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mysql高可用MHA+Atlas读写分离

2020-05-23 09:03:21  阅读:16  来源: 互联网

标签:10.0 slave MHA master mysql Atlas root


1、MySQL MHA介绍

  MHA ( Master High Availability )目前在MySQL高可用方面是一个相对成熟的解决方案 ,它由日本DeNA公司
youshimaton (现就职于Facebook公司)开发,是-套优秀的作为MySQL高可用性环境下故障切换和主从提升的高可用
软件。在MySQL故障切换过程中, MHA能做到在0~30秒之内自动完成数据库的故障切换操作,并且在进行故障切换的过
程中, MHA能在最大程度上保证数据的一致性,以达到真正意义上的高可用。
github地址: https://github.com/yoshinorim
**该软件由两部分组成: MHA Manager (管理节点)和MHA Node (数据节点)。**MHA Manager可以单独部署在一台
独立的机器上管理多个master-slave集群,也可以部署在一台slave节点 上。MHA Node运行在每台MySQL服务器上,
MHA Manager会定时探测集群中的master节点,当master出现故障时, 它可以自动将最新数据的slave提升为新的
master ,然后将所有其他的slave重新指向新的master。整个故障转移过程对应用程序完全透明。
在MHA自动故障切换过程中, MHA试图从宕机的主服务器上保存二进制日志 ,最大程度的保证数据的不丢失,但这并
不总是可行的。例如,如果主服务器硬件故障或无法通过ssh访问, MHA没法保存二进制日志 ,只进行故障转移而丢失了
最新的数据。**使用MySQL 5.5的半同步复制,可以大大降低数据丢失的风险。MHA可以与半同步复制结合起来。**如果只
有一个slave已经收到了最新的二进制日志, MHA可以将最新的二进制日志应用于其他所有的slave服务器.上,因此可以保
证所有节点的数据一致性。
目前MHA主要支持一主多从的架构,**要搭建MHA,要求一个复制集群中必须最少有三 台数据库服务器,**一主二从, 即一
台充当master ,一台充当备用master ,另外一台充当从库,因为至少需要三台服务器,出于机器成本的考虑,淘宝也在
该基础上进行了改造,目前淘宝TMHA已经支持一注- -从。(出自 :《深入浅出MySQL(第二版)》 )
官方介绍: https://code.google.com/p/mysql-master-ha/

下图展示了如何通过MHA Manager管理多组主从复制。

可以将MHA工作原理总结为如下:

(1 )从宕机崩溃的master保存:进制日志事件( binlog events );
(2)识别含有最新更新的slave ;
(3)应用差异的中继日志( relay log )到其他的slave ;
(4)应用从master保存的进制日志事件( binlog events) ;
(5)提升- -个slave为新的master ;
(6)使其他的slave连接新的masteri进行复制;

MHA软件由两部分组成, Manager工具包和Node工具包,具体的说明如下

Manager工具包主要包括以下几个工具:

masterha_ .check. ssh  #检查MHA的SSH配置状况
masterha .check. rep1  #检查MySQL复制状况
masterha manger  #启动MHA 
masterha_ .check_ status  #检测当前MHA运行状态
masterha master. .monitor  #检测master是否宕机
masterha master- switch  #控制故障转移(自动或者手动)
masterha .conf_ host  #添加或删余配置的server信息

Node工具包(这些工具通常由MHA Manager的脚本触发,无需人为操作)主要包括以下几个工具: .

save_ binary. _logs #保存和复制master的二进制日志
apply- diff. relay_logs #识别差异的中继日志事件并将其差异的事件应用于其他的slave
filter_ mysqlbinlog #去除不必要的ROLLBACK事件(MHA已不再使用这个工具)
purge. relay- .1ogs #清除中继日志(不会阻塞SQL线程)

2、安装部署

2.1、准备环境

主机名 内网ip 外网ip 角色
c81 10.0.0.81 172.16.1.81 master
c82 10.0.0.82 172.16.1.82 slave(备用master)
c83 10.0.0.83 172.16.1.83 slave
c84 10.0.0.84 172.16.1.84 mha+atlas
  10.0.0.89   VIP
1、同步时间,四台都做
echo "*/5 * * * * /usr/sbin/ntpdate ntp1.aliyun.com >/dev/null 2>&1">>/var/spool/cron/root

