这里有新鲜出炉的Mysql教程,程序狗速度看过来!
MySQL是一个开放源码的小型关联式数据库管理系统,开发者为瑞典MySQL AB公司。MySQL被广泛地应用在Internet上的中小型网站中。由于其体积小、速度快、总体拥有成本低,尤其是开放源码这一特点,许多中小型网站为了降低网站总体拥有成本而选择了MySQL作为网站数据库。
这篇文章主要介绍了keepalived+haproxy实现MySQL高可用负载均衡的配置方法,通过这两个软件可以有效地使MySQL脱离故障及进行健康检测,需要的朋友可以参考下
Keepalived
由于在生产环境使用了mysqlcluster,需要实现高可用负载均衡,这里提供了keepalived+haproxy来实现.
keepalived主要功能是实现真实机器的故障隔离及负载均衡器间的失败切换.可在第3,4,5层交换.它通过VRRPv2(Virtual Router Redundancy Protocol) stack实现的.
Layer3:Keepalived会定期向服务器群中的服务器.发送一个ICMP的数据包(既我们平时用的Ping程序),如果发现某台服务的IP地址没有激活,Keepalived便报告这台服务器失效,并将它从服务器群中剔除,这种情况的典型例子是某台服务器被非法关机。Layer3的方式是以服务器的IP地址是否有效作为服务器工作正常与否的标准。
Layer4:主要以TCP端口的状态来决定服务器工作正常与否。如web server的服务端口一般是80,如果Keepalived检测到80端口没有启动,则Keepalived将把这台服务器从服务器群中剔除。
Layer5:在网络上占用的带宽也要大一些。Keepalived将根据用户的设定检查服务器程序的运行是否正常,如果与用户的设定不相符,则Keepalived将把服务器从服务器群中剔除。
Software Design
keepalived启动后会有单个进程
- 8352 ? Ss 0:00 /usr/sbin/keepalived
- 8353 ? S 0:00 \_ /usr/sbin/keepalived
- 8356 ? S 0:01 \_ /usr/sbin/keepalived
父进程:内存管理,子进程管理等等
子进程:VRRP子进程
子进程:Healthchecking 子进程
实例
2台mysqlcluster 10.1.6.203 master 10.1.6.205 backup
vip 10.1.6.173
目的访问10.1.6.173 3366端口 分别轮询通过haproxy转发到10.1.6.203 3306 和10.1.6.205 3306
mysqlcluster搭建参照之前博客,这里在2台机上安装keepalived
- root@10.1.6.203:~# apt-get install keepalived
- root@10.1.6.203:~# cat /etc/keepalived/keepalived.conf
- vrrp_script chk_haproxy {
- script "killall -0 haproxy" # verify the pid existance
- interval 2 # check every 2 seconds
- weight -2 # add 2 points of prio if OK
- }
- vrrp_instance VI_1 {
- interface eth1 # interface to monitor
- state MASTER
- virtual_router_id 51 # Assign one ID for this route
- priority 101 # 101 on master, 100 on backup
- nopreempt
- debug
- virtual_ipaddress {
- 10.1.6.173
- }
- track_script { #注意大括号空格
- chk_haproxy
- }
- notify_master /etc/keepalived/scripts/start_haproxy.sh #表示当切换到master状态时,要执行的脚本
- notify_fault /etc/keepalived/scripts/stop_keepalived.sh #故障时执行的脚本
- notify_stop /etc/keepalived/scripts/stop_haproxy.sh #keepalived停止运行前运行notify_stop指定的脚本 }
VRRPD配置包括三个类:
这里使用了 VRRP实例, VRRP脚本
注意配置选项:
stat:指定instance(Initial)的初始状态,就是说在配置好后,这台服务器的初始状态就是这里指定的,但这里指定的不算,还是得要通过竞选通过优先级来确定,里如果这里设置为master,但如若他的优先级不及另外一台,那么这台在发送通告时,会发送自己的优先级,另外一台发现优先级不如自己的高,那么他会就回抢占为master
- vrrp_script chk_haproxy {
- script "killall -0 haproxy" # verify the pid existance
- interval 2 # check every 2 seconds 脚本执行间隔
- weight -2 # add 2 points of prio if OK 脚本结果导致的优先级变更:2表示优先级+2;-2则表示优先级-2
- }
然后在实例(vrrp_instance)里面引用,有点类似脚本里面的函数引用一样:先定义,后引用函数名
- track_script {
- chk_haproxy
- }
注意:VRRP脚本(vrrp_script)和VRRP实例(vrrp_instance)属于同一个级别
- root@10.1.6.203:scripts# cat start_haproxy.sh
- #!/bin/bash
- sleep 5
- get=`ip addr |grep 10.1.6.173 |wc -l`
- echo $get >> /etc/keepalived/scripts/start_ha.log
- if [ $get -eq 1 ]
- then
