目錄

一、概述

一、概念

二、組成

三、特點

四、工作原理

二、案例

三、構建MHA

一、基礎環境

二、ssh免密登錄

三、主從復制

master

slave1

四、MHA安裝

一、環境

二、安裝node

三、安裝manager

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一、概述

一、概念

????????MHA（MasterHigh Availability）是一套優秀的MySQL高可用環境下故障切換和主從復制的軟件。

????????MHA 的出現就是解決MySQL 單點的問題。

????????MySQL故障切換過程中，MHA能做到0-30秒內自動完成故障切換操作。

????????MHA能在故障切換的過程中最大程度上保證數據的一致性，以達到真正意義上的高可用。

二、組成

????????MHA manager????????????????管理節點

????????MHA node?????????????????????? 數據節點????????每個節點上都需要安裝

三、特點

????????自動故障切換過程中，MHA試圖從宕機的主服務器上保存二進制日志，最大程度的保證數據不丟失

????????使用半同步復制，可以大大降低數據丟失的風險，如果只有一個slave已經收到了最新的二進制日志，MHA可以將最新的二進制日志應用于其他所有的slave服務器上，因此可以保證所有節點的數據一致性

????????目前MHA支持一主多從架構，最少三臺服務，即一主兩從

四、工作原理

????????從宕機崩潰的master 保存二進制日志事件（binlog events）；
????????識別含有最新的更新slave日志
????????應用差異的中繼日志（relay log）到其他的slave
????????應用從master保存的二進制日志事件
????????提升一個slave為新的master
????????使其他的slave連接新的master進行復制

二、案例

????????192.168.100.3??? manager（MHA）? ? ?? ???? mgt
????????192.168.100.4??? master?? ???????????????????????????? master
????????192.168.100.5??? slave?? ??????????????????????? ? ? ??? slave1
????????192.168.100.6??? slave?? ????????????????????? ? ? ???? slave2

三、構建MHA

一、基礎環境

??????? 關閉防火墻

??????? 設置selinux寬容模式

??????? 配置靜態IP

????????????????????192.168.100.3??? manager（MHA）? ? ?? ???? mgt
??????????????????? 192.168.100.4??? master?? ???????????????????????????? master
??????????????????? 192.168.100.5??? slave?? ??????????????????????? ? ? ??? slave1
??????????????????? 192.168.100.6??? slave?? ????????????????????? ? ? ???? slave2

??????? 修改主機名

??????????????????? 192.168.100.3????? ????????????????????????? ?? ???? mgt
??????????????????? 192.168.100.4???????????????????????????????? master
??????????????????? 192.168.100.5???? ??????????????????????? ? ? ??? slave1
??????????????????? 192.168.100.6???? ????????????????????? ? ? ???? slave2

二、ssh免密登錄

????????

????????192.168.100.3
?????????????????? ?ssh-keygen
?????????????????? ?for i in 4 5 6;do ssh-copy-id root@192.168.100.$i;done

????????? 192.168.100.4
?????????????????? ?ssh-keygen
?????????????????? ?for i in 3 5 6;do ssh-copy-id root@192.168.100.$i;done

???????? 192.168.100.5
?????????????????? ?ssh-keygen
?????????????????? ?for i in 4 3 6;do ssh-copy-id root@192.168.100.$i;done

???????? 192.168.100.6
?????????????????? ?ssh-keygen
?????????????????? ?for i in 4 5 3;do ssh-copy-id root@192.168.100.$i;done

???????? 所有節點配置hosts?

??????????????????? vim /etc/hosts

???????????????????? for i in 4 5 6 ;do scp/etc/hosts 192.168.100.$i:/etc;done
?????????????????? ?192.168.100.3?? ?mgt
?????????????????? ?192.168.100.4?? ?master
?????????????????? ?192.168.100.5?? ?slave1
?????????????????? ?192.168.100.6?? ?slave2

???????? 測試
?????????????????? ?for i in 3 4 5;do ssh 192.168.100.$i ;done??????? （在192.168.100.3測試?? ）

???? ??????????????? for i in master slave1 slave2;do ssh $i ;done??

