Linux下keepalived+mysql實現高可用

時間 2020-05-09

標籤 linux keepalived+mysql keepalived mysql 實現可用欄目 Linux 简体版

原文原文鏈接

首先在搭建前分析，想用keepalived實現mysql高可用，那麼先的對keepalived+lvs跟mysql主主複製有所瞭解。由於mysql+keepalived架構是在keepalived+lvs跟mysql主主複製的基礎上實現的lvs+keepalived跟mysql主主複製，在前面的博文中已經介紹過了這裏不囉嗦了。mysql

lvs+keepalived連接：http://duyunlong.blog.51cto.com/1054716/1118447,linux

mysql主主複製連接：http://duyunlong.blog.51cto.com/1054716/1306841sql

咱們的目標是，兩臺mysql服務器若是其中有一臺mysql服務器掛掉後，另一臺能立馬接替其進行工做。所以咱們就必須保證兩臺mysql數據庫的數據徹底同樣，並且當掛掉的那一臺從新啓動的話，再也不會被客戶端繼被訪問，而是會充當備機跟如今工做的mysql進行數據同步，一直到提供服務的那臺掛掉後再接替其工做。如此周而復始的實現了mysql的高可用。在一般狀況下實現這種模式的keepalived無疑是最好的選擇。由於有虛擬IP的緣由，若是有一臺mysql掛掉了，keepalived會從服務器羣中剔除，而客戶端訪問會被切換到另一臺接替其工做的機器上。數據庫

在搭建的時候一些注意事項，mysql主主複製跟lvs+keepalived搭建的注意事情前面博文已經提升這裏就再也不囉嗦。在搭建完畢後，由於arp的緣由不可以實現自由切換。這就是要注意的重點。vim

vim /etc/sysctl.conf
#.............前面部分省去
#######如下是文件末尾添加的部分######
net.ipv4.conf.all.arp_ignore = 1
net.ipv4.conf.all.arp_announce = 2
net.ipv4.conf.lo.arp_ignore = 1
net.ipv4.conf.lo.arp_announce = 2
##這4行的主要做用是本地arp不做迴應##

添加完後保存退出，並執行：sysctl -p使其生效
bash

[root@mysql-ha1 ~]# sysctl -p
net.ipv4.ip_forward = 0
net.ipv4.conf.default.rp_filter = 1
net.ipv4.conf.default.accept_source_route = 0
kernel.sysrq = 0
kernel.core_uses_pid = 1
kernel.msgmnb = 65536
kernel.msgmax = 65536
kernel.shmmax = 68719476736
kernel.shmall = 4294967296
net.ipv4.conf.all.send_redirects = 0
net.ipv4.conf.default.send_redirects = 0
net.ipv4.conf.eth0.send_redirects = 0
net.ipv4.conf.eth0.send_redirects = 0
net.ipv4.conf.all.arp_ignore = 1
net.ipv4.conf.all.arp_announce = 2
net.ipv4.conf.lo.arp_ignore = 1
net.ipv4.conf.lo.arp_announce = 2

