請耐心讀完整篇文章，過程中出現的錯誤點在文章結尾都有總結和解決辦法。
服務器架構
安裝MySQL
創建mysql用戶
groupadd mysql
useradd -r -g mysql -s /bin/false mysql
安裝MySQL
yum install -y libaio
cd /usr/local/src/
wget http://mirrors.sohu.com/mysql/MySQL-5.7/mysql-5.7.17-linux-glibc2.5-x86_64.tar.gz
tar -zxf mysql-5.7.17-linux-glibc2.5-x86_64.tar.gz
cp -rf mysql-5.7.17-linux-glibc2.5-x86_64 /data/app/mysql-3306
cp -rf mysql-5.7.17-linux-glibc2.5-x86_64 /data/app/mysql-3307
chown -R mysql:mysql /data/app/mysql-3306
chown -R mysql:mysql /data/app/mysql-3307
/data/app/mysql-3306/bin/mysqld --initialize-insecure --user=mysql --basedir=/data/app/mysql-3306 --datadir=/data/app/mysql-3306/data
/data/app/mysql-3307/bin/mysqld --initialize-insecure --user=mysql --basedir=/data/app/mysql-3307 --datadir=/data/app/mysql-3307/data
修改my.cnf
需要修改的參數：
· server-id：保證每個配置文件唯一
· 兩臺master的自增長ID必須不同
linux-node2
master
cat > /data/app/mysql-3306/my.cnf<<EOF
[client]
port = 3306
socket = /data/app/mysql-3306/mysql.sock
[mysqld]
port = 3306
user = mysql
server-id = 1
bind-address = 0.0.0.0
basedir = /data/app/mysql-3306
datadir = /data/app/mysql-3306/data
socket = /data/app/mysql-3306/mysql.sock
pid-file = /data/app/mysql-3306/mysql.pid
log-error = /data/app/mysql-3306/mysqld.log
skip-name-resolve
log_bin = mysql-bin
log-slave-updates
auto-increment-increment = 2
auto-increment-offset = 1
sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES
EOF
chown mysql.mysql /data/app/mysql-3306/my.cnf
slave
cat > /data/app/mysql-3307/my.cnf<<EOF
[client]
port = 3307
socket = /data/app/mysql-3307/mysql.sock
[mysqld]
port = 3307
user = mysql
server-id = 11
bind-address = 0.0.0.0
basedir = /data/app/mysql-3307
datadir = /data/app/mysql-3307/data
socket = /data/app/mysql-3307/mysql.sock
pid-file = /data/app/mysql-3307/mysql.pid
log-error = /data/app/mysql-3307/mysqld.log
skip-name-resolve
log_bin = mysql-bin
sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES
EOF
chown mysql.mysql /data/app/mysql-3307/my.cnf
linux-node3
master
cat > /data/app/mysql-3306/my.cnf<<EOF
[client]
port = 3306
socket = /data/app/mysql-3306/mysql.sock
[mysqld]
port = 3306
user = mysql
server-id = 2
bind-address = 0.0.0.0
basedir = /data/app/mysql-3306
datadir = /data/app/mysql-3306/data
socket = /data/app/mysql-3306/mysql.sock
pid-file = /data/app/mysql-3306/mysql.pid
log-error = /data/app/mysql-3306/mysqld.log
skip-name-resolve
log_bin = mysql-bin
log-slave-updates
auto-increment-increment = 2
auto-increment-offset = 2
sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES
EOF
chown mysql.mysql /data/app/mysql-3306/my.cnf
slave
cat > /data/app/mysql-3307/my.cnf<<EOF
[client]
port = 3307
socket = /data/app/mysql-3307/mysql.sock
[mysqld]
port = 3307
user = mysql
server-id = 22
bind-address = 0.0.0.0
basedir = /data/app/mysql-3307
datadir = /data/app/mysql-3307/data
socket = /data/app/mysql-3307/mysql.sock
pid-file = /data/app/mysql-3307/mysql.pid
log-error = /data/app/mysql-3307/mysqld.log
skip-name-resolve
log_bin = mysql-bin
sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES
EOF
chown mysql.mysql /data/app/mysql-3307/my.cnf
啓動MySQL
啓動服務
linux-node2和linux-node3都執行如下命令
touch /data/app/mysql-3306/mysqld.log && chown mysql.mysql /data/app/mysql-3306/mysqld.log
sed -i 's#/usr/local/mysql#/data/app/mysql-3306#g' /data/app/mysql-3306/bin/mysqld_safe
/data/app/mysql-3306/bin/mysqld_safe --defaults-file=/data/app/mysql-3306/my.cnf --basedir=/data/app/mysql-3306 --datadir=/data/app/mysql-3306/data --user=mysql &