- echo "`date +%c` success to get vip" >> /etc/keepalived/scripts/start_ha.log
- /usr/local/sbin/haproxy -f /etc/haproxy/haproxy.cfg
- else
- echo "`date +%c` can not get vip" >> /etc/keepalived/scripts/start_ha.log
- fi
- root@10.1.6.203:scripts# cat stop_keepalived.sh
- #!/bin/bash
- pid=`pidof keepalived`
- if [ $pid == "" ]
- then
- echo "`date +%c` no keepalived process id" >> /etc/keepalived/scripts/stop_keep.log
- else
- echo "`date +%c` will stop keepalived " >> /etc/keepalived/scripts/stop_keep.log
- /etc/init.d/keepalived stop
- fi
- /etc/init.d/keepalived stop
- root@10.1.6.203:scripts# cat stop_haproxy.sh
- #!/bin/bash
- pid=`pidof haproxy`
- echo "`date +%c` stop haproxy" >> /etc/keepalived/scripts/stop_ha.log
- kill -9 $pid
同理配置10.1.6.205
- root@10.1.6.205:~# cat /etc/keepalived/keepalived.conf
- vrrp_script chk_haproxy {
- script "killall -0 haproxy" # verify the pid existance
- interval 2 # check every 2 seconds
- weight 2 # add 2 points of prio if OK
- }
- vrrp_instance VI_1 {
- interface eth1 # interface to monitor
- state BACKUP
- virtual_router_id 51 # Assign one ID for this route
- priority 100 # 101 on master, 100 on backup
- virtual_ipaddress {
- 10.1.6.173
- }
- track_script {
- chk_haproxy
- }
- notify_master /etc/keepalived/scripts/start_haproxy.sh
- notify_fault /etc/keepalived/scripts/stop_keepalived.sh
- notify_stop /etc/keepalived/scripts/stop_haproxy.sh
- }
HAProxy
下面再介绍下haproxy
HAProxy是一款基于TCP(第四层)和HTTP(第七层)应用的代理软件,它也可作为负载均衡器.可以支持数以万计的并发连接.同时可以保护服务器不暴露到网络上,通过端口映射.它还自带监控服务器状态的页面.
安装haproxy
- wget -O/tmp/haproxy-1.4.22.tar.gz http://haproxy.1wt.eu/download/1.4/src/haproxy-1.4.22.tar.gz
- tar xvfz /tmp/haproxy-1.4.22.tar.gz -C /tmp/
- cd /tmp/haproxy-1.4.22
- make TARGET=linux26
- make install
haproxy需要对每一个mysqlcluster服务器进行健康检查
1.在2台主机分别配置haproxy.cfg
- root@10.1.6.203:scripts# cat /etc/haproxy/haproxy.cfg
- global
- maxconn 51200 #默认最大连接数
- #uid 99
- #gid 99
- daemon #以后台形式运行haproxy
- #quiet
- nbproc 1 #进程数量(可以设置多个进程提高性能)
- pidfile /etc/haproxy/haproxy.pid #haproxy的pid存放路径,启动进程的用户必须有权限访问此文件
- defaults
- mode tcp #所处理的类别 (#7层 http;4层tcp )
- option redispatch #serverId对应的服务器挂掉后,强制定向到其他健康的服务器
- option abortonclose #当服务器负载很高的时候,自动结束掉当前队列处理比较久的连接
- timeout connect 5000s #连接超时
- timeout client 50000s #客户端超时
- timeout server 50000s #服务器超时
- log 127.0.0.1 local0 #错误日志记录
- balance roundrobin #默认的负载均衡的方式,轮询方式
- listen proxy
- bind 10.1.6.173:3366 #监听端口
- mode tcp #http的7层模式
- option httpchk #心跳检测的文件
- server db1 10.1.6.203:3306 weight 1 check port 9222 inter 12000 rise 3 fall 3 #服务器定义,check inter 12000是检测心跳频率 rise 3是3次正确认为服务器可用, fall 3是3次失败认为服务器不可用,weight代表权重
- server db2 10.1.6.205:3306 weight 1 check port 9222 inter 12000 rise 3 fall 3
- listen haproxy_stats
- mode http
- bind 10.1.6.173:8888
- option httplog
- stats refresh 5s
