Mysql+Keepalived雙主熱備高可用操作步驟詳細解析
阿新 • • 發佈：2018-09-14
eve 腳本 server設置 not find 實驗 本地ip help oracle 查看 mysql+keepalived雙主熱備高可用的介紹：
我們通常說的雙機熱備是指兩臺機器都在運行，但並不是兩臺機器都同時在提供服務。當提供服務的一臺出現故障的時候，另外一臺會馬上自動接管並且提供服務，而且切換的時間非常短。MySQL雙主復制，即互為Master-Slave(只有一個Master提供寫操作)，可以實現數據庫服務器的熱備，但是一個Master宕機後不能實現動態切換。使用Keepalived，可以通過虛擬IP，實現雙主對外的統一接口以及自動檢查、失敗切換機制，從而實現MySQL數據庫的高可用方案。之前梳理了Mysql主從/主主同步，下面說下Mysql+keeoalived雙主熱備高可用方案的實施。
Keepalived看名字就知道，保持存活，在網絡裏面就是保持在線了，也就是所謂的高可用或熱備，用來防止單點故障（單點故障是指一旦某一點出現故障就會導 整個系統架構的不可用）的發生，那說到keepalived不得不說的一個協議不是VRRP協議，可以說這個協議就是keepalived實現的基礎。 1）Keepalived的工作原理是VRRP（Virtual Router Redundancy Protocol）虛擬路由冗余協議。在VRRP中有兩組重要的概念：VRRP路由器和虛擬路由器，主控路由器和備份路由器。 2）VRRP路由器是指運行VRRP的路由器，是物理實體，虛擬路由器是指VRRP協議創建的，是邏輯概念。一組VRRP路由器協同工作，共同構成一臺虛擬路由器。 Vrrp中存在著一種選舉機制，用以選出提供服務的路由即主控路由，其他的則成了備份路由。當主控路由失效後，備份路由中會重新選舉出一個主控路由，來繼 續工作，來保障不間斷服務。
實驗部署
實驗需求：
1）先實施Master->Slave的主主同步。主主是數據雙向同步，主從是數據單向同步。一般情況下，主庫宕機後，需要手動將連接切換到從庫上。（但是用keepalived就可以自動切換）
2）再結合Keepalived的使用，通過VIP實現Mysql雙主對外連接的統一接口。即客戶端通過Vip連接數據庫；當其中一臺宕機後，VIP會漂移到另一臺上，這個過程對於客戶端的數據連接來說幾乎無感覺，從而實現高可用。
實驗環境
| 服務角色 | ? ? ?IP | 系統及所需服務 |
|---|---|---|
| master1 | 192.168.24.128 | centos7 mysql keepalived |
| master2 | 192.168.24.130 | centos7 mysql keepalived |
| VIP | 192.168.24.188 |
註意：防火墻與SELINUX確保已經關閉
master1和master2同時按照mysql服務
博客中已有mysql的按照文檔，在此不再贅述
mysql主主同步環境部署
在master1 上操作如下
在my.cnf文件的[mysqld]配置區域添加下面內容：
[root@linfan ~]# vim /etc/my.cnf
[mysqld]
basedir = /usr/local/mysql
datadir = /opt/data
socket = /tmp/mysql.sock
port = 3306
pid-file = /opt/data/mysql.pid
user = mysql
skip-name-resolve
//添加以下內容
server-id = 1
log-bin = mysql-bin
sync_binlog = 1
binlog_checksum = none
binlog_format = mixed
auto-increment-increment = 2
auto-increment-offset = 1
slave-skip-errors = all 重啟mysql服務
[root@linfan ~]# service mysqld restart
Shutting down MySQL.. SUCCESS!
Starting MySQL.. SUCCESS! 數據同步授權，這樣I/O線程就可以以這個用戶的身份連接到主服務器，並且讀取它的二進制日誌。
mysql> grant replication slave,replication client on *.* to doudou@‘192.168.24.%‘ identified by "123456";
Query OK, 0 rows affected, 1 warning (0.01 sec)
mysql> flush privileges;
//刷新權限
Query OK, 0 rows affected (0.00 sec)
mysql> flush tables with read lock;
//最好將庫鎖住，僅僅允許讀，以保證數據一致性；待主主同步環境部署後再解鎖；
鎖住後，就不能往表裏寫數據，但是重啟mysql服務後就會自動解鎖！
Query OK, 0 rows affected (0.00 sec)
mysql> show master status;
//log bin日誌和pos值位置
+------------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+-------------------+
| mysql-bin.000001 | 612 | | | |
+------------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)在master2 上操作如下
在my.cnf文件的[mysqld]配置區域添加下面內容：
[root@linfan ~]# vim /etc/my.cnf
[mysqld]
basedir = /usr/local/mysql
datadir = /opt/data
socket = /tmp/mysql.sock
port = 3306
pid-file = /opt/data/mysql.pid
user = mysql
skip-name-resolve
//添加以下內容
server-id = 2
log-bin = mysql-bin
sync_binlog = 1
binlog_checksum = none
binlog_format = mixed
auto-increment-increment = 2
auto-increment-offset = 2
slave-skip-errors = all 重啟mysql的服務
[root@linfan ~]# service mysqld restart
Shutting down MySQL.. SUCCESS!
