基于mysql的负载均衡有很多种方式,如haproxy,前面一篇博客有介绍,还可以用更高效lvs做负载均衡,下面是基于percona xtradb cluster的三个节点的多主复制+atlas的lvs负载均衡,其实这里是不需要用atlas的,因为atlas是用来做连接池和读写分离的,而多主架构是不需要读写分离的(如果是基于mysql replication的就需要atlas做负载均衡了),但为了测试atlas能不能用lvs做负载均衡,就顺便做了下实验。
1.节点规划
1.1 mysql数据节点:
db169
db172
db173
三个节点为xtradb cluster节点。
1.2 keepalived节点:
db162
db163
虚拟ip为192.168.1.201
haproxy节点(仅为了对比lvs的性能才安装的):db169(部署在xtradb cluster的一个节点上)
1.3 atlas节点:和xtradb cluster节点部署在一起,也为三个节点
注意:atlas和mysql要部署在一个节点上,如果不在一个节点上则不能用lvs dr模式负载均衡
1.4 客户端测试节点:db55
ip地址为192.168.1.* ,节点名为db+ip地址末位
2.安装lvs及keepavlied(db162、db163上)
2.1安装依赖包
yum -y install kernel-devel make gcc openssl-devel libnl*
下载并连接linux kernel文件,注意版本要一致(uname -a)
[root@db163 ~]# ln -s /usr/src/kernels/2.6.32-358.el6.x86_64/ /usr/src/linux
安装keepalived、lvs
[root@db162 ~]# yum install ipvsadm
[root@db162 ~]# yum install keepalived
[root@db163 ~]# yum install ipvsadm
[root@db163 ~]# yum install keepalived
2.2.配置keepavlied,注意lvs不需要单独配置,在keepalived里配置就行了
[root@db162 ~]# cat /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
router_id MySQL_LB1
}
vrrp_sync_group VSG {
group {
MySQL_Loadblancing
}
}
vrrp_instance MySQL_Loadblancing {
state MASTER
interface eth0
virtual_router_id 51
priority 101
advert_int 1
authentication {
auth_type PASS
auth_pass 123456
}
virtual_ipaddress {
192.168.1.201
}
}
virtual_server 192.168.1.201 1234 {
delay_loop 6
lb_algo rr
lb_kind DR
# nat_mask 255.255.255.0
#persistence_timeout 50
protocol TCP
real_server 192.168.1.169 1234 {
weight 3
TCP_CHECK {
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
connect_port 1234
}
}
real_server 192.168.1.172 1234 {
weight 3
TCP_CHECK {
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
connect_port 1234
}
}
real_server 192.168.1.173 1234 {
weight 3
TCP_CHECK {
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
connect_port 1234
}
}
}
备机上的keepalived配置
[root@db163 ~]# cat /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
router_id MySQL_LB2
}
vrrp_sync_group VSG {
group {
MySQL_Loadblancing
}
}
vrrp_instance MySQL_Loadblancing {
state BACKUP
interface eth0
virtual_router_id 51
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass 123456
}
virtual_ipaddress {
192.168.1.201
}
}
virtual_server 192.168.1.201 1234 {
delay_loop 6
lb_algo rr
lb_kind DR
# nat_mask 255.255.255.0
#persistence_timeout 50
protocol TCP
real_server 192.168.1.169 1234 {
weight 3
TCP_CHECK {
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
connect_port 1234
}
}
real_server 192.168.1.172 1234 {
weight 3
TCP_CHECK {
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
connect_port 1234
}
}
real_server 192.168.1.173 1234 {
weight 3
TCP_CHECK {
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
connect_port 1234
}
}
}
3.realserver(数据节点)上的配置
分别在三个数据节点db169、db172、db173上安装如下脚本:
[root@db172 ~]# cat /etc/init.d/lvsdr.sh
#!/bin/bash
VIP=192.168.1.201
. /etc/rc.d/init.d/functions
case "$1" in
start)
/sbin/ifconfig lo down
/sbin/ifconfig lo up
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
/sbin/sysctl -p >/dev/null 2>&1
/sbin/ifconfig lo:0 $VIP netmask 255.255.255.255 up
/sbin/route add -host $VIP dev lo:0
echo "LVS-DR real server starts successfully.\n"
;;
stop)
/sbin/ifconfig lo:0 down
/sbin/route del $VIP >/dev/null 2>&1
echo "0" >/proc/sys/net/ipv4/conf/lo/arp_ignore
echo "0" >/proc/sys/net/ipv4/conf/lo/arp_announce
echo "0" >/proc/sys/net/ipv4/conf/all/arp_ignore
echo "0" >/proc/sys/net/ipv4/conf/all/arp_announce
echo "LVS-DR real server stopped."