- stats uri /status #网站健康检测URL,用来检测HAProxy管理的网站是否可以用,正常返回200,不正常返回503
- stats realm Haproxy Manager
- stats auth admin:p@a1SZs24 #账号密码
- root@10.1.6.205:~$ cat /etc/haproxy/haproxy.cfg
- global
- maxconn 51200
- #uid 99
- #gid 99
- daemon
- #quiet
- nbproc 1
- pidfile /etc/haproxy/haproxy.pid
- defaults
- mode tcp
- option redispatch
- option abortonclose
- timeout connect 5000s
- timeout client 50000s
- timeout server 50000s
- log 127.0.0.1 local0
- balance roundrobin
- listen proxy
- bind 10.1.6.173:3366
- mode tcp
- option httpchk
- server db1 10.1.6.203:3306 weight 1 check port 9222 inter 12000 rise 3 fall 3
- server db2 10.1.6.205:3306 weight 1 check port 9222 inter 12000 rise 3 fall 3
- listen haproxy_stats
- mode http
- bind 10.1.6.173:8888
- option httplog
- stats refresh 5s
- stats uri /status
- stats realm Haproxy Manager
- stats auth admin:p@a1SZs24
2.安装xinetd
- root@10.1.6.203 : ~#apt - get install xinetd
3.在每个节点添加xinetd服务脚本和mysqlchk端口号
- root@10.1.6.203:~# vim /etc/xinetd.d/mysqlchk
- # default: on
- # description: mysqlchk
- service mysqlchk #需要在servive定义
- {
- flags = REUSE
- socket_type = stream
- port = 9222
- wait = no
- user = nobody
- server = /opt/mysqlchk
- log_on_failure += USERID
- disable = no
- per_source = UNLIMITED
- bind = 10.1.6.173
- }
- root@10.1.6.203:~# vim /etc/services
- mysqlchk 9222/tcp # mysqlchk
4.编写mysqlchk监控服务脚本
- root@10.1.6.203:~# ls -l /opt/mysqlchk
- -rwxr--r-- 1 nobody root 1994 2013-09-17 11:27 /opt/mysqlchk
- root@10.1.6.203:~# cat /opt/mysqlchk
- #!/bin/bash
- #
- # This script checks if a mysql server is healthy running on localhost. It will
- # return:
- # "HTTP/1.x 200 OK\r" (if mysql is running smoothly)
- # - OR -
- # "HTTP/1.x 500 Internal Server Error\r" (else)
- #
- # The purpose of this script is make haproxy capable of monitoring mysql properly
- #
- MYSQL_HOST="localhost"
- MYSQL_SOCKET="/var/run/mysqld/mysqld.sock"
- MYSQL_USERNAME="mysqlchkusr" #该账户密码需要在mysql里添加
- MYSQL_PASSWORD="secret"
- MYSQL_OPTS="-N -q -A"
- TMP_FILE="/dev/shm/mysqlchk.$$.out"
- ERR_FILE="/dev/shm/mysqlchk.$$.err"
- FORCE_FAIL="/dev/shm/proxyoff"
- MYSQL_BIN="/opt/mysqlcluster/mysql-cluster-gpl-7.2.6-linux2.6-x86_64/bin/mysql"
- CHECK_QUERY="select 1"
- preflight_check()
- {
- for I in "$TMP_FILE" "$ERR_FILE"; do
- if [ -f "$I" ]; then
- if [ ! -w $I ]; then
- echo -e "HTTP/1.1 503 Service Unavailable\r\n"
- echo -e "Content-Type: Content-Type: text/plain\r\n"
- echo -e "\r\n"
- echo -e "Cannot write to $I\r\n"
- echo -e "\r\n"
- exit 1
- fi
- fi
- done
- }
- return_ok()
- {
- echo -e "HTTP/1.1 200 OK\r\n"
- echo -e "Content-Type: text/html\r\n"
- echo -e "Content-Length: 43\r\n"
- echo -e "\r\n"
- echo -e "<html><body>MySQL is running.</body></html>\r\n"
- echo -e "\r\n"
- rm $ERR_FILE $TMP_FILE