Starting MySQL... SUCCESS! 數據同步授權，這樣I/O線程就可以以這個用戶的身份連接到主服務器，並且讀取它的二進制日誌。
mysql> grant replication slave,replication client on *.* to doudou@‘192.168.24.%‘ identified by "123456";
Query OK, 0 rows affected, 1 warning (0.00 sec)
mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)
mysql> flush tables with read lock;
Query OK, 0 rows affected (0.00 sec)
mysql> show master status;
+------------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+-------------------+
| mysql-bin.000004 | 150 | | | |
+------------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)在master1上做同步操作
mysql> unlock tables; //先解鎖，將對方數據同步到自己的數據庫中
mysql> stop slave;
mysql> change master to master_host=‘192.168.24.130‘,master_user=‘doudou‘,master_password=‘123456‘,master_log_file=‘mysql-bin.000004‘,master_log_pos=150;
Query OK, 0 rows affected, 2 warnings (0.01 sec)
mysql> start slave;
Query OK, 0 rows affected (0.01 sec)
查看同步狀態，如下出現兩個“Yes”，表明同步成功！
mysql> show slave status\G;
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 192.168.24.130
Master_User: doudou
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin.000004
Read_Master_Log_Pos: 150
Relay_Log_File: linfan-relay-bin.000002
Relay_Log_Pos: 312
Relay_Master_Log_File: mysql-bin.000004
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
Replicate_Do_DB:
Replicate_Ignore_DB:
Replicate_Do_Table:
Replicate_Ignore_Table:
Replicate_Wild_Do_Table:
Replicate_Wild_Ignore_Table:
Last_Errno: 0
Last_Error:
Skip_Counter: 0
Exec_Master_Log_Pos: 150
Relay_Log_Space: 512
Until_Condition: None
Until_Log_File:
Until_Log_Pos: 0
Master_SSL_Allowed: No
Master_SSL_CA_File:
Master_SSL_CA_Path:
Master_SSL_Cert:
Master_SSL_Cipher:
Master_SSL_Key:
Seconds_Behind_Master: 0
Master_SSL_Verify_Server_Cert: No
Last_IO_Errno: 0
Last_IO_Error:
Last_SQL_Errno: 0
Last_SQL_Error:
Replicate_Ignore_Server_Ids:
Master_Server_Id: 2
Master_UUID: dc702f48-b7b9-11e8-9caa-000c298fc02c
Master_Info_File: /opt/data/master.info
SQL_Delay: 0
SQL_Remaining_Delay: NULL
Slave_SQL_Running_State: Slave has read all relay log; waiting for more updates
Master_Retry_Count: 86400
Master_Bind:
Last_IO_Error_Timestamp:
Last_SQL_Error_Timestamp:
Master_SSL_Crl:
Master_SSL_Crlpath:
Retrieved_Gtid_Set:
Executed_Gtid_Set:
Auto_Position: 0
Replicate_Rewrite_DB:
Channel_Name:
Master_TLS_Version:
1 row in set (0.00 sec)
ERROR:
No query specified
在master2上做同步操作：
mysql> unlock tables; //先解鎖，將對方數據同步到自己的數據庫中
mysql> stop slave;
mysql> change master to master_host=‘192.168.24.129‘,master_user=‘doudou‘,master_password=‘123456‘,master_log_file=‘mysql-bin.000001‘,master_log_pos=612;
Query OK, 0 rows affected, 2 warnings (0.01 sec)
mysql> start slave;
Query OK, 0 rows affected (0.01 sec)
查看同步狀態，如下出現兩個“Yes”，表明同步成功！
mysql> show slave status\G;
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 192.168.24.130
Master_User: doudou
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin.000001
Read_Master_Log_Pos: 150
Relay_Log_File: linfan-relay-bin.000002
Relay_Log_Pos: 312
Relay_Master_Log_File: mysql-bin.000001
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
Replicate_Do_DB:
Replicate_Ignore_DB:
Replicate_Do_Table:
Replicate_Ignore_Table:
Replicate_Wild_Do_Table:
Replicate_Wild_Ignore_Table:
Last_Errno: 0
Last_Error:
Skip_Counter: 0
Exec_Master_Log_Pos: 150
Relay_Log_Space: 512
Until_Condition: None
Until_Log_File:
Until_Log_Pos: 0
Master_SSL_Allowed: No
Master_SSL_CA_File:
Master_SSL_CA_Path:
Master_SSL_Cert:
Master_SSL_Cipher:
Master_SSL_Key:
Seconds_Behind_Master: 0
Master_SSL_Verify_Server_Cert: No
Last_IO_Errno: 0
Last_IO_Error:
