准備工作:
- 完成keepalived的安裝
- 完成docker的安裝
- docker鏡像里面自行安裝
iproute2
,vim
,iputils-ping
(可選)等工具,便於測試
apt-get install iproute2 apt-get install vim apt-get install iputils-ping
主數據庫master
1. 使用docker安裝mysql
mkdir -p ~/compose/mysql-master cd ~/compose/mysql-master cat docker-compose.yml version: '2' services: mysql-master: image: mysql:5 restart: always container_name: mysql-master ports: - 3306:3306 volumes: - ./conf.d:/etc/mysql/conf.d - /data/docker/mysql-master/data:/var/lib/mysql environment: - MYSQL_ROOT_PASSWORD=123456 networks: default: external: name: service
假如沒有把3306端口映射到宿主機,在宿主機上可通過docker-ip:3306來訪問。
2. mysql的配置
cat conf.d/lowercase.cnf [mysqld] lower_case_table_names = 1 default-time-zone = '+08:00' character-set-server = utf8 event_scheduler = on log-bin = mysql-bin server-id = 1
參數說明:
lower_case_table_names
設置不區分大小寫default-time-zone
設置時區為東八區character-set-server
修改字符集為utf8log-bin
開啟二進制日志server-id
設置server-id
master開啟二進制日志后默認記錄所有庫所有表的操作,可以通過配置來指定只記錄指定的數據庫甚至指定的表的操作,具體在mysql配置文件的[mysqld]可添加修改如下選項:
# 不同步哪些數據庫
binlog-ignore-db = mysql binlog-ignore-db = test binlog-ignore-db = information_schema
# 只同步哪些數據庫,除此之外,其他不同步
binlog-do-db = mydatabase
3. 啟動服務
docker-compose pull && docker-compose up -d
4. 在宿主機連接mysql
說明: 由於我是使用虛擬機安裝的字符版Ubuntu系統,所以使用MyCli作為mysql命令行工具來連接mysql。
# 查看master主機的ip地址為192.168.11.188,使用MyCli連接mysql mycli -h 192.168.11.188 -u root -p 123456 # 給root用戶分配遠程訪問權限: grant all on *.* to root@'%' identified by "123456"; flush privileges; # 查看master狀態 mysql root@192.168.11.188:(none)> SHOW MASTER STATUS; +------------------+----------+--------------+------------------+-------------------+ | File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set | +------------------+----------+--------------+------------------+-------------------+ | mysql-bin.000003 | 586 | | | | +------------------+----------+--------------+------------------+-------------------+ 1 row in set Time: 0.004s
需要記錄主數據庫的二進制文件名(mysql-bin.000003)和位置586。
從數據庫slave
1. docker-compose.yml
只需要從主數據庫的配置名稱由mysql-master
改為mysql-slave
即可。
2. mysql配置
cat conf.d/lowercase.cnf [mysqld] lower_case_table_names = 1 default-time-zone = '+08:00' character-set-server = utf8 event_scheduler = on server-id= 2
需添加server-id
並且與主數據庫中不一致
3. 啟動服務
docker-compose pull && docker-compose up -d
4. 在宿主機連接mysql
# 查看slave主機的ip地址為192.168.11.186,使用MyCli連接mysql mycli -h 192.168.11.186 -u root -p 123456 # 給root用戶分配遠程訪問權限,略 # 執行同步SQL語句,參照MASTER配置: CHANGE MASTER TO MASTER_HOST='192.168.11.188',MASTER_USER='root',MASTER_PASSWORD='123456',MASTER_LOG_FILE='mysql-bin.000003',MASTER_LOG_POS=586; # 啟動slave同步進程 start slave; # 查看slave狀態: show slave status\G;
其中下面兩項為YES則表示成功:
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
測試主從復制
在MASTER中新建數據庫和表,發現數據在SLAVE中已經實時同步過來
Keepalived監控mysql服務
1. master主機上的配置
cat /etc/keepalived/keepalived.conf 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" #這里通過腳本監測 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 ens33 #指定虛擬ip的網卡接口,不一定是eth0根據ifconfig確定 virtual_router_id 51 #路由器標識,MASTER和BACKUP必須是一致的 priority 100 #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故障恢復后,就可以將VIP資源再次搶回來 advert_int 1 authentication { auth_type PASS auth_pass 123456 } virtual_ipaddress { 192.168.11.25 } track_script { chk_mysql_port } }
需要配置的地方有:script
,state
,interface
,virtual_router_id
