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mysql dba系统学习(19)配置mysql+lvs+keeplived实现Mysql读操作的负载均衡

更新时间:2022-05-04 14:04:39

配置mysql+lvs+keeplived实现Mysql读操作的负载均衡

环境:

test1192.168.46.131master

test2192.168.46.130slave备份test库

test3调度器

1、安装与配置Keepalived

首先在节点test1、test2上安装Keepalived软件,软件安装非常简单。

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[root@test1 ]# yum install -y openssl-devel
[root@test1 ~]# wget  http://www.keepalived.org/software/keepalived-1.2.1.tar.gz
[root@test1 ~]# tar zxvf keepalived-1.2.1.tar.gz
[root@test1 ~]# cd keepalived-1.2.1
[root@test1 keepalived-1.2.1]# ./configure --prefix=/usr/local/keepalived
[root@test1 keepalived-1.2.1]# make && make install
[root@test1 ~]# cp /usr/local/keepalived/etc/sysconfig/keepalived  /etc/sysconfig/
[root@test1 ~]# cp /usr/local/keepalived/etc/rc.d/init.d/keepalived  /etc/init.d/
[root@test1 ~]# mkdir  /etc/keepalived
[root@test1 ~]# cp  /usr/local/keepalived/etc/keepalived  /keepalived.conf  /etc/keepalived/
[root@test1 ~]# ln -s  /usr/local/keepalived/sbin/keepalived  /usr/sbin/
[root@test1 ~]# service keepalived start
Starting keepalived:                                       [  OK  ]

Keepalived的配置也非常简单,仅仅需要一个配置文件即可完成HAclusterlvs服务节点监控功能,在通过Keepalived搭建高可用的LVS集群实例中,主、备DirectorServer都需要安装Keepalived软件,安装成功后,默认的配置文件路径为/etc/Keepalived/Keepalived.conf

一个完整的keepalived配置文件,有三个部分组成,分别是全局定义部分、vrrp实例定义部分以及虚拟服务器定义部分,配置好的文件内容如下:

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! Configuration File for keepalived
global_defs {
notification_email {
root@localhost
}
notification_email_from  root@localhost
smtp_server 192.168.46.131
smtp_connect_timeout 30
router_id LVS_MASTER
}
vrrp_instance VI_1 {
state MASTER      //备库为BACKUP
interface eth2     //通过的网卡
virtual_router_id 51
priority 100      //备库为99
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.46.100
}
}
virtual_server 192.168.46.100 3306 {
delay_loop 30
lb_algo rr
lb_kind DR
persistence_timeout 50
protocol TCP
real_server 192.168.46.131 3306 {
weight 1
MISC_CHECK{
misc_path "/etc/keepalived/check_slave.pl 192.168.46.131"
misc_dynamic
}
}
real_server 192.168.46.130 3306 {
weight 1
MISC_CHECK{
misc_path "/etc/keepalived/check_slave.pl 192.168.46.130"
misc_dynamic
}
}
}
}



2,check_slave.pl检测mysql

check_slave.pl是用perl写的一个检测脚本,定时在slave机器上执行showslavestatus\G命令,检查Slave_IO_RunningSlave_SQL_RunningSeconds_Behind_Master三个值。Slave_IO_RunningSlave_SQL_Running有一个值为No就自动从LVSrealserver列表去掉,不再对外提供服务,如果这两个值为Yes检查Seconds_Behind_Master大于设定的值也会自动从对外服务机器列表里面去掉。三个值同时满足时又会被加入到服务列表,对外提供服务。这个检测脚本内容如下:

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#!/usr/bin/perl -w
use DBI;
use DBD::mysql;
# CONFIG VARIABLES
$SBM = 120;
$db "test";
$host $ARGV[0];
$port = 3306;
$user "root";
$pw "mysql";
# SQL query
$query "show slave status";
$dbh = DBI->connect("DBI:mysql:$db:$host:$port"$user$pw, { RaiseError => 0,PrintError => 0 });
if (!defined($dbh)) {
exit 1;
}
$sqlQuery $dbh->prepare($query);
$sqlQuery->execute;
$Slave_IO_Running =  "";
$Slave_SQL_Running "";
$Seconds_Behind_Master "";
while (my $ref $sqlQuery->fetchrow_hashref()) {
$Slave_IO_Running $ref->{'Slave_IO_Running'};
$Slave_SQL_Running $ref->{'Slave_SQL_Running'};
$Seconds_Behind_Master $ref->{'Seconds_Behind_Master'};
}
$sqlQuery->finish;
$dbh->disconnect();
if $Slave_IO_Running eq "No" || $Slave_SQL_Running eq "No" ) {
exit 1;
else {
if $Seconds_Behind_Master $SBM ) {
exit 1;
else {
exit 0;
}
}


3、安装配置lvs

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[root@test1 ~]# yum install -y ipvsadm
[root@test1 ~]# lsmod  |grep ip_vs
[root@test1 ~]# modprobe  ip_vs
[root@test1 ~]# lsmod  |grep ip_vs
ip_vs                 122241  0
这里不能靠进程来判断是不是加载了ip_vs模块,因为这里就是一个命令,没有产生进程。
vim /etc/init.d/lvsdrrip
#!/bin/bash
#DR server
VIP=192.168.46.100
case "$1" in
start)
echo "start LVS of DR"
/sbin/ifconfig lo:0 $VIP broadcast $VIP netmask 255.255.255.255 up
/sbin/route add -host $VIP dev lo:0
echo "1" > /proc/sys/net/ipv4/conf/lo/arp_ignore
echo "2" > /proc/sys/net/ipv4/conf/lo/arp_announce
echo "1" > /proc/sys/net/ipv4/conf/all/arp_ignore
echo "2" > /proc/sys/net/ipv4/conf/all/arp_announce
;;
stop)
echo "stop LVS of DR"
/sbin/ifconfig lo:0 down
echo "0" > /proc/sys/net/ipv4/conf/lo/arp_ignore
echo "0" > /proc/sys/net/ipv4/conf/lo/arp_announce
echo "0" > /proc/sys/net/ipv4/conf/all/arp_ignore
echo "0" > /proc/sys/net/ipv4/conf/all/arp_announce
;;
*)
echo "Usage:$0 {start|stop}"
esac
exit
1


4,test1和test2上安装mysql服务,test1为master,test2为slave

参考http://wolfword.blog.51cto.com/4892126/1290938


5,test3调度器安装lvsdr

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[root@test3 ~]# vim  /etc/init.d/lvsdr
#!/bin/bash
VIP=192.168.46.100
RIP1=192.168.46.131
RIP2=192.168.46.130
case "$1" in
start)
echo "start LVS of DirectorServer DR"
/sbin/iptables -F
/sbin/ipvsadm -C
/sbin/ifconfig eth0:0 $VIP broadcast $VIP  netmask 255.255.255.0  up
/sbin/ipvsadm  -A -t $VIP:3306  -s rr
/sbin/ipvsadm  -a -t $VIP:3306  -r  $RIP1 -g
/sbin/ipvsadm  -a -t $VIP:3306  -r  $RIP2 -g
/sbin/ipvsadm
;;
stop)
echo "stop  LVS of DirectorServer DR"
echo "0" >/proc/sys/net/ipv4/ip_forward
/sbin/ipvsadm -C
/sbin/ifconfig eth0:0 down
;;
*)
[root@test3  ~]#chown +x /etc/init.d/lvsdr




本文转自陈仲阳0 51CTO博客,原文链接:http://blog.51cto.com/wolfword/1291868