Last_SQL_Errno: 0
Last_SQL_Error:
Replicate_Ignore_Server_Ids:
Master_Server_Id: 2
Master_UUID: dc702f48-b7b9-11e8-9caa-000c298fc02c
Master_Info_File: /opt/data/master.info
SQL_Delay: 0
SQL_Remaining_Delay: NULL
Slave_SQL_Running_State: Slave has read all relay log; waiting for more updates
Master_Retry_Count: 86400
Master_Bind:
Last_IO_Error_Timestamp:
Last_SQL_Error_Timestamp:
Master_SSL_Crl:
Master_SSL_Crlpath:
Retrieved_Gtid_Set:
Executed_Gtid_Set:
Auto_Position: 0
Replicate_Rewrite_DB:
Channel_Name:
Master_TLS_Version:
1 row in set (0.00 sec)
ERROR:
No query specified
PS： 在這裏可能會報錯
Got fatal error 1236 from master when reading data from binary log: ‘Could not find first log file name in binary log index file‘突然之間Slave_IO_Running: 狀態變成NO了
解決方法。
首先在從庫上執行
stop slave;
查看主庫master狀態
mysql> show master status\G;
*************************** 1. row ***************************
File: mysql-bin.000113
Position: 276925387
Binlog_Do_DB:
Binlog_Ignore_DB:
Executed_Gtid_Set:
1 row in set (0.00 sec)
ERROR:
No query specified
mysql> flush logs;
Query OK, 0 rows affected (0.11 sec)刷新binlog日誌
flush logs;
刷新後的日誌會+1
例如上面的 File: mysql-bin.000113 會變成 File: mysql-bin.000114
再次查看master狀態
mysql> show master status\G;
*************************** 1. row ***************************
File: mysql-bin.000114
Position: 120
Binlog_Do_DB:
Binlog_Ignore_DB:
Executed_Gtid_Set:
1 row in set (0.00 sec)
ERROR:
No query specified然後就不需要在操作master，切換到從庫
輸入CHANGE MASTER TO MASTER_LOG_FILE=‘mysql-bin.000114‘,MASTER_LOG_POS=120;
執行start slave;
查看從庫狀態
mysql> show slave status\G;
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 101.200.*.*
Master_User: backup
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin.000114
Read_Master_Log_Pos: 11314
Relay_Log_File: mysql-relay.000002
Relay_Log_Pos: 11477
Relay_Master_Log_File: mysql-bin.000114
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
Replicate_Do_DB:
Replicate_Ignore_DB:
Replicate_Do_Table:
Replicate_Ignore_Table:
Replicate_Wild_Do_Table:
Replicate_Wild_Ignore_Table:
Last_Errno: 0
Last_Error:
Skip_Counter: 0
Exec_Master_Log_Pos: 11314
Relay_Log_Space: 11646
Until_Condition: None
Until_Log_File:
Until_Log_Pos: 0
Master_SSL_Allowed: No
Master_SSL_CA_File:
Master_SSL_CA_Path:
Master_SSL_Cert:
Master_SSL_Cipher:
Master_SSL_Key:
Seconds_Behind_Master: 0
Master_SSL_Verify_Server_Cert: No
Last_IO_Errno: 0
Last_IO_Error:
Last_SQL_Errno: 0
Last_SQL_Error:
Replicate_Ignore_Server_Ids:
Master_Server_Id: 21
Master_UUID: e4a43da7-5b58-11e5-a12f-00163e003632
Master_Info_File: /home/data/mysql/master.info
SQL_Delay: 0
SQL_Remaining_Delay: NULL
Slave_SQL_Running_State: Slave has read all relay log; waiting for the slave I/O thread to update it
Master_Retry_Count: 86400
Master_Bind:
Last_IO_Error_Timestamp:
Last_SQL_Error_Timestamp:
Master_SSL_Crl:
Master_SSL_Crlpath:
Retrieved_Gtid_Set:
Executed_Gtid_Set:
Auto_Position: 0
1 row in set (0.00 sec)
ERROR:
No query specified主主同步效果驗證
1）在master1服務器的數據庫寫入數據：
mysql> create database tom;
Query OK, 1 row affected (0.01 sec)
mysql> use tom;
Database changed
mysql> create table mary(id int,name varchar(100) not null,age tinyint);
Query OK, 0 rows affected (0.06 sec)
mysql> insert mary values(1,"lisi",10),(2,"zhangshan",28),(3,"wangwu",18);
Query OK, 3 rows affected (0.11 sec)
Records: 3 Duplicates: 0 Warnings: 0
mysql> select * from mary;
+------+-----------+------+
| id | name | age |
+------+-----------+------+
| 1 | lisi | 10 |
| 2 | zhangshan | 28 |
| 3 | wangwu | 18 |
+------+-----------+------+
3 rows in set (0.00 sec)
然後在master2數據庫上查看，發現數據已經同步過來了!
mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| performance_schema |
| sys |
| tom |
+--------------------+
5 rows in set (0.01 sec)
mysql> use tom;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
Database changed
mysql> show tables;
+---------------+
| Tables_in_tom |
+---------------+
| mary |
+---------------+
1 row in set (0.00 sec)
mysql> select * from mary;
+------+-----------+------+
| id | name | age |
+------+-----------+------+
| 1 | lisi | 10 |
| 2 | zhangshan | 28 |
| 3 | wangwu | 18 |
+------+-----------+------+
3 rows in set (0.00 sec)2）在master2數據庫上寫入新數據
mysql> insert mary values(4,"zhaosi",66),(5,"lida",88);
Query OK, 2 rows affected (0.01 sec)
Records: 2 Duplicates: 0 Warnings: 0
mysql> select * from mary;
+------+-----------+------+
| id | name | age |
+------+-----------+------+
| 1 | lisi | 10 |
| 2 | zhangshan | 28 |
| 3 | wangwu | 18 |
| 4 | zhaosi | 66 |
| 5 | lida | 88 |
+------+-----------+------+
5 rows in set (0.00 sec)然後在master1數據庫上查看，發現數據也已經同步過來了!
mysql> select * from mary;
+------+-----------+------+
| id | name | age |
+------+-----------+------+
| 1 | lisi | 10 |
| 2 | zhangshan | 28 |
| 3 | wangwu | 18 |
| 4 | zhaosi | 66 |
| 5 | lida | 88 |
+------+-----------+------+
5 rows in set (0.00 sec)
至此，Mysql主主同步環境已經實現。
配置Mysql+Keepalived故障轉移的高可用環境
安裝keepalived並將其配置成系統服務。master1和master2兩臺機器上同樣進行如下操作：
[root@linfan ~]# yum install -y openssl-devel
[root@linfan ~]# cd /usr/src/
[root@linfan src]# wget http://www.keepalived.org/software/keepalived-1.3.5.tar.gz
[root@linfan src]# tar -xf keepalived-1.3.5.tar.gz
[root@linfan src]# cd keepalived-1.3.5
[root@linfan keepalived-1.3.5]# ./configure --prefix=/usr/local/keepalived
//此處會有警告提示，忽略即可！
[root@linfan keepalived-1.3.5]# make && make install
[root@linfan keepalived-1.3.5]# cp /usr/src/keepalived-1.3.5/keepalived/etc/init.d/keepalived /etc/rc.d/init.d/
[root@linfan keepalived-1.3.5]# cp /usr/local/keepalived/etc/sysconfig/keepalived /etc/sysconfig/
[root@linfan keepalived-1.3.5]# mkdir /etc/keepalived/
[root@linfan keepalived-1.3.5]# cp /usr/local/keepalived/etc/keepalived/keepalived.conf /etc/keepalived/
[root@linfan keepalived-1.3.5]# cp /usr/local/keepalived/sbin/keepalived /usr/sbin/
[root@linfan keepalived-1.3.5]# echo "/etc/init.d/keepalived start" >> /etc/rc.local
2）master1機器上的keepalived.conf配置。（下面配置中沒有使用lvs的負載均衡功能，所以不需要配置虛擬服務器virtual server）
[root@linfan ~]# cp /etc/keepalived/keepalived.conf /etc/keepalived/keepalived.conf.bak
[root@linfan ~]# vim /etc/keepalived/keepalived.conf //清空內容，添加為以下內容
! Configuration File for keepalived
global_defs {
notification_email {
[email protected]
[email protected]
}
notification_email_from [email protected]
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id MASTER-HA
}
vrrp_script chk_mysql_port { #檢測mysql服務是否在運行。有很多方式，比如進程，用腳本檢測等等
script "/opt/chk_mysql.sh" #這裏通過腳本監測
interval 2 #腳本執行間隔，每2s檢測一次
weight -5 #腳本結果導致的優先級變更，檢測失敗（腳本返回非0）則優先級 -5
fall 2 #檢測連續2次失敗才算確定是真失敗。會用weight減少優先級（1-255之間）
rise 1 #檢測1次成功就算成功。但不修改優先級
}
vrrp_instance VI_1 {
state MASTER
interface eth0 #指定虛擬ip的網卡接口
mcast_src_ip 192.168.24.128
virtual_router_id 51 #路由器標識，MASTER和BACKUP必須是一致的
priority 101 #定義優先級，數字越大，優先級越高，在同一個vrrp_instance下，MASTER的優先級必須大於BACKUP的優先級。
這樣MASTER故障恢復後，就可以將VIP資源再次搶回來
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.24.188
}
track_script {
chk_mysql_port
}
}編寫切換腳本。KeepAlived做心跳檢測，如果Master的MySQL服務掛了(3306端口掛了),那麽它就會選擇自殺。Slave的KeepAlived通過心跳檢測發現這個情況，就會將VIP的請求接管
vim /opt/chk_mysql.sh
#!/bin/bash
counter=$(netstat -na|grep "LISTEN"|grep "3306"|wc -l)
if [ "${counter}" -eq 0 ]; then
/etc/init.d/keepalived stop
fi
[root@linfan ~]# chmod 755 /opt/chk_mysql.sh
[root@linfan ~]# /etc/init.d/keepalived start
Starting keepalived (via systemctl): Job for keepalived.service failed because a timeout was exceeded. See "systemctl status keepalived.service" and "journalctl -xe" for details.