- exit 0
- }
- return_fail()
- {
- echo -e "HTTP/1.1 503 Service Unavailable\r\n"
- echo -e "Content-Type: text/html\r\n"
- echo -e "Content-Length: 42\r\n"
- echo -e "\r\n"
- echo -e "<html><body>MySQL is *down*.</body></html>\r\n"
- sed -e 's/\n$/\r\n/' $ERR_FILE
- echo -e "\r\n"
- rm $ERR_FILE $TMP_FILE
- exit 1
- }
- preflight_check
- if [ -f "$FORCE_FAIL" ]; then
- echo "$FORCE_FAIL found" > $ERR_FILE
- return_fail;
- fi
- $MYSQL_BIN $MYSQL_OPTS --host=$MYSQL_HOST --socket=$MYSQL_SOCKET --user=$MYSQL_USERNAME --password=$MYSQL_PASSWORD -e "$CHECK_QUERY" > $TMP_FILE 2> $ERR_FILE
- if [ $? -ne 0 ]; then
- return_fail;
- fi
- return_ok;
测试
2个节点开启keepalived(主节点会获得vip,自动拉起haproxy),xinetd
- root@10.1.6.203:~# ip add
- 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN
- link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
- inet 127.0.0.1/8 scope host lo
- 2: eth0: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast state DOWN qlen 1000
- link/ether 00:26:b9:36:0f:81 brd ff:ff:ff:ff:ff:ff
- inet 211.151.105.186/26 brd 211.151.105.191 scope global eth0
- 3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
- link/ether 00:26:b9:36:0f:83 brd ff:ff:ff:ff:ff:ff
- inet 10.1.6.203/24 brd 10.1.6.255 scope global eth1
- inet 10.1.6.173/32 scope global eth1
- 4: eth2: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN qlen 1000
- link/ether 00:26:b9:36:0f:85 brd ff:ff:ff:ff:ff:ff
- 5: eth3: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN qlen 1000
- link/ether 00:26:b9:36:0f:87 brd ff:ff:ff:ff:ff:ff
- root@10.1.6.203:~# netstat -tunlp | grep ha
- tcp 0 0 10.1.6.173:3366 0.0.0.0:* LISTEN 1042/haproxy
- tcp 0 0 10.1.6.203:8888 0.0.0.0:* LISTEN 1042/haproxy
- udp 0 0 0.0.0.0:56562 0.0.0.0:* 1042/haproxy
- root@10.1.6.203:~# netstat -tunlp | grep xine
- tcp 0 0 10.1.6.203:9222 0.0.0.0:* LISTEN 30897/xinetd
- root@10.1.6.203:~# ps -ef | grep haproxy
- root 1042 1 0 Sep17 ? 00:00:00 /usr/local/sbin/haproxy -f /etc/haproxy/haproxy.cfg
测试:
通过vip10.1.6.173 3366访问cluster数据库(注意账户dave权限需要加3个ip10.1.6.203,10.1.6.205,10.1.6.173)
- root@10.1.6.203:mgm# mysql -udave -p -h 10.1.6.173 -P 3366
- Enter password:
- Welcome to the MySQL monitor. Commands end with ; or \g.
- Your MySQL connection id is 1344316
- Server version: 5.5.22-ndb-7.2.6-gpl-log MySQL Cluster Community Server (GPL)
- Type 'help;' or '\h' for help. Type '\c' to clear the buffer.
- mysql> show databases;
- +--------------------+
- | Database |
- +--------------------+
- | information_schema |
- | dave |
- | test |
- +--------------------+
- 3 rows in set (0.01 sec)
- mysql>
手动分别使keepalive,haproxy,数据库挂掉.vip10.1.6.173会自动漂到10.1.6.205从上,并不影响vip的访问
通过vip,haproxy查看各节点状态
http://10.1.6.173:8888/status
来源: http://www.phperz.com/article/17/1103/350558.html