下面具體操做，首先有兩臺mysql機器已經搭建好了mysql的主主複製服務器

vip:192.168.5.55架構

mysql-ha1:192.168.5.234ssh

mysql-ha2:192.168.5.155tcp

在兩臺mysql機器上都安裝ipvsadm,keepalived，首先在mysql-ha1(192.168.5.234)安裝

[root@mysql-ha1 src]# wget http://www.keepalived.org/software/keepalived-1.2.2.tar.gz
[root@mysql-ha1 src]# wget http://www.linuxvirtualserver.org/software/kernel-2.6/ipvsadm-1.26.tar.gz
[root@mysql-ha1 src]# yum -y install kernel-devel make gcc openssl-devel libnl* popt*
[root@mysql-ha1 src]# ln -s /usr/src/kernels/2.6.32-220.13.1.el6.x86_64/ /usr/src/linux
[root@mysql-ha1 src]# tar -zxvf ipvsadm-1.26.tar.gz
[root@mysql-ha1 src]# cd ipvsadm-1.26/
[root@mysql-ha1 ipvsadm-1.26]# make
[root@mysql-ha1 ipvsadm-1.26]# make install
[root@mysql-ha1 ipvsadm-1.26]# cd ..
[root@mysql-ha1 src]# tar -zxvf keepalived-1.2.2.tar.gz
[root@mysql-ha1 src]# cd keepalived-1.2.2/
[root@mysql-ha1 keepalived-1.2.2]# ./configure --with-kernel-dir=/usr/src/kernels/2.6.32-358.2.1.el6.x86_64/
[root@mysql-ha1 keepalived-1.2.2]# make && make install
[root@mysql-ha1 keepalived-1.2.2]# cp /usr/local/etc/rc.d/init.d/keepalived /etc/rc.d/init.d/
[root@mysql-ha1 keepalived-1.2.2]# cp /usr/local/etc/sysconfig/keepalived /etc/sysconfig/
[root@mysql-ha1 keepalived-1.2.2]# mkdir /etc/keepalived
[root@mysql-ha1 keepalived-1.2.2]# cp /usr/local/etc/keepalived/keepalived.conf /etc/keepalived/
[root@mysql-ha1 keepalived-1.2.2]# cp /usr/local/sbin/keepalived /usr/sbin/

在mysql-ha2（192.168.5.155）也一樣進行安裝

而後咱們編輯keepalived配置文件，下面是mysql-ha1（192.168.5.234）上的配置文件內容

[root@mysql-ha1 ~]# >/etc/keepalived/keepalived.conf
[root@mysql-ha1 ~]# vim /etc/keepalived/keepalived.conf
#! Configuration File for keepalived
global_defs {
router_id mysql-ha1 #修改成本身的主機名
             }
##################第一部分###################
vrrp_instance VI_1 {
     state BACKUP #都修改爲BACKUP
     interface eth0
     virtual_router_id 60 #默認51 主從都修改成60
     priority 100 #在mysql-ha2上LVS上修改爲80
     advert_int 1
     nopreempt #不搶佔資源，意思就是它活了以後也不會再把主搶回來
     authentication {
     auth_type PASS
     auth_pass 1111
     }
virtual_ipaddress {
     192.168.5.55
     }
}
##################第二部分###################
virtual_server 192.168.5.55 3306 {
     delay_loop 6
     lb_algo wrr
     lb_kind DR
     nat_mask 255.255.255.0
     persistence_timeout 50
     protocol TCP
 real_server 192.168.5.234 3306 {
     weight 1
     notify_down /usr/local/mysql/bin/mysql.sh
     TCP_CHECK {
         connect_timeout 10
         nb_get_retry 3
         connect_port 3306
         }
     }
}

這裏須要注意的是，notify_down /usr/local/mysql/bin/mysql.sh這個選項，這個是是在keepalived檢測不到mysql的時候要執行的腳本，從上面的配置文件來看real服務器只有本機。那麼，keeaplived若是啓動，客戶端也只是訪問本機的mysql。nopreempt這個選下也得注意，這個是不搶佔資源在優先級高的機器上配置就能夠。

看下這個腳本的內容：

[root@mysql-ha1 ~]# vim /usr/local/mysql/bin/mysql.sh
#!/bin/bash
pkill keepalived
[root@mysql-ha1 ~]# chmod +x /usr/local/mysql/bin/mysql.sh

腳本內容就一條命令：pkill keepalived，主要做用是若是本機的mysql掛掉了，那麼同時會殺死本機的keepalived，這樣另一臺就會接替他工做，虛擬IP也會被另外一臺接管，若是不殺死keepalived虛擬IP不會被另外一臺接管，mysql訪問也就不會切換過去。