[FAILED]
//發現啟動失敗。經排查，是因為pid的路徑有問題
vim /lib/systemd/system/keepalived.service
[Unit]
Description=LVS and VRRP High Availability Monitor
After=syslog.target network-online.target
[Service]
Type=forking
PIDFile=/var/run/keepalived.pid //將此行修改如此
KillMode=process
EnvironmentFile=-/usr/local/keepalived/etc/sysconfig/keepalived
ExecStart=/usr/local/keepalived/sbin/keepalived $KEEPALIVED_OPTIONS
ExecReload=/bin/kill -HUP $MAINPID
[Install]
WantedBy=multi-user.target
[root@linfan ~]# systemctl daemon-reload //重新載入 systemd，掃描新的或有變動的單元
再次啟動
[root@linfan ~]# /etc/init.d/keepalived start
Starting keepalived (via systemctl): [ OK ]
4）master2機器上的keepalived配置。master2機器上的keepalived.conf文件只修改priority為90、nopreempt不設置、real_server設置本地IP。
[root@linfan ~]# cp /etc/keepalived/keepalived.conf /etc/keepalived/keepalived.conf.bak
[root@linfan ~]# vim /etc/keepalived/keepalived.conf //清空內容，添加為以下內容
! Configuration File for keepalived
global_defs {
notification_email {
[email protected]
[email protected]
}
notification_email_from [email protected]
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id MASTER-HA
}
vrrp_script chk_mysql_port {
script "/opt/chk_mysql.sh"
interval 2
weight -5
fall 2
rise 1
}
vrrp_instance VI_1 {
state BACKUP
interface eth0
mcast_src_ip 192.168.24.130 //本機IP
virtual_router_id 51
priority 99
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.24.188 //VIP
}
track_script {
chk_mysql_port
}
}
vim /opt/chk_mysql.sh //編寫腳本
#!/bin/bash
counter=$(netstat -na|grep "LISTEN"|grep "3306"|wc -l)
if [ "${counter}" -eq 0 ]; then
/etc/init.d/keepalived stop
fi
//為了避免再次啟動失敗，在此提前修改
vim /lib/systemd/system/keepalived.service
[Unit]
Description=LVS and VRRP High Availability Monitor
After=syslog.target network-online.target
[Service]
Type=forking
PIDFile=/var/run/keepalived.pid //將此行修改如此
KillMode=process
EnvironmentFile=-/usr/local/keepalived/etc/sysconfig/keepalived
ExecStart=/usr/local/keepalived/sbin/keepalived $KEEPALIVED_OPTIONS
ExecReload=/bin/kill -HUP $MAINPID
[Install]
WantedBy=multi-user.target
[root@linfan ~]# systemctl daemon-reload //重新載入 systemd，掃描新的或有變動的單元
啟動
[root@linfan ~]# /etc/init.d/keepalived start
Starting keepalived (via systemctl): [ OK ]
5）master1和master2兩臺服務器都要授權允許root用戶遠程登錄，用於在客戶端登陸測試！
mysql> grant all on *.* to root@‘%‘ identified by "123456";
Query OK, 0 rows affected, 1 warning (0.02 sec)
mysql> flush privileges;
Query OK, 0 rows affected (0.01 sec)Mysql＋keepalived故障轉移的高可用測試
1）通過Mysql客戶端通過VIP連接，看是否連接成功。
比如，在遠程一臺測試機上連接，通過vip地址可以正常連接（下面的連接權限要是在服務端提前授權的）
[root@linfan ~]# mysql -h192.168.24.188 -uroot -p123456
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 7
Server version: 5.7.22-log MySQL Community Server (GPL)
Copyright (c) 2000, 2018, 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> select * from tom.mary;
+------+-----------+------+
| id | name | age |
+------+-----------+------+
| 1 | lisi | 10 |
| 2 | zhangshan | 28 |
| 3 | wangwu | 18 |
| 4 | zhaosi | 66 |
| 5 | lida | 88 |
+------+-----------+------+
5 rows in set (0.00 sec)2）默認情況下，vip是在master1上的。使用"ip addr"命令查看vip切換情況
[root@linfan ~]# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
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 00:0c:29:23:40:f6 brd ff:ff:ff:ff:ff:ff
inet 192.168.24.128/24 brd 192.168.24.255 scope global eth0
valid_lft forever preferred_lft forever
inet 192.168.24.188/32 scope global eth0
valid_lft forever preferred_lft forever ////這個32位子網掩碼的vip地址表示該資源目前還在master1機器上
inet 192.168.24.146/24 brd 192.168.24.255 scope global secondary dynamic eth0
valid_lft 1115sec preferred_lft 1115sec
inet6 fe80::20c:29ff:fe23:40f6/64 scope link
valid_lft forever preferred_lft forever停止master1機器上的mysql服務，根據配置中的腳本，mysql服務停了，keepalived也會停，從而vip資源將會切換到master2機器上。（mysql服務沒有起來的時候，keepalived服務也無法順利啟動！）
[root@linfan ~]# service mysqld stop
Shutting down MySQL............ SUCCESS!