2、关闭防火墙和selinux,四台都做
systemctl stop firewalld.service #临时关闭
systemctl disable firewalld.service #永久关闭

setenforce 0 #临时关闭
sed -i  '/^SELINUX/s#enforcing#disabled#g' /etc/selinux/config #永久关闭

3、hosts解析,四台都做
cat >>/etc/hosts<<EOF
10.0.0.81 c81
10.0.0.82 c82
10.0.0.83 c83
10.0.0.84 c84
EOF

4、ssh免密登录,四台都做
#!/bin/bash
yum -y install sshpass &> /dev/null
read -p "请输入服务器密码:" passwd
UserName=root
IP="10.0.0."
#创建密钥
ssh-keygen -t dsa -f ~/.ssh/id_dsa -P "" &>/dev/null
#分发公钥
for i in 81 82 83 84  #这里的要改成自己机子的ip
  do
    sshpass -p "$passwd" ssh-copy-id -i ~/.ssh/id_dsa.pub -p 22 -o StrictHostKeyChecking=no $UserName@$IP$i &>/dev/null
done

2.2、配置mysql主从

2.2.1、安装yum repo

前三台装
wget http://repo.mysql.com/mysql-community-release-el7-5.noarch.rpm
rpm -ivh mysql-community-release-el7-5.noarch.rpm
yum install mysql-server mysql -y

第四台装
wget http://repo.mysql.com/mysql-community-release-el7-5.noarch.rpm
rpm -ivh mysql-community-release-el7-5.noarch.rpm
yum install mysql -y

2.2.2、启动mysql

前三台执行以下命令
1、启动mysql
systemctl start mysql

2、修改密码
update mysql.user set password=password('123456') where user='root' and host='localhost';
flush privileges;

3、配置主从
c81,master操作
server-id=1
log-bin=mysql-bin
#禁止mysql自动删除relaylog工能
relay_log_purge = 0
#mysql5.6已上的特性,开启gtid,必须主从全开
gtid_mode = on
enforce_gtid_consistency = 1
log_slave_updates = 1

c82,slave(备用master)操作
server-id=2
log-bin=mysql-bin
#禁止mysql自动删除relaylog工能
relay_log_purge = 0
#mysql5.6已上的特性,开启gtid,必须主从全开
gtid_mode = on
enforce_gtid_consistency = 1
log_slave_updates = 1

c83,slave操作
server-id=3
log-bin=mysql-bin
#禁止mysql自动删除relaylog工能
relay_log_purge = 0
#mysql5.6已上的特性,开启gtid,必须主从全开
gtid_mode = on
enforce_gtid_consistency = 1
log_slave_updates = 1

重启mysql
systemctl restart mysql

创建同步用户,三台都操作
grant replication slave on *.* to 'rep'@'10.0.0.%' identified by '123456';
flush privileges;

在c81,master操作
[root@c81 ~]# mysql -p123456

1、查看mysql主库的master状态
mysql> show master status\G
*************************** 1. row ***************************
             File: mysql-bin.000001
         Position: 530

mysql> show master status;
+------------------+----------+--------------+------------------+------------------------------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set                        |
+------------------+----------+--------------+------------------+------------------------------------------+
| mysql-bin.000001 |      530 |              |                  | e9a0b767-9c25-11ea-a267-000c29913c03:1-2 |
+------------------+----------+--------------+------------------+------------------------------------------+

2、查看GTID状态
mysql> show global variables like '%gtid%';
+---------------------------------+------------------------------------------+
| Variable_name                   | Value                                    |
+---------------------------------+------------------------------------------+
| binlog_gtid_simple_recovery     | OFF                                      |
| enforce_gtid_consistency        | ON                                       |
| gtid_executed                   | e9a0b767-9c25-11ea-a267-000c29913c03:1-2 |
| gtid_mode                       | ON                                       |
| gtid_owned                      |                                          |
| gtid_purged                     |                                          |
| simplified_binlog_gtid_recovery | OFF                                      |
+---------------------------------+------------------------------------------+

c82,slave(备用master)操作
[root@c82 ~]# mysql -p123456

1、关闭从服务器的复制功能
stop slave;