;;
status)
isLoOn=`/sbin/ifconfig lo:0 | grep "$VIP"`
isRoOn=`/bin/netstat -rn | grep "$VIP"`
if [ "$isLoOn" == "" -a "$isRoOn" == "" ]; then
echo "LVS-DR real server has to run yet."
else
echo "LVS-DR real server is running."
fi
exit 3
;;
*)
echo "Usage: $0 {start|stop|status}"
exit 1
esac
exit 0
增加x权限:chmod +x /etc/init.d/lvsdr.sh
增加开机自启动:echo "/etc/init.d/lvsdr.sh start" >> /etc/rc.local
4.分别在三个数据节点db169、db172、db173上安装atlas
下载atlas,并yum安装
yum install -y Atlas-2.1.el6.x86_64.rpm
配置atlas
[root@db172 ~]# cat /usr/local/mysql-proxy/conf/test.cnf
[mysql-proxy]
#带#号的为非必需的配置项目
#管理接口的用户名
admin-username = admin
#管理接口的密码
admin-password = 123456
#Atlas后端连接的MySQL主库的IP和端口,可设置多项,用逗号分隔
proxy-backend-addresses = 192.168.1.173:3306
#Atlas后端连接的MySQL从库的IP和端口,@后面的数字代表权重,用来作负载均衡,若省略则默认为1,可设置多项,用逗号分隔
proxy-read-only-backend-addresses = 192.168.1.169:3306@1,192.168.1.172:3306@1
#用户名与其对应的加密过的MySQL密码,密码使用PREFIX/bin目录下的加密程序encrypt加密,下行的user1和user2为示例,将其替换为你的MySQL的用户名和加密密码!
pwds = usr_test:/iZxz+0GRoA=, usr_test2:/iZxz+0GRoA= ,root:/iZxz+0GRoA=
#设置Atlas的运行方式,设为true时为守护进程方式,设为false时为前台方式,一般开发调试时设为false,线上运行时设为true
daemon = true
#设置Atlas的运行方式,设为true时Atlas会启动两个进程,一个为monitor,一个为worker,monitor在worker意外退出后会自动将其重启,设为false时只有worker,没有monitor,一般开发调试时设为false,线上运行时设为true
keepalive = true
#工作线程数,对Atlas的性能有很大影响,可根据情况适当设置
event-threads = 10
#日志级别,分为message、warning、critical、error、debug五个级别
log-level = message
#日志存放的路径
log-path = /usr/local/mysql-proxy/log
#SQL日志的开关,可设置为OFF、ON、REALTIME,OFF代表不记录SQL日志,ON代表记录SQL日志,REALTIME代表记录SQL日志且实时写入磁盘,默认为OFF
#sql-log = OFF
#实例名称,用于同一台机器上多个Atlas实例间的区分
#instance = test
#Atlas监听的工作接口IP和端口
proxy-address = 0.0.0.0:1234
#Atlas监听的管理接口IP和端口
admin-address = 0.0.0.0:2345
#分表设置,此例中person为库名,mt为表名,id为分表字段,3为子表数量,可设置多项,以逗号分隔,若不分表则不需要设置该项
#tables = person.mt.id.3
#默认字符集,设置该项后客户端不再需要执行SET NAMES语句
#charset = utf8
#允许连接Atlas的客户端的IP,可以是精确IP,也可以是IP段,以逗号分隔,若不设置该项则允许所有IP连接,否则只允许列表中的IP连接
#client-ips = 127.0.0.1, 192.168.1
#Atlas前面挂接的LVS的物理网卡的IP(注意不是虚IP),若有LVS且设置了client-ips则此项必须设置,否则可以不设置
#lvs-ips = 192.168.1.1
5.启动数据节点(分别在三个数据节点上db169、db172、db173)
5.1 启动mysql数据库
5.2 启动atlas : /usr/local/mysql-proxy/bin/mysql-proxyd test start
5.3 启动lvs脚本: /etc/init/lvsdr.sh start
6.启动keepalived(db162、db163上)
/etc/init.d/keepalived start
7.验证:
启动keepalived后,主节点为db162,查看vip是不是启动了:
[root@db162 ~]# ip ad
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
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 00:1d:7d:a8:40:d9 brd ff:ff:ff:ff:ff:ff
inet 192.168.1.162/24 brd 192.168.1.255 scope global eth0