[root@linfan ~]# ps -ef|grep mysql
root 10652 2175 0 03:04 pts/1 00:00:00 grep --color=auto mysql
[root@linfan ~]# ps -ef|grep keepalived
root 10654 2175 0 03:04 pts/1 00:00:00 grep --color=auto keepalived
[root@linfan ~]# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
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 00:0c:29:23:40:f6 brd ff:ff:ff:ff:ff:ff
inet 192.168.24.128/24 brd 192.168.24.255 scope global eth0
valid_lft forever preferred_lft forever
inet 192.168.24.146/24 brd 192.168.24.255 scope global secondary dynamic eth0
valid_lft 998sec preferred_lft 998sec
inet6 fe80::20c:29ff:fe23:40f6/64 scope link
valid_lft forever preferred_lft forever如上結果，發現32位子網掩碼的vip沒有了，說明此時vip資源已不在master1機器上了
查看下master1的系統日誌，如下，會發現vip資源已經切換走了
[root@linfan ~]# tail -f /var/log/messages
Sep 14 03:03:54 linfan systemd: Stopping LVS and VRRP High Availability Monitor...
Sep 14 03:03:54 linfan Keepalived_vrrp[6871]: VRRP_Instance(VI_1) sent 0 priority
Sep 14 03:03:54 linfan Keepalived_vrrp[6871]: VRRP_Instance(VI_1) removing protocol VIPs.
Sep 14 03:03:54 linfan Keepalived_healthcheckers[6869]: Stopped
Sep 14 03:03:55 linfan Keepalived_vrrp[6871]: Stopped
Sep 14 03:03:55 linfan Keepalived[6868]: Stopped Keepalived v1.3.5 (03/19,2017), git commit v1.3.5-6-g6fa32f2
Sep 14 03:03:55 linfan systemd: Stopped LVS and VRRP High Availability Monitor.
Sep 14 03:04:55 linfan dhclient[3177]: DHCPREQUEST on eth0 to 192.168.24.254 port 67 (xid=0x7f91b51f)
Sep 14 03:04:55 linfan dhclient[3177]: DHCPACK from 192.168.24.254 (xid=0x7f91b51f)
Sep 14 03:04:57 linfan dhclient[3177]: bound to 192.168.24.146 -- renewal in 829 seconds.再到master2機器上，發現vip資源的確切換過來了
[root@linfan ~]# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
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 00:0c:29:8f:c0:2c brd ff:ff:ff:ff:ff:ff
inet 192.168.24.130/24 brd 192.168.24.255 scope global eth0
valid_lft forever preferred_lft forever
inet 192.168.24.188/32 scope global eth0
valid_lft forever preferred_lft forever
inet6 fe80::20c:29ff:fe8f:c02c/64 scope link
valid_lft forever preferred_lft forever查看master2的系統日誌
[root@linfan ~]# tail -f /var/log/messages
Sep 14 03:12:19 linfan Keepalived_vrrp[6710]: Sending gratuitous ARP on eth0 for 192.168.24.188
Sep 14 03:12:19 linfan Keepalived_vrrp[6710]: Sending gratuitous ARP on eth0 for 192.168.24.188
Sep 14 03:12:19 linfan Keepalived_vrrp[6710]: Sending gratuitous ARP on eth0 for 192.168.24.188
Sep 14 03:12:19 linfan Keepalived_vrrp[6710]: Sending gratuitous ARP on eth0 for 192.168.24.188
Sep 14 03:12:24 linfan Keepalived_vrrp[6710]: Sending gratuitous ARP on eth0 for 192.168.24.188
Sep 14 03:12:24 linfan Keepalived_vrrp[6710]: VRRP_Instance(VI_1) Sending/queueing gratuitous ARPs on eth0 for 192.168.24.188
Sep 14 03:12:24 linfan Keepalived_vrrp[6710]: Sending gratuitous ARP on eth0 for 192.168.24.188
Sep 14 03:12:24 linfan Keepalived_vrrp[6710]: Sending gratuitous ARP on eth0 for 192.168.24.188
Sep 14 03:12:24 linfan Keepalived_vrrp[6710]: Sending gratuitous ARP on eth0 for 192.168.24.188
Sep 14 03:12:24 linfan Keepalived_vrrp[6710]: Sending gratuitous ARP on eth0 for 192.168.24.188
3）再次啟動master1的mysql和keepalived服務。（註意：如果restart重啟mysql，那麽還要啟動下keepalived，因為mysql重啟，根據腳本會造成keepalived關閉）
註意：一定要先啟動mysql服務，然後再啟動keepalived服務。如果先啟動keepalived服務，按照上面的配置，mysql沒有起來，就會自動關閉keepalived。
[root@linfan ~]# service mysqld start
Starting MySQL.. SUCCESS!