2、配置从服务器指向master
change master to master_host='10.0.0.81',master_user='rep',master_password='123456',master_log_file='mysql-bin.000001',master_log_pos==530;

3、开启从服务器的复制功能
start slave;

4、查看从服务器的复制功能状态
mysql> show slave status\G
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 10.0.0.81
                  Master_User: rep
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000001
          Read_Master_Log_Pos: 530
               Relay_Log_File: mysqld-relay-bin.000002
                Relay_Log_Pos: 314
        Relay_Master_Log_File: mysql-bin.000001
             Slave_IO_Running: Yes
            Slave_SQL_Running: Yes

c83,slave操作
[root@c83 ~]# mysql -p123456

1、关闭从服务器的复制功能
stop slave;

2、配置从服务器指向master
change master to master_host='10.0.0.81',master_user='rep',master_password='123456',master_log_file='mysql-bin.000001',master_log_pos==530;

3、开启从服务器的复制功能
start slave;

4、查看从服务器的复制功能状态
mysql> show slave status\G
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 10.0.0.81
                  Master_User: rep
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000001
          Read_Master_Log_Pos: 530
               Relay_Log_File: mysqld-relay-bin.000002
                Relay_Log_Pos: 314
        Relay_Master_Log_File: mysql-bin.000001
             Slave_IO_Running: Yes
            Slave_SQL_Running: Yes

2.3、安装MHA

2.3.1、安装依赖

四台机器都操作
yum install perl-DBD-MySQL -y
yum install -y perl-Config-Tiny epel-release perl-Log-Dispatch perl-Parallel-ForkManager perl-Time-HiRes

2.3.2、授权MHA管理用户

前三台操作
grant all privileges on *.* to mha@'10.0.0.%' identified by 'mha';
flush privileges;

2.3.3、安装MHA node节点

四台机器都操作
rpm -ivh mha4mysql-node-0.58-0.el7.centos.noarch.rpm

2.3.4、安装MHA 管理节点

注意:MHA管理节点不要装到mysql主库和切换的从库上(备用的主库),否则会在后面的vip无法漂移
[root@ c84 ~]# rpm -ivh mha4mysql-manager-0.58-0.el7.centos.noarch.rpm

2.3.5、配置MHA

[root@ c84 ~]# mkdir -p /etc/mha
[root@ c84 ~]# mkdir -p /var/log/mha/app1
[root@ c84 ~]# vim /etc/mha/app1.cnf

[server default]
manager_log=/var/log/mha/app1/manager.log
manager_workdir=/var/log/mha/app1
master_binlog_dir=/var/lib/mysql #binlog目录,如果说mysql的环境不一样,binlog位置不同,每台服务器的binlog的位置在server标签里面即可
user=mha
password=mha
ping_interval=2
repl_password=123456
repl_user=rep
ssh_user=root

[server1]
hostname=10.0.0.81
port=3306

[server2]
hostname=10.0.0.82
port=3306

[server3]
hostname=10.0.0.83
port=3306
ignore_fail=1 #如果这个节点挂了,mha将不可用,加上这个参数,slave挂了一样可以用
no_master=1 #从将这台主机转换为master
#candidate_master=1 #如果候选master有延迟的话,relay日志超过100m,failover切换不能成功,加上此参数后会忽略延迟日志大小。
#check_repl_delay=0 #用防止master故障时,切换slave时有延迟,卡在那切不过来

注意以上配置文件,添加时不能有空格和注释

2.3.6、启动测试

ssh检测

[root@ c84 ~]# masterha_check_ssh --conf=/etc/mha/app1.cnf

主从复制检测

[root@ c84 ~]# masterha_check_repl --conf=/etc/mha/app1.cnf

报错:

 需要在前三台的mysql配置文件中添加:

skip-name-resolve
#当然这个也可以直接在刚开始就添加进去

添加完需要重启mysql,重新配置主从

1、重启mysql
systemctl restart mysql

2、配置主从
2.1、master端
[root@81 ~]# mysql -p123456
mysql> show master status;
+------------------+----------+--------------+------------------+------------------------------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set                        |
+------------------+----------+--------------+------------------+------------------------------------------+
| mysql-bin.000004 |      191 |              |                  | ac342a62-9b2e-11ea-9c1b-000c29913c03:1-7 |
+------------------+----------+--------------+------------------+------------------------------------------+

2.2、slave(备用master)端
[root@c82 ~]# mysql -p123456
mysql> stop slave;
mysql> change master to master_host='10.0.0.81',master_user='rep',master_password='123456',master_log_file='mysql-bin.000004',master_log_pos=191;
mysql> start slave;
mysql> show slave status\G
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 10.0.0.81
                  Master_User: rep
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000004
          Read_Master_Log_Pos: 191
               Relay_Log_File: mysqld-relay-bin.000002
                Relay_Log_Pos: 314
        Relay_Master_Log_File: mysql-bin.000004
             Slave_IO_Running: Yes
            Slave_SQL_Running: Yes

2.3、slave端
[root@83 ~]# mysql -p123456
mysql> stop slave;
mysql> change master to master_host='10.0.0.81',master_user='rep',master_password='123456',master_log_file='mysql-bin.000004',master_log_pos=191;
mysql> start slave;
mysql> show slave status\G
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 10.0.0.81
                  Master_User: rep
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000004
          Read_Master_Log_Pos: 191
               Relay_Log_File: mysqld-relay-bin.000002
                Relay_Log_Pos: 314
        Relay_Master_Log_File: mysql-bin.000004
             Slave_IO_Running: Yes
            Slave_SQL_Running: Yes

再次主从复制检测

[root@ c84 ~]# masterha_check_repl --conf=/etc/mha/app1.cnf

成功

 

 

 2.3.7、启动MHA

[root@ c84 ~]# nohup masterha_manager --conf=/etc/mha/app1.cnf --remove_dead_master_conf --ignore_last_failover < /dev/null > /var/log/mha/app1/manager.log 2>&1 &

查看MHA状态

[root@ c84 ~]# masterha_check_status --conf=/etc/mha/app1.cnf
app1 (pid:18420) is running(0:PING_OK), master:10.0.0.81

2.3.8、测试MHA故障转移

1、停掉主c81主10.0.0.81
[root@ c81 ~]# systemctl stop mysql

2、查看c83的slave状态,发现master变成10.0.0.82
[root@ c83 ~]# mysql -uroot -p123456 -e "show slave status\G"
  
3、查看c82的master状态
[root@ c82 ~]# mysql -uroot -p123456 -e "show master status;"


4、查看c84的MHA配置文件

发生故障时,MHA做了什么?

①当作为主库的c7m01上的MySQL宕机以后,mha通过检测发现c7m01的mysql宕机了,那么会将binlog日志最全的从库(c702)立刻提升为主库,而其他的从库会指向新的主库进行再次同步。

②MHA会自己结束自己的进程,还会将/etc/mha/app1.cnf配置文件中,坏掉的那台机器剔除。

2.3.9、MHA故障还原

先将宕机mysql修复,然后加到mysql一主两从集群

1、[root@ c84 ~]# grep -i "CHANGE MASTER TO MASTER" /var/log/mha/app1/manager.log | tail -1
  Fri May 22 21:07:21 2020 - [info]  All other slaves should start replication from here. Statement should be: CHANGE MASTER TO MASTER_HOST='10.0.0.82', MASTER_PORT=3306, MASTER_AUTO_POSITION=1, MASTER_USER='rep', MASTER_PASSWORD='xxx';

2、启动c81的mysql
[root@ c81 ~]# systemctl start mysql

3、执行命令
[root@ c81 ~]# mysql -uroot -p123456 -e "CHANGE MASTER TO MASTER_HOST='10.0.0.82', MASTER_PORT=3306, MASTER_AUTO_POSITION=1, MASTER_USER='rep', MASTER_PASSWORD='123456';"

4、开启主从复制功能
[root@ c81 ~]# mysql -uroot -p123456 -e 'start slave;'

5、查看主从复制状态
[root@ c81 ~]# mysql -uroot -p123456 -e 'show slave status\G'