測試下若是，mysql服務器掛掉，腳本是否能夠殺死keepalived

[root@mysql-ha1 ~]# ps aux | grep keepalived
root      2518  0.0  0.0  41796   936 ?        Ss   19:35   0:00 keepalived -D
root      2519  0.0  0.1  43900  2152 ?        S    19:35   0:00 keepalived -D
root      2520  0.0  0.0  43900  1572 ?        S    19:35   0:00 keepalived -D
root      2610  0.0  0.0 103240   860 pts/0    S+   23:07   0:00 grep keepalived
[root@mysql-ha1 ~]# netstat -ntlp
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address               Foreign Address             State       PID/Program name
tcp        0      0 0.0.0.0:3306                0.0.0.0:*                   LISTEN      2237/mysqld
tcp        0      0 0.0.0.0:22                  0.0.0.0:*                   LISTEN      1041/sshd
tcp        0      0 127.0.0.1:25                0.0.0.0:*                   LISTEN      1416/master
tcp        0      0 0.0.0.0:5672                0.0.0.0:*                   LISTEN      1429/qpidd
tcp        0      0 :::22                       :::*                        LISTEN      1041/sshd
tcp        0      0 ::1:25                      :::*                        LISTEN      1416/master
[root@mysql-ha1 ~]# service mysqld stop
Shutting down MySQL... SUCCESS!
[root@mysql-ha1 ~]# ps aux | grep keepalived
root      2640  0.0  0.0 103240   856 pts/0    S+   23:07   0:00 grep keepalived
[root@mysql-ha1 ~]# netstat -ntlp
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address               Foreign Address             State       PID/Program name
tcp        0      0 0.0.0.0:22                  0.0.0.0:*                   LISTEN      1041/sshd
tcp        0      0 127.0.0.1:25                0.0.0.0:*                   LISTEN      1416/master
tcp        0      0 0.0.0.0:5672                0.0.0.0:*                   LISTEN      1429/qpidd
tcp        0      0 :::22                       :::*                        LISTEN      1041/sshd
tcp        0      0 ::1:25                      :::*                        LISTEN      1416/master
[root@mysql-ha1 ~]#

能夠看到當mysqld服務器掛掉後，腳本生效同時殺死本機keepalived使得mysql故障轉移。這時另外一臺keepalived會接替它工做。

一樣看下mysql-ha2(192.168.5.155)上keepalived配置文件

[root@mysql-ha2 ~]# vim /etc/keepalived/keepalived.conf
#! Configuration File for keepalived
global_defs {
router_id mysql-ha1 #修改成本身的主機名
             }
##################第一部分###################
vrrp_instance VI_1 {
     state BACKUP #都修改爲BACKUP
     interface eth1
     virtual_router_id 60 #默認51 主從都修改成60
     priority 80 #在mysql-ha1上LVS上修改爲100
     advert_int 1
     authentication {
     auth_type PASS
     auth_pass 1111
     }
virtual_ipaddress {
     192.168.5.55
     }
}
##################第二部分###################
virtual_server 192.168.5.55 3306 {
     delay_loop 6
     lb_algo wrr
     lb_kind DR
     nat_mask 255.255.255.0
     persistence_timeout 50
     protocol TCP
 real_server 192.168.5.155 3306 {
     weight 1
     notify_down /usr/local/mysql/bin/mysql.sh
     TCP_CHECK {
         connect_timeout 10
         nb_get_retry 3
         connect_port 3306
         }
     }
}

配置完畢後能夠查看下keealived有沒有檢測到本機的mysql。（啓動的時候先啓動mysql在啓動keepalived,要不mysql沒起來啓動keepalived會被腳本殺死。）

先看下mysql-ha1(192.168.5.234)

[root@mysql-ha1 ~]# service mysqld start
Starting MySQL.. SUCCESS!
[root@mysql-ha1 ~]# /etc/init.d/keepalived start
正在啓動 keepalived：
[root@mysql-ha1 ~]# ipvsadm -Ln
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
  -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
TCP  192.168.5.55:mysql wrr persistent 50
  -> 192.168.5.234:mysql          Local   1      0          0