[root@linfan ~]# /etc/init.d/keepalived start
Starting keepalived (via systemctl): [ OK ]
啟動這兩個服務器後，稍微等過一會兒，註意觀察會發現vip資源再次從master2機器上切換回來了。
[root@linfan ~]# ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
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 00:0c:29:23:40:f6 brd ff:ff:ff:ff:ff:ff
inet 192.168.24.128/24 brd 192.168.24.255 scope global eth0
valid_lft forever preferred_lft forever
inet 192.168.24.188/32 scope global eth0
valid_lft forever preferred_lft forever
inet 192.168.24.146/24 brd 192.168.24.255 scope global secondary dynamic eth0
valid_lft 1587sec preferred_lft 1587sec
inet6 fe80::20c:29ff:fe23:40f6/64 scope link
valid_lft forever preferred_lft forever
[root@linfan ~]# tail -f /var/log/messages
Sep 14 03:08:26 linfan Keepalived_vrrp[11028]: Sending gratuitous ARP on eth0 for 192.168.24.188
Sep 14 03:08:26 linfan Keepalived_vrrp[11028]: Sending gratuitous ARP on eth0 for 192.168.24.188
Sep 14 03:08:26 linfan Keepalived_vrrp[11028]: Sending gratuitous ARP on eth0 for 192.168.24.188
Sep 14 03:08:26 linfan Keepalived_vrrp[11028]: Sending gratuitous ARP on eth0 for 192.168.24.188
Sep 14 03:08:31 linfan Keepalived_vrrp[11028]: Sending gratuitous ARP on eth0 for 192.168.24.188
Sep 14 03:08:31 linfan Keepalived_vrrp[11028]: VRRP_Instance(VI_1) Sending/queueing gratuitous ARPs on eth0 for 192.168.24.188
Sep 14 03:08:31 linfan Keepalived_vrrp[11028]: Sending gratuitous ARP on eth0 for 192.168.24.188
Sep 14 03:08:31 linfan Keepalived_vrrp[11028]: Sending gratuitous ARP on eth0 for 192.168.24.188
Sep 14 03:08:31 linfan Keepalived_vrrp[11028]: Sending gratuitous ARP on eth0 for 192.168.24.188
Sep 14 03:08:31 linfan Keepalived_vrrp[11028]: Sending gratuitous ARP on eth0 for 192.168.24.188再看看master2機器，發現vip資源又被恢復後的master1搶過去了
[root@linfan ~]# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
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 00:0c:29:8f:c0:2c brd ff:ff:ff:ff:ff:ff
inet 192.168.24.130/24 brd 192.168.24.255 scope global eth0
valid_lft forever preferred_lft forever
inet6 fe80::20c:29ff:fe8f:c02c/64 scope link
valid_lft forever preferred_lft forever
[root@linfan ~]# tail -f /var/log/messages
Sep 14 03:08:25 linfan Keepalived_vrrp[6710]: VRRP_Instance(VI_1) Received advert with higher priority 101, ours 99
Sep 14 03:08:25 linfan Keepalived_vrrp[6710]: VRRP_Instance(VI_1) Entering BACKUP STATE
Sep 14 03:08:25 linfan Keepalived_vrrp[6710]: VRRP_Instance(VI_1) removing protocol VIPs.4）同樣，關閉master1機器的keepalived服務，vip資源會自動切換到master2機器上。當master1的keepalived服務恢復後，會將vip資源再次切回來。
[root@linfan ~]# /etc/init.d/keepalived stop
Stopping keepalived (via systemctl): [ OK ]
[root@linfan ~]# ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
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 00:0c:29:23:40:f6 brd ff:ff:ff:ff:ff:ff
inet 192.168.24.128/24 brd 192.168.24.255 scope global eth0
valid_lft forever preferred_lft forever
inet 192.168.24.146/24 brd 192.168.24.255 scope global secondary dynamic eth0
valid_lft 1351sec preferred_lft 1351sec
inet6 fe80::20c:29ff:fe23:40f6/64 scope link
valid_lft forever preferred_lft forever查看master2，發現vip切過來了
[root@linfan ~]# ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
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 00:0c:29:8f:c0:2c brd ff:ff:ff:ff:ff:ff
inet 192.168.24.130/24 brd 192.168.24.255 scope global eth0