重新在将[server1]标签添加到MHA配置文件,并启动MHA
1、添加配置文件 [root@ c84 ~]# vim /etc/mha/app1.cnf [server1] hostname=10.0.0.81 port=3306 2、启动MHA [root@ c84 ~]# nohup masterha_manager --conf=/etc/mha/app1.cnf --remove_dead_master_conf --ignore_last_failover < /dev/null > /var/log/mha/app1/manager.log 2>&1 &

2.4、配置VIP漂移

2.4.1、VIP漂移的两种方式

  ①通过keepalived的方式,管理虚拟IP的漂移。
  ②通过MHA自带脚本的方式,管理虚拟IP的漂移#用mha自带的一 -个VIP漂移的脚本,哪个提升为主,就飘到那个上
面,要根据binlog最新的slave提升。

 2.4.2、MHA脚本方式

修改配置文件
[root@ c84 ~]# vim /etc/mha/app1.cnf
master_ip_failover_script=/usr/bin/master_ip_failover

编写漂移脚本master_ip_failover

注意:修改脚本中的网卡名和ip地址
[root@ c84 ~]# vim /usr/bin/master_ip_failover #!/usr/bin/env perl use strict; use warnings FATAL => 'all'; #!/usr/bin/env perl use strict; #!/usr/bin/env perl use strict; use warnings FATAL => 'all'; use Getopt::Long; my ( use strict; use warnings FATAL => 'all'; use strict; use warnings FATAL => 'all'; use Getopt::Long; my ( use Getopt::Long; use Getopt::Long; my ( $command, $ssh_user, $orig_master_host, $orig_master_ip, my ( $command, $ssh_user, $orig_master_host, $orig_master_ip, my ( my ( my ( $command, $ssh_user, $orig_master_host, $ori $command, $ssh_user, $orig_master_host, $ $command, $ssh_user, $orig_master_host, $orig_master_ip, $orig_master_port, $new_master_host, $new_master_ip, $new_master_port $orig_master_port, $new_master_host, $new_master_ip, $new_master_port ); ); my $vip = '10.0.0.89/24'; #!/usr/bin/env perl use strict; use warnings FATAL => 'all'; use Getopt::Long; my ( $command, $ssh_user, $orig_master_host, $orig_master_ip, $orig_master_port, $new_master_host, $new_master_ip, $new_master_port ); my $vip = '10.0.0.89/24'; my $key = '1'; my $ssh_start_vip = "/sbin/ifconfig ens33:$key $vip"; my $ssh_stop_vip = "/sbin/ifconfig ens33:$key down"; GetOptions( 'command=s' => \$command, 'ssh_user=s' => \$ssh_user, 'orig_master_host=s' => \$orig_master_host, 'orig_master_ip=s' => \$orig_master_ip, 'orig_master_port=i' => \$orig_master_port, 'new_master_host=s' => \$new_master_host, 'new_master_ip=s' => \$new_master_ip, 'new_master_port=i' => \$new_master_port, exit &main(); sub main { print "\n\nIN SCRIPT TEST====$ssh_stop_vip==$ssh_start_vip===\n\n"; if ( $command eq "stop" || $command eq "stopssh" ) { my $exit_code = 1; eval { print "Disabling the VIP on old master: $orig_master_host \n"; &stop_vip(); $exit_code = 0; }; if ($@) { warn "Got Error: $@\n"; exit $exit_code; } exit $exit_code; } elsif ( $command eq "start" ) { my $exit_code = 10; eval { print "Enabling the VIP - $vip on the new master - $new_master_host \n"; &start_vip(); $exit_code = 0; }; if ($@) { warn $@; exit $exit_code; } exit $exit_code; } elsif ( $command eq "status" ) { print "Checking the Status of the script.. OK \n"; exit 0; } else { &usage(); exit 1; } } sub start_vip() { `ssh $ssh_user\@$new_master_host \" $ssh_start_vip \"`; } sub stop_vip() { return 0 unless ($ssh_user); `ssh $ssh_user\@$orig_master_host \" $ssh_stop_vip \"`; } sub usage { print "Usage: master_ip_failover --command=start|stop|stopssh|status --orig_master_host=host --orig_master_ip=ip --orig_master_port=port --new_master_host=host --new_master_ip=ip --new_master_port=port\n"; }