inet 192.168.1.201/32 scope global eth0
inet6 fe80::21d:7dff:fea8:40d9/64 scope link
valid_lft forever preferred_lft forever
验证此节点没有1234端口监听:
[root@db162 ~]# netstat -anp|grep 1234
此处无输出
在192.168.1.55(db55)上连接192.168.1.201(注意此节点没有1234端口在监听,发来的连接会被路由到真正的数据节点)
[root@db55 ~]# mysql -h 192.168.1.201 -P1234 -uroot -p123456
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 1871354501
Server version: 5.0.81-log Percona XtraDB Cluster binary (GPL) 5.6.19-25.6, Revision 824, wsrep_25.6.r4111
Copyright (c) 2000, 2014, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| dd |
| mcldb |
| mysql |
| mysqlslap |
| performance_schema |
| test |
+--------------------+
7 rows in set (0.00 sec)
数据是正确的
8.监控lvs
使用sysbench压力测试,然后监控线程分布:
[root@topdb soft]# sysbench --test=oltp --num-threads=100 --max-requests=100000 --oltp-table-size=1000000 --oltp-test-mode=nontrx --db-driver=mysql --mysql-db=dd --mysql-host=192.168.1.201 --mysql-port=1234 --mysql-user=root --mysql-password=123456 --oltp-nontrx-mode=select --oltp-read-only=on --db-ps-mode=disable run
sysbench 0.4.12: multi-threaded system evaluation benchmark
Running the test with following options:
Number of threads: 100
Doing OLTP test.
Running non-transactional test
Doing read-only test
Using Special distribution (12 iterations, 1 pct of values are returned in 75 pct cases)
Using "BEGIN" for starting transactions
Using auto_inc on the id column
Maximum number of requests for OLTP test is limited to 100000
Threads started!
Done.
OLTP test statistics:
queries performed:
read: 100033
write: 0
other: 0
total: 100033
transactions: 100033 (13416.81 per sec.)
deadlocks: 0 (0.00 per sec.)
read/write requests: 100033 (13416.81 per sec.)
other operations: 0 (0.00 per sec.)
Test execution summary:
total time: 7.4558s
total number of events: 100033
total time taken by event execution: 744.5136
per-request statistics:
min: 0.71ms
avg: 7.44ms
max: 407.23ms
approx. 95 percentile: 28.56ms
Threads fairness:
events (avg/stddev): 1000.3300/831.91
execution time (avg/stddev): 7.4451/0.00
[root@db162 ~]# ipvsadm -Ln
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
-> RemoteAddress:Port Forward Weight ActiveConn InActConn
TCP 192.168.1.201:1234 rr
-> 192.168.1.169:1234 Route 3 0 33
-> 192.168.1.172:1234 Route 3 0 34
-> 192.168.1.173:1234 Route 3 0 34
可以看出负载均衡在了三个节点。
另外可以自己关机测试下keepalived的故障转移。
注意点:
1.atlas和mysql数据节点要放在一台机器上,如果atlas在别处搭建,则lvs会无法使用。
2.keepavlied最好和数据节点不在同一台机器上,否则可能会有问题。
3.最好有真机测试,虚拟机上之前一直没捣鼓好。
4.keepalived配置最好根据示例文件修改,如果有空格、tab键不规范,可能造成无法争取读取配置,并且不给出错误提示。