valid_lft forever preferred_lft forever
inet 192.168.24.188/32 scope global eth0
valid_lft forever preferred_lft forever
inet6 fe80::20c:29ff:fe8f:c02c/64 scope link
valid_lft forever preferred_lft forever再次恢復master1的keepalived服務，發現vip資源很快又切回來了。
[root@linfan ~]# /etc/init.d/keepalived start
Starting keepalived (via systemctl): [ OK ]
[root@linfan ~]# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
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 00:0c:29:23:40:f6 brd ff:ff:ff:ff:ff:ff
inet 192.168.24.128/24 brd 192.168.24.255 scope global eth0
valid_lft forever preferred_lft forever
inet 192.168.24.188/32 scope global eth0
valid_lft forever preferred_lft forever
inet 192.168.24.146/24 brd 192.168.24.255 scope global secondary dynamic eth0
valid_lft 1190sec preferred_lft 1190sec
inet6 fe80::20c:29ff:fe23:40f6/64 scope link
valid_lft forever preferred_lft forever再此查看master2，發現vip資源被切走了
[root@linfan ~]# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
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 00:0c:29:8f:c0:2c brd ff:ff:ff:ff:ff:ff
inet 192.168.24.130/24 brd 192.168.24.255 scope global eth0
valid_lft forever preferred_lft forever
inet6 fe80::20c:29ff:fe8f:c02c/64 scope link
valid_lft forever preferred_lft forever以上在vip資源切換過程中，對於客戶端連接mysql（使用vip連接）來說幾乎是沒有任何影響的。
溫馨提示（Keepalived的搶占和非搶占模式）
keepalive是基於vrrp協議在linux主機上以守護進程方式，根據配置文件實現健康檢查。
VRRP是一種選擇協議，它可以把一個虛擬路由器的責任動態分配到局域網上的VRRP路由器中的一臺。
控制虛擬路由器IP地址的VRRP路由器稱為主路由器，它負責轉發數據包到這些虛擬IP地址。
一旦主路由器不可用，這種選擇過程就提供了動態的故障轉移機制，這就允許虛擬路由器的IP地址可以作為終端主機的默認第一跳路由器。
keepalive通過組播，單播等方式（自定義），實現keepalive主備推選。工作模式分為搶占和非搶占（通過參數nopreempt來控制）。
1）搶占模式：
主服務正常工作時，虛擬IP會在主上，備不提供服務，當主服務優先級低於備的時候，備會自動搶占虛擬IP，這時，主不提供服務，備提供服務。
也就是說，工作在搶占模式下，不分主備，只管優先級。
如上配置，不管keepalived.conf裏的state配置成master還是backup，只看誰的priority優先級高（一般而言，state為MASTER的優先級要高於BACKUP）。
priority優先級高的那一個在故障恢復後，會自動將VIP資源再次搶占回來！！
2）非搶占模式：
這種方式通過參數nopreempt（一般設置在advert_int的那一行下面）來控制。不管priority優先級，只要MASTER機器發生故障，VIP資源就會被切換到BACKUP上。
並且當MASTER機器恢復後，也不會去將VIP資源搶占回來，直至BACKUP機器發生故障時，才能自動切換回來。
千萬註意：
nopreempt這個參數只能用於state為backup的情況，所以在配置的時候要把master和backup的state都設置成backup，這樣才會實現keepalived的非搶占模式！
也就是說：
a）當state狀態一個為master，一個為backup的時候，加不加nopreempt這個參數都是一樣的效果。即都是根據priority優先級來決定誰搶占vip資源的，是搶占模式！
b）當state狀態都設置成backup，如果不配置nopreempt參數，那麽也是看priority優先級決定誰搶占vip資源，即也是搶占模式。
c）當state狀態都設置成backup，如果配置nopreempt參數，那麽就不會去考慮priority優先級了，是非搶占模式！即只有vip當前所在機器發生故障，另一臺機器才能接管vip。即使優先級高的那一臺機器恢復 後也不會主動搶回vip，只能等到對方發生故障，才會將vip切回來。
mysql狀態檢測腳本優化
上面的mysql監測腳本有點過於簡單且粗暴，即腳本一旦監測到Master的mysql服務關閉，就立刻把keepalived服務關閉，從而實現vip轉移！
下面對該腳本進行優化，優化後，當監測到Master的mysql服務關閉後，就會將vip切換到Backup上（但此時Master的keepalived服務不會被暴力kill）
當Master的mysql服務恢復後，就會再次將VIP資源切回來！
[root@linfan keepalived-1.3.5]# vim /opt/chk_mysql.sh
#!/bin/bash
MYSQL=/usr/local/mysql/bin/mysql
MYSQL_HOST=localhost
MYSQL_USER=mysql
MYSQL_PASSWORD=linfan123
CHECK_TIME=3
#mysql is working MYSQL_OK is 1 , mysql down MYSQL_OK is 0
MYSQL_OK=1
function check_mysql_helth (){
$MYSQL -h $MYSQL_HOST -u $MYSQL_USER -p${MYSQL_PASSWORD} -e "show status;" >/dev/null 2>&1
if [ $? = 0 ] ;then
MYSQL_OK=1
else
MYSQL_OK=0
fi
return $MYSQL_OK
}
while [ $CHECK_TIME -ne 0 ]
do
let "CHECK_TIME -= 1"
check_mysql_helth
if [ $MYSQL_OK = 1 ] ; then
CHECK_TIME=0
exit 0
fi
if [ $MYSQL_OK -eq 0 ] && [ $CHECK_TIME -eq 0 ]
then
pkill keepalived
exit 1
fi
sleep 1
doneMysql+Keepalived雙主熱備高可用操作步驟詳細解析