给一个执行权限
[root@ c84 ~]# chmod +x /usr/bin/master_ip_failover

2.4.3、手动绑定VIP,在主库主机绑定

[root@ c82 ~]# ifconfig ens33:1 10.0.0.89
[root@ c82 ~]# ip addr show ens33
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 00:0c:29:23:1d:38 brd ff:ff:ff:ff:ff:ff
    inet 10.0.0.82/24 brd 10.0.0.255 scope global ens33
       valid_lft forever preferred_lft forever
    inet 10.0.0.89/8 brd 10.255.255.255 scope global ens33:1
       valid_lft forever preferred_lft forever
    inet6 fe80::20c:29ff:fe23:1d38/64 scope link
       valid_lft forever preferred_lft forever

2.4.4、重启MHA

[root@ c84 ~]# masterha_stop --conf=/etc/mha/app1.cnf
[root@ c84 ~]# nohup masterha_manager --conf=/etc/mha/app1.cnf --remove_dead_master_conf --ignore_last_failover < /dev/null > /var/log/mha/app1/manager.log 2>&1 &

2.4.5、查看MHA日志

[root@ c84 ~]# tail -f /var/log/mha/app1/manager.log

2.6、模拟主库宕机VIP漂移

[root@ c82 ~]# ifconfig ens33:1 10.0.0.89
[root@ c82 ~]# ip addr show ens33
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 00:0c:29:23:1d:38 brd ff:ff:ff:ff:ff:ff
    inet 10.0.0.82/24 brd 10.0.0.255 scope global ens33
       valid_lft forever preferred_lft forever
    inet 10.0.0.89/8 brd 10.255.255.255 scope global ens33:1
       valid_lft forever preferred_lft forever
    inet6 fe80::20c:29ff:fe23:1d38/64 scope link
       valid_lft forever preferred_lft forever


关闭c82的mysql
[root@ c82 ~]# systemctl stop mysql

注意可能会有几秒延迟
[root@ c82 ~]# ip addr show ens33
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 00:0c:29:23:1d:38 brd ff:ff:ff:ff:ff:ff
    inet 10.0.0.82/24 brd 10.0.0.255 scope global ens33
       valid_lft forever preferred_lft forever
    inet6 fe80::20c:29ff:fe23:1d38/64 scope link
       valid_lft forever preferred_lft forever

 查看c81上mysql的master状态和VIP

1、VIP
[root@ c81 ~]# ip addr show ens33
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 00:0c:29:91:3c:03 brd ff:ff:ff:ff:ff:ff
    inet 10.0.0.81/24 brd 10.0.0.255 scope global ens33
       valid_lft forever preferred_lft forever
    inet 10.0.0.89/24 brd 10.0.0.255 scope global secondary ens33:1
       valid_lft forever preferred_lft forever
    inet6 fe80::20c:29ff:fe91:3c03/64 scope link
       valid_lft forever preferred_lft forever

2、master状态
[root@ c81 ~]# mysql -uroot -p123456 -e 'show master status\G'
Warning: Using a password on the command line interface can be insecure.
*************************** 1. row ***************************
             File: mysql-bin.000002
         Position: 946
     Binlog_Do_DB:
 Binlog_Ignore_DB:
Executed_Gtid_Set: e9a0b767-9c25-11ea-a267-000c29913c03:1-4,
e9dc963a-9c25-11ea-a267-000c29231d38:1-4

3、Mysql之Atlas(读写分离)

数据库中间件Atlas与Mycat比较分库分表压测报告https://blog.csdn.net/izhitao/article/details/71680714

Atlas是由Qihoo 360公司Web平台部基础架构团队开发维护的一-个基于MySQL协议的数据中间层项目。它在MySQL言
方推出的MySQL-Proxy 0.8.2版本的基础上,修改了大量bug ,添加了很多功能特性。目前该项目在360公司内部得到了广
泛应用,很多MySQL业务已经接入了Atlas平台,每天承载的读写请求数达几十亿条。
源码Github : https://github.com/Qihoo360/Atlas

3.1、什么是读写分离

读写分离,基本的原理是让主数据库处理事务性增、删、改操作( INSERT. DELETE、 UPDATE ) , 而从数据库处理
SELECT查询操作。数据库复制把主数据库操作的变更同步到集群中的从数据库。

3.2、为什么读写分离.