touch /data/app/mysql-3307/mysqld.log && chown mysql.mysql /data/app/mysql-3307/mysqld.log
sed -i 's#/usr/local/mysql#/data/app/mysql-3307#g' /data/app/mysql-3307/bin/mysqld_safe
/data/app/mysql-3307/bin/mysqld_safe --defaults-file=/data/app/mysql-3307/my.cnf --basedir=/data/app/mysql-3307 --datadir=/data/app/mysql-3307/data --user=mysql &
檢查端口
ss -lntup |egrep '3306|3307'
tcp LISTEN 0 80 *:3306 *:* users:(("mysqld",19973,22))
tcp LISTEN 0 80 *:3307 *:* users:(("mysqld",20537,22))
配置雙主
配置主從
linux-node2
master
cd /data/app/mysql-3306/
./bin/mysql -uroot -p -S mysql.sock -P 3306
mysql> CREATE USER 'repl'@'192.%' IDENTIFIED BY 'mysql';
Query OK, 0 rows affected (0.05 sec)
mysql> GRANT REPLICATION SLAVE ON *.* TO 'repl'@'192.%';
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.000001 | 613 | | | |
+------------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)
slave
cd /data/app/mysql-3307/
./bin/mysql -uroot -p -S mysql.sock -P 3307
mysql> CHANGE MASTER TO MASTER_HOST='192.168.56.12',
-> MASTER_PORT=3306,
-> MASTER_USER='repl',
-> MASTER_PASSWORD='mysql',
-> MASTER_LOG_FILE='mysql-bin.000001',
-> MASTER_LOG_POS=613;
Query OK, 0 rows affected, 2 warnings (0.04 sec)
mysql> start slave;
Query OK, 0 rows affected (0.02 sec)
mysql> show slave status\G
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 192.168.56.12
Master_User: repl
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin.000001
Read_Master_Log_Pos: 613
Relay_Log_File: linux-node2-relay-bin.000002
Relay_Log_Pos: 320
Relay_Master_Log_File: mysql-bin.000001
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
linux-node3
master
cd /data/app/mysql-3306/
./bin/mysql -uroot -p -S mysql.sock -P 3306
mysql> CREATE USER 'repl'@'192.%' IDENTIFIED BY 'mysql';
Query OK, 0 rows affected (0.05 sec)
mysql> GRANT REPLICATION SLAVE ON *.* TO 'repl'@'192.%';
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.000001 | 613 | | | |
+------------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)
slave
cd /data/app/mysql-3307/
./bin/mysql -uroot -p -S mysql.sock -P 3307
mysql>
CHANGE MASTER TO MASTER_HOST='192.168.56.13',
MASTER_PORT=3306,
MASTER_USER='repl',
MASTER_PASSWORD='mysql',
MASTER_LOG_FILE='mysql-bin.000001',
MASTER_LOG_POS=613;
Query OK, 0 rows affected, 2 warnings (0.04 sec)
mysql> start slave;
Query OK, 0 rows affected (0.02 sec)
mysql> show slave status\G
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 192.168.56.13
Master_User: repl
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin.000001
Read_Master_Log_Pos: 613
Relay_Log_File: linux-node2-relay-bin.000002
Relay_Log_Pos: 320
Relay_Master_Log_File: mysql-bin.000001
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
配置雙主
master的binlog位置
linux-node2 master端
d /data/app/mysql-3306/
./bin/mysql -uroot -p -S mysql.sock -P 3306
mysql> show master status;
+------------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+-------------------+
| mysql-bin.000001 | 613 | | | |
+------------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)
linux-node3 master端
cd /data/app/mysql-3306/
./bin/mysql -uroot -p -S mysql.sock -P 3306
mysql> show master status;
+------------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+-------------------+
| mysql-bin.000001 | 613 | | | |
+------------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)
linux-node2 master配置跟linux-node3 master同步
mysql> CHANGE MASTER TO MASTER_HOST='192.168.56.13',