三、主從復制

master

????????vim? /etc/my.cnf
[mysqld]
server-id = 1
log-bin = master-bin
log-slave-updates = true

ystemctl restart mariadb
mysql -e "grant replication slave on *.* to 'myslave'@'192.168.100.%' identified by '123.com';"
mysql -e "grant all privileges on *.* to 'mha'@'192.168.100.%' identified by '123.com';"
mysql -e "grant all privileges on *.* to 'mha'@'192.168.100.3' identified by '123.com';"
mysql -e "grant all privileges on *.* to 'mha'@'192.168.100.5' identified by '123.com';"
mysql -e "grant all privileges on *.* to 'mha'@'192.168.100.6' identified by '123.com';"
mysql -e "show master status";

slave1

server-id=2
log-bin=master-bin
relay-log=relay-log-bin
relay-log-index=relay-log-bin.index

mysql -e "grant replication slave on *.* to 'myslave'@'192.168.100.%' identified by '123.com';"
mysql -e "grant all privileges on *.* to 'mha'@'192.168.100.%' identified by '123.com';"
mysql -e "grant all privileges on *.* to 'mha'@'192.168.100.3' identified by '123.com';"
mysql -e "grant all privileges on *.* to 'mha'@'192.168.100.4' identified by '123.com';"
mysql -e "grant all privileges on *.* to 'mha'@'192.168.100.6' identified by '123.com';"
mysql -e "change master to master_host='192.168.100.4',master_user='myslave',master_password='123.com',master_log_file='master-bin.000003',master_log_pos=1007;"

mysql -e “slave start”

slave2

server-id=3
log-bin=master-bin
relay-log=relay-log-bin
relay-log-index=relay-log-bin.index

??

mysql -e "grant replication slave on *.* to 'myslave'@'192.168.100.%' identified by '123.com';"
mysql -e "grant all privileges on *.* to 'mha'@'192.168.100.%' identified by '123.com';"
mysql -e "grant all privileges on *.* to 'mha'@'192.168.100.3' identified by '123.com';"
mysql -e "grant all privileges on *.* to 'mha'@'192.168.100.4' identified by '123.com';"
mysql -e "grant all privileges on *.* to 'mha'@'192.168.100.5' identified by '123.com';"
mysql -e "change master to master_host='192.168.100.4',master_user='myslave',master_password='123.com',master_log_file='master-bin.000003',master_log_pos=1007;"

mysql -e “slave start”

四、MHA安裝

一、環境

????????所有節點安裝perl環境

yum install epel-release -y &&yum install epel-release -y（第二次是更新）
yum -y install perl-DBD-MySQL perl-ExtUtils-MakeMaker perl-Config-Tiny perl-Log-Dispatch perl-Parallel-ForkManager perl-Time-HiRes perl-CPAN

二、安裝node

????????所有節點安裝node(已經下載的源碼包）

tar xf mha4mysql-node-0.57.tar.gz
cd mha4mysql-node-0.57
perl Makefile.PL && make && make install

????????cd /usr/local/bin??????? （發現存在文件）

yum install epel-release -y && yum install epel-release -y && yum -y install perl-DBD-MySQL perl-ExtUtils-MakeMaker perl-Config-Tiny perl-Log-Dispatch perl-Parallel-ForkManager perl-Time-HiRes perl-CPAN&&tar xf mha4mysql-node-0.57.tar.gz && cd mha4mysql-node-0.57 && perl Makefile.PL && make && make install && cd /usr/local/bin && ls

三、安裝manager

tar xf mha4mysql-manager-0.57.tar.gz
cd /root/mha4mysql-manager-0.57
perl Makefile.PL && make && make install
cp sample/scripts/master_ip_failover /usr/local/bin/
cp sample/scripts/master_ip_online_change?? ? /usr/local/bin/

cd /usr/local/bin?

vim??? master_ip_failover??

????????腳本說明(master_ip_failover)
?????????? ?master_ip_failover?? ?自動切換時 VIP 管理的腳本
?????????? ?master_ip_online_change?? ?在線切換時 vip 的管理
?????????? ?power_manager?? ?故障發生后關閉主機的腳本
?????????? ?send_report?? ?因故障切換后發送報警的腳本

配置文件建立
?????????? ?mkdir /etc/masterha
?????????? ?vim /etc/masterha/app1.cnf

????????mkdir /var/log/masterha/app1

測試MHA

?? masterha_check_ssh --conf=/etc/masterha/app1.cnf
?? ?masterha_check_repl --conf=/etc/masterha/app1.cnf

啟動

nohup masterha_manager --conf=/etc/masterha/app1.cnf --remove_dead_master_conf --ignore_last_failover < /dev/null > /var/log/masterha/app1/manager.log 2>&1 &

?此時master不顯示vip——ip

停止master后? slave1 會出現vip-ip

查看slave1狀態

?slave2

?實現MySQL高可用MHA