,priority
,virtual_ipaddress
等
2. slave主機上的配置
cat /etc/keepalived/keepalived.conf 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 ens33 virtual_router_id 51 priority 99 advert_int 1 authentication { auth_type PASS auth_pass 123456 } virtual_ipaddress { 192.168.11.25 } track_script { chk_mysql_port } }
只需要設置state
為BACKUP
, priority
比MASTER低即可。
3. 監測監本的配置
cat /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 else echo "running..." >> /opt/keepalived-running-info.log sleep 5000 fi
Keepalived監測Mysql測試
先要保證兩台服務器的mysql服務正常啟動哦~
1. 啟動Keepalived
# 在master和slave上執行 sudo /etc/init.d/keepalived start # 查看腳本是否正常執行 tail -f /opt/keepalived-running-info.log # 查看master的ip,發現虛擬ip綁定成功 ip addr 2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000 link/ether 00:0c:29:64:35:17 brd ff:ff:ff:ff:ff:ff inet 192.168.11.188/24 brd 192.168.11.255 scope global ens33 valid_lft forever preferred_lft forever inet 192.168.11.25/32 scope global ens33 valid_lft forever preferred_lft forever inet6 fe80::20c:29ff:fe64:3517/64 scope link valid_lft forever preferred_lft forever
2. 高可用測試
在任意一台主機執行以下命令測試:
mycli -h 192.168.11.25 -u root -p 123456 #ok mycli -h 192.168.11.188 -u root -p 123456 #ok mycli -h 192.168.11.186 -u root -p 123456 #ok
再次查看master主機的ip,發現虛擬ip不見了:
ip addr 2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000 link/ether 00:0c:29:64:35:17 brd ff:ff:ff:ff:ff:ff inet 192.168.11.188/24 brd 192.168.11.255 scope global ens33 valid_lft forever preferred_lft forever inet6 fe80::20c:29ff:fe64:3517/64 scope link valid_lft forever preferred_lft forever
此時查看slave主機的ip定, 發現ip漂移情況,虛擬ip自動綁定到到了slave主機上:
ip addr 2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000 link/ether 00:0c:29:f0:00:ad brd ff:ff:ff:ff:ff:ff inet 192.168.11.186/24 brd 192.168.11.255 scope global ens33 valid_lft forever preferred_lft forever inet 192.168.11.25/32 scope global ens33 valid_lft forever preferred_lft forever inet6 fe80::20c:29ff:fef0:ad/64 scope link valid_lft forever preferred_lft forever
此時查看slave主機情況,Slave_IO_Running
變成了Connecting
:
mycli -h 192.168.11.186 -u root -p 123456 show slave status\G;
Slave_IO_Running | Connecting
Slave_SQL_Running | Yes
繼續測試
現在把master重新啟動
mycli -h 192.168.11.188 -u root -p 123456 #ok show master status; +------------------+----------+--------------+-------------------------------+-------------------+ | File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set | +------------------+----------+--------------+-------------------------------+-------------------+ | mysql-bin.000009 | 154 | | mysql,test,information_schema | | +------------------+----------+--------------+-------------------------------+-------------------+ 1 row in set Time: 0.004s
會發現信息發生了改變,再次查看slave的狀態恢復正常:
Slave_IO_Running | Yes
Slave_SQL_Running | Yes
繼續查看master主機發現未綁定vip,vip依然存在於slave所屬主機上面。
那么現在把slave停掉試試看:
docker stop mysql-slave mycli -h 192.168.11.186 -u root -p 123456 #error mycli -h 192.168.11.25 -u root -p 123456 # error mycli -h 192.168.11.188 -u root -p 123456 # ok
出現只有master主機的mysql服務能訪問的情況,是因為上面測試把兩個mysql服務停止,腳本監測不到3306端口執行了/etc/init.d/keepalived stop
,所以需要重新啟動keepalived :
# master主機 sudo /etc/init.d/keepalived start # slave主機 docker start mysql-slave sudo /etc/init.d/keepalived start
這個時候發現vip又重新綁定到master上面,OK,一切正常。
總結:
寫的可能有些啰嗦,但是每一步的操作和測試又是必要的,只為記錄自己的一次學習心得。