is valid
[root@master lib64]# ip addr 2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether 00:0c:29:d6:c0:8a brd ff:ff:ff:ff:ff:ff inet 192.168.247.206/24 brd 192.168.247.255 scope global dynamic ens33 valid_lft 5438031sec preferred_lft 5438031sec inet 192.168.247.188/32 scope global ens33
[root@slave bin]# mkdir /opt/shell [root@slave bin]# cd /opt/shell/ [root@slave shell]# vim magent.sh #!/bin/bash K=`ps -ef | grep keepalived | grep -v grep | wc -l` if [ $K -gt 0 ]; then magent -u root -n 51200 -l 192.168.247.188 -p 12000 -s 192.168.247.206:11211 -b 192.168.247.160:11211 else pkill -9 magent fi[root@slave shell]# chmod +x magent.sh [root@slave shell]# ln -s /lib/libevent-2.1.so.6* /usr/lib64/ [root@slave shell]# systemctl start keepalived.service [root@slave shell]# netstat -natp | grep 12000 tcp 0 0 192.168.247.188:12000 0.0.0.0:* LISTEN 16132/magent [root@slave shell]# ip addr 2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc inet 192.168.247.188/32 scope global ens33
Start memcached service
[root@master lib64]# memcached -m 512k -u root -d -l 192.168.247.206 -p 11211 [root@master lib64]# netstat -natp | grep 11211 tcp 0 0 192.168.247.206:11211 0.0.0.0:* LISTEN 36267/memcached
[root@slave shell]# memcached -m 512k -u root -d -l 192.168.247.160 -p 11211 [root@slave shell]# netstat -natp | grep 11211 tcp 0 0 192.168.247.160:11211 0.0.0.0:* LISTEN 20928/memcached
Local connection
[root@master lib64]# yum install telnet -y [root@master lib64]# telnet 192.168.247.206 11211 Trying 192.168.247.206... Connected to 192.168.247.206. Escape character is '^]'.
[root@slave shell]# yum install telnet -y [root@slave shell]# telnet 192.168.247.160 11211 Trying 192.168.247.160... Connected to 192.168.247.160. Escape character is '^]'.
Verify client
[root@client ~]# yum install telnet -y [root@client ~]# telnet 192.168.247.188 12000 Trying 192.168.247.188... Connected to 192.168.247.188. Escape character is '^]'. add username 0 0 7 1234567 STORED
At this time, the client exits memcached first, and the primary server is disconnected
quit Connection closed by foreign host. [root@master lib64]# systemctl stop keepalived.service [root@master lib64]#
Still available on the client
[root@client ~]# telnet 192.168.247.188 12000 Trying 192.168.247.188... Connected to 192.168.247.188. Escape character is '^]'. get username VALUE username 0 7 1234567 END