因为数据库的“写" (写10000条数据到oracle可能要3分钟)操作是比较耗时的。但是数据库的“读" (从oracle读10000
条数据可能只要5秒钟)。所以读写分离,解决的是,数据库的写入,影响了查询的效率。

3.3、什么时候要读写分离

数据库不一定要读写分离,如果程序使用数据库较多时,而更新少,查询多的情况下会考虑使用,利用数据库主从同步
可以减少数据库压力,提高性能。当然,数据库也有其它优化方案。memcache 或是表折分,或是搜索引学。都是解
决方法。

3.4、Atlas的功用与应用场景

Atlas的功能有:
读写分离、从库负载均衡、自动分表、IP过滤、 SQL语句黑白名单、DBA可平滑上下线DB、自动摘除宕机的DB。

Atlas的使用场景:
Atlas是一个位于前端 应用与后端MySQL数据库之间的中间件,它使得应用程序员无需再关心读写分离、分表等与
MySQL相关的细节,可以专注于编写业务逻辑,同时使得DBA的运维工作对前端应用透明,上下线DB前端应用无感知。

3.5、 Atlas的安装过程

注意:
1、Atlas只能安装运行在64位的系统上
2、Centos 5.X安装Atlas-XX.el5.x86_ _64.rpm , Centos 6.X安装Atlas-XX.el6.x86 _64.rpm(经过测试centos7也可以使用6
的版本)
3、后端mysq|版本应大于5.1 ,建议使用Mysql 5.6以上

1、安装altas
[root@ c84 ~]# wget https://github.com/Qihoo360/Atlas/releases/download/2.2.1/Atlas-2.2.1.el6.x86_64.rpm
[root@ c84 ~]# rpm -ivh Atlas-2.2.1.el6.x86_64.rpm

2、修改配置文件
[root@ c84 ~]# cp /usr/local/mysql-proxy/conf/test.cnf{,.bak} #备份
[root@ c84 ~]# vim /usr/local/mysql-proxy/conf/test.cnf 全删,加上以下内容
[mysql-proxy]
admin-username = user
admin-password = pwd
proxy-backend-addresses = 10.0.0.89:3306 # 设置主库VIP的地址
proxy-read-only-backend-addresses = 10.0.0.82:3306,10.0.0.83:3306 #设置只读的从库地址
pwds = rep:/iZxz+0GRoA=,mha:O2jBXONX098= #设置数据库管理用户,加密方法:/usr/local/mysql-proxy/bin/encrypt 密码
daemon = true
keepalive = true
event-threads = 8
log-level = message
log-path = /usr/local/mysql-proxy/log
sql-log =ON
proxy-address = 0.0.0.0:1234
admin-address = 0.0.0.0:2345
charset = utf8

3、启动altas
#altas可以通过不同配置文件,同时启动多个Atlas代理多套MHA节点;
/usr/local/mysql-proxy/bin/mysql-proxyd test start #启动
/usr/local/mysql-proxy/bin/mysql-proxyd test stop #停止
/usr/local/mysql-proxy/bin/mysql-proxyd test restart #重启

启动成功
[root@ c84 ~]# /usr/local/mysql-proxy/bin/mysql-proxyd test start
OK: MySQL-Proxy of test is started
4、查看altas
ps -ef | grep mysql-proxy

3.6、Atlas读写分离

1、读测试
[root@ c84 ~]# mysql -umha -pmha -P1234 -h10.0.0.84
mysql> select @@server_id;
+-------------+
| @@server_id |
+-------------+
|           3 |
+-------------+
1 row in set (0.01 sec)

mysql> select @@server_id;
+-------------+
| @@server_id |
+-------------+
|           2 |
+-------------+
1 row in set (0.01 sec)