MASTER_PORT=3306,
MASTER_USER='repl',
MASTER_PASSWORD='mysql',
MASTER_LOG_FILE='mysql-bin.000001',
MASTER_LOG_POS=613;
mysql> start slave;
Query OK, 0 rows affected (0.03 sec)
mysql> show slave status\G
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 192.168.56.13
Master_User: repl
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin.000001
Read_Master_Log_Pos: 613
Relay_Log_File: linux-node2-relay-bin.000002
Relay_Log_Pos: 320
Relay_Master_Log_File: mysql-bin.000001
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
linux-node3 master配置跟linux-node2 master同步
mysql> CHANGE MASTER TO MASTER_HOST='192.168.56.12',
MASTER_PORT=3306,
MASTER_USER='repl',
MASTER_PASSWORD='mysql',
MASTER_LOG_FILE='mysql-bin.000001',
MASTER_LOG_POS=613;
mysql> start slave;
Query OK, 0 rows affected (0.00 sec)
mysql>
mysql> show slave status\G
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 192.168.56.12
Master_User: repl
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin.000001
Read_Master_Log_Pos: 613
Relay_Log_File: linux-node3-relay-bin.000002
Relay_Log_Pos: 320
Relay_Master_Log_File: mysql-bin.000001
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
驗證
從linux-node2上驗證
在linux-node2 master上創建數據
mysql> create database test;
Query OK, 1 row affected (0.01 sec)
mysql> use test;
Database changed
mysql> create table temp(id int,name varchar(64));
Query OK, 0 rows affected (0.11 sec)
mysql> insert into temp values(1,'aaa');
Query OK, 1 row affected (0.28 sec)
mysql> CREATE TABLE temp2(id INT PRIMARY KEY NOT NULL AUTO_INCREMENT ,nname VARCHAR(64));
Query OK, 0 rows affected (0.01 sec)
mysql> insert into temp2(nname) values('bbb');
Query OK, 1 row affected (0.01 sec)
mysql> select * from test.temp;
+------+------+
| id | name |
+------+------+
| 1 | aaa |
+------+------+
1 row in set (0.01 sec)
在linux-node2 slave上查看數據
mysql> select * from test.temp;
+------+------+
| id | name |
+------+------+
| 1 | aaa |
+------+------+
1 row in set (0.00 sec)
在linux-node3 master上查看數據
mysql> select * from test.temp;
+------+------+
| id | name |
+------+------+
| 1 | aaa |
+------+------+
1 row in set (0.00 sec)
在linux-node3 slave上查看數據
mysql> select * from test.temp;
+------+------+
| id | name |
+------+------+
| 1 | aaa |
+------+------+
1 row in set (0.00 sec)
從linux-node3上驗證
在linux-node3 master上創建數據
mysql> use test;
mysql> insert into temp2(nname) values('ddd');
Query OK, 1 row affected (0.02 sec)
mysql> insert into temp2(nname) values('fff');
Query OK, 1 row affected (0.00 sec)
mysql> select * from test.temp2;
+----+-------+
| id | nname |
+----+-------+
| 1 | bbb |
| 2 | ddd |
| 4 | fff |
+----+-------+
在linux-node3 slave上查看數據
mysql> select * from test.temp2;
+----+-------+
| id | nname |
+----+-------+
| 1 | bbb |
| 2 | ddd |
| 4 | fff |
+----+-------+
3 rows in set (0.00 sec)
在linux-node2 master上查看數據
mysql> select * from test.temp2;
+----+-------+
| id | nname |
+----+-------+
| 1 | bbb |
| 2 | ddd |
| 4 | fff |
+----+-------+
3 rows in set (0.00 sec)
在linux-node2 slave上查看數據
mysql> select * from test.temp2;
+----+-------+
| id | nname |
+----+-------+
| 1 | bbb |
| 2 | ddd |
| 4 | fff |
+----+-------+
3 rows in set (0.00 sec)
結論
· 在任意一個master端更新數據，其他任意端都可以更新數據
· 兩臺服務器配置了間隔自增長，數據不同衝突
linux-node1上安裝mycat
安裝mycat
cd /usr/local/src
wget http://dl.mycat.io/1.6-RELEASE/Mycat-server-1.6-RELEASE-20161028204710-linux.tar.gz
tar -zxf Mycat-server-1.6-RELEASE-20161028204710-linux.tar.gz