而後再看下mysql-ha1(192.168.5.155)

[root@mysql-ha2 ~]# service mysqld start
Starting MySQL.. SUCCESS!
[root@mysql-ha2 ~]# /etc/init.d/keepalived start
正在啓動 keepalived：                                      [肯定]
[root@mysql-ha2 ~]# ipvsadm -Ln      
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
  -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
TCP  192.168.5.55:3306 wrr persistent 50
  -> 192.168.5.155:3306           Local   1      0          0

測試只開啓mysql-ha1(192.168.5.234)mysql服務跟keepalived用客戶端連接虛擬ip

[root@mysql-ha1 ~]# ps aux | grep keepalived
root      2977  0.0  0.0  41796   936 ?        Ss   23:14   0:00 keepalived -D
root      2978  0.0  0.1  43900  2156 ?        S    23:14   0:00 keepalived -D
root      2979  0.0  0.0  43900  1576 ?        S    23:14   0:00 keepalived -D
root      2982  0.0  0.0 103240   860 pts/0    S+   23:16   0:00 grep keepalived
[root@mysql-ha1 ~]# netstat -ntlp
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address               Foreign Address             State       PID/Program name
tcp        0      0 0.0.0.0:3306                0.0.0.0:*                   LISTEN      2917/mysqld
tcp        0      0 0.0.0.0:22                  0.0.0.0:*                   LISTEN      1041/sshd
tcp        0      0 127.0.0.1:25                0.0.0.0:*                   LISTEN      1416/master
tcp        0      0 0.0.0.0:5672                0.0.0.0:*                   LISTEN      1429/qpidd
tcp        0      0 :::22                       :::*                        LISTEN      1041/sshd
tcp        0      0 ::1:25                      :::*                        LISTEN      1416/master

mysql-ha2(192.168.5.155)

[root@mysql-ha2 ~]# ps aux | grep keepalived
root     10576  0.0  0.0   5980   756 pts/4    S+   15:24   0:00 grep keepalived
[root@mysql-ha2 ~]# netstat -ntlp
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address               Foreign Address             State       PID/Program name
tcp        0      0 0.0.0.0:22                  0.0.0.0:*                   LISTEN      4776/sshd
tcp        0      0 127.0.0.1:25                0.0.0.0:*                   LISTEN      1101/master
tcp        0      0 0.0.0.0:5672                0.0.0.0:*                   LISTEN      1114/qpidd
tcp        0      0 :::22                       :::*                        LISTEN      4776/sshd
tcp        0      0 ::1:25                      :::*                        LISTEN      1101/master

而後用客戶端：192.168.5.10鏈接

C:\Users\Administrator>mysql -uduyunlong -p123456 -h192.168.5.55
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 33
Server version: 5.5.22-log Source distribution
Type 'help;' or '\h' for help. Type '\c' to clear the buffer.
mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| test               |
+--------------------+
4 rows in set (0.02 sec)
mysql>

而後把mysql-ha1（192.168.5.234）mysql服務關掉，開啓mysql-ha2(192.168.5.155)上的mysql服務跟keepalived。而後不退出mysql，繼續查看數據庫：

mysql-ha1(192.168.5.234)

[root@mysql-ha1 ~]# service mysqld stop
Shutting down MySQL... SUCCESS!

mysql-ha2(192.168.5.155)

[root@mysql-ha2 ~]# service mysqld start
Starting MySQL.. SUCCESS!
[root@mysql-ha2 ~]# /etc/init.d/keepalived start
正在啓動 keepalived：                                      [肯定]
[root@mysql-ha2 ~]#

客戶端：192.168.5.10

mysql> show databases;
ERROR 2006 (HY000): MySQL server has gone away
No connection. Trying to reconnect...
Connection id:    4
Current database: *** NONE ***
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| test               |
+--------------------+
4 rows in set (0.01 sec)
mysql>

切換很快，大概在2到3秒之間！