2、写测试
[root@ c84 ~]# mysql -umha -pmha -P1234 -h10.0.0.84
mysql> begin;select @@server_id;commit;
Query OK, 0 rows affected (0.01 sec)

+-------------+
| @@server_id |
+-------------+
|           1 |
+-------------+
1 row in set (0.00 sec)

Query OK, 0 rows affected (0.00 sec)

mysql> create database qq;
Query OK, 1 row affected (0.00 sec)

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| qq                 |
+--------------------+
4 rows in set (0.01 sec)

3.7、Atlas管理操作

1、登录管理接口
[root@ c84 ~]# mysql -uuser -ppwd -P2345 -h10.0.0.84

2、查看帮助信息
mysql> select * from help;
+----------------------------+---------------------------------------------------------+
| command                    | description                                             |
+----------------------------+---------------------------------------------------------+
| SELECT * FROM help         | shows this help                                         |
| SELECT * FROM backends     | lists the backends and their state                      |
| SET OFFLINE $backend_id    | offline backend server, $backend_id is backend_ndx's id |
| SET ONLINE $backend_id     | online backend server, ...                              |
| ADD MASTER $backend        | example: "add master 127.0.0.1:3306", ...               |
| ADD SLAVE $backend         | example: "add slave 127.0.0.1:3306", ...                |
| REMOVE BACKEND $backend_id | example: "remove backend 1", ...                        |
| SELECT * FROM clients      | lists the clients                                       |
| ADD CLIENT $client         | example: "add client 192.168.1.2", ...                  |
| REMOVE CLIENT $client      | example: "remove client 192.168.1.2", ...               |
| SELECT * FROM pwds         | lists the pwds                                          |
| ADD PWD $pwd               | example: "add pwd user:raw_password", ...               |
| ADD ENPWD $pwd             | example: "add enpwd user:encrypted_password", ...       |
| REMOVE PWD $pwd            | example: "remove pwd user", ...                         |
| SAVE CONFIG                | save the backends to config file                        |
| SELECT VERSION             | display the version of Atlas                            |
+----------------------------+---------------------------------------------------------+
16 rows in set (0.00 sec)

3、查看后端的代理库
mysql> SELECT * FROM backends;
+-------------+----------------+-------+------+
| backend_ndx | address        | state | type |
+-------------+----------------+-------+------+
|           1 | 10.0.0.89:3306 | up    | rw   |
|           2 | 10.0.0.82:3306 | up    | ro   |
|           3 | 10.0.0.83:3306 | up    | ro   |
+-------------+----------------+-------+------+
3 rows in set (0.00 sec)

4、下线后端节点
mysql> SET OFFLINE 3;
+-------------+----------------+---------+------+
| backend_ndx | address        | state   | type |
+-------------+----------------+---------+------+
|           3 | 10.0.0.83:3306 | offline | ro   |
+-------------+----------------+---------+------+
1 row in set (0.00 sec)

mysql> SELECT * FROM backends;
+-------------+----------------+---------+------+
| backend_ndx | address        | state   | type |
+-------------+----------------+---------+------+
|           1 | 10.0.0.89:3306 | up      | rw   |
|           2 | 10.0.0.82:3306 | up      | ro   |
|           3 | 10.0.0.83:3306 | offline | ro   |
+-------------+----------------+---------+------+
3 rows in set (0.00 sec)

5、上线后端节点
mysql> SET ONLINE 3;
+-------------+----------------+---------+------+
| backend_ndx | address        | state   | type |
+-------------+----------------+---------+------+
|           3 | 10.0.0.83:3306 | unknown | ro   |
+-------------+----------------+---------+------+
1 row in set (0.00 sec)

mysql> SELECT * FROM backends;
+-------------+----------------+-------+------+
| backend_ndx | address        | state | type |
+-------------+----------------+-------+------+
|           1 | 10.0.0.89:3306 | up    | rw   |
|           2 | 10.0.0.82:3306 | up    | ro   |
|           3 | 10.0.0.83:3306 | up    | ro   |
+-------------+----------------+-------+------+
3 rows in set (0.00 sec)

 



 

标签:10.0,slave,MHA,master,mysql,Atlas,root
来源: https://www.cnblogs.com/rm580036/p/12941022.html

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