mv mycat /data/app/mycat-1.6
ln -s /data/app/mycat-1.6 /data/app/mycat
修改schema.xml
· balance="1"
全部的readHost與stand by writeHost參與select語句的負載均衡
· writeType="0"
所有寫操作發送到配置的第一個writeHost，第一個掛了切到還生存的第二個 writeHost，重新啓動後以切換後的爲準，切換記錄在配置文件中:dnindex.properties
· switchType="1"
默認值爲1，自動切換
cd /data/app/mycat
cp conf/schema.xml conf/schema.xml.bak
cat > conf/schema.xml <<EOF
<?xml version="1.0"?>
<!DOCTYPE mycat:schema SYSTEM "schema.dtd">
<mycat:schema xmlns:mycat="http://io.mycat/">
<schema name="TESTDB" checkSQLschema="true" sqlMaxLimit="100" dataNode="dn1"></schema>
<dataNode name="dn1" dataHost="node1" database="test" />
<dataHost name="node1" maxCon="10" minCon="5" balance="1" writeType="0" dbType="mysql" dbDriver="native" switchType="1">
<heartbeat>select user()</heartbeat>
<writeHost host="master1" url="192.168.56.12:3306" user="root" password="mysql">
<readHost host="slave2" url="192.168.56.13:3307" user="root" password="mysql" />
</writeHost>
<writeHost host="master2" url="192.168.56.13:3306" user="root" password="mysql">
<readHost host="slave2" url="192.168.56.13:3307" user="root" password="mysql" />
</writeHost>
</dataHost>
</mycat:schema>
EOF
啓動mycat
./bin/mycat start
ss -lntup |egrep '(8066|9066)'
tcp LISTEN 0 100 :::8066 :::* users:(("java",16546,79))
tcp LISTEN 0 100 :::9066 :::* users:(("java",16546,75))
驗證mycat服務是否正常
在linux-node2-master端配置mycat連接賬號
mysql> GRANT ALL PRIVILEGES ON *.* TO root@'192.%' IDENTIFIED BY 'mysql';
Query OK, 0 rows affected, 1 warning (0.07 sec
在mycat服務器上安裝mysql服務，但是不啓動
步驟省略，詳細內容可以參考上面的MySQL安裝
使用mysql的客戶端連接mycat
cd /data/app/mysql/
./bin/mysql -uroot -p -P 8066 -h 192.168.56.11 ##連接mycat，初始密碼123456
mysql> show databases;
+----------+
| DATABASE |
+----------+
| TESTDB |
+----------+
1 row in set (0.00 sec)
mysql> use TESTDB;
mysql> insert into temp2(nname) values('eee');
Query OK, 1 row affected (0.09 sec)
mysql> insert into temp2(nname) values('ggg');
Query OK, 1 row affected (0.01 sec)
linux-node3 slave端查看數據是否同步
mysql> select * from test.temp2;
+----+-------+
| id | nname |
+----+-------+
| 1 | bbb |
| 2 | ddd |
| 4 | fff |
| 5 | eee |
| 7 | ggg |
+----+-------+
5 rows in set (0.00 sec)
結果發現數據寫入到了linux-node2 slave端
測試
服務自動遷移
關閉linux-node2 master的MySQL服務
mysql> shutdown;
Query OK, 0 rows affected (0.01 sec)
shell > ss -lntup |grep 3306
mycat端插入新的數據查看數據是否同步
mysql> insert into temp2(nname) values('mmmm');
Query OK, 1 row affected (0.07 sec)
mysql> insert into temp2(nname) values('nnnn');
Query OK, 1 row affected (0.01 sec)
linux-node3 slave端查看數據是否同步
mysql> select * from test.temp2;
+----+-------+
| id | nname |
+----+-------+
| 1 | bbb |
| 2 | ddd |
| 4 | fff |
| 5 | eee |
| 7 | ggg |
| 8 | mmmm |
| 10 | nnnn |
+----+-------+
7 rows in set (0.00 sec)
linux-node2 slave端查看數據是否同步
mysql> select * from test.temp2;
+----+-------+
| id | nname |
+----+-------+
| 1 | bbb |
| 2 | ddd |
| 4 | fff |
| 5 | eee |
| 7 | ggg |
+----+-------+
5 rows in set (0.00 sec)
發現因爲linux-node2的master端已經掛了，數據不能同步了
數據訪問是否正常
登錄到mycat服務器上執行如下命令：
mysql> select * from temp2;
+----+-------+
| id | nname |
+----+-------+
| 1 | bbb |
| 2 | ddd |
| 4 | fff |
| 5 | eee |
| 7 | ggg |
| 8 | mmmm |
| 10 | nnnn |
+----+-------+
7 rows in set (0.00 sec)
執行多次發現結果一樣，說明在一臺master端掛掉的情況下，其連接的slave端也被剔除，因此數據完整性可以保證
故障彙總
第一次配置的時候maser端沒有配置log-slave-updates，導致node3-slave上沒有node2-master端的數據。
解釋：
從庫開啓log-bin參數，如果直接往從庫寫數據，是可以記錄log-bin日誌的，但是從庫通過I0線程讀取主庫二進制日誌文件，然後通過SQL線程寫入的數據，是不會記錄binlog日誌的。也就是說從庫從主庫上覆制的數據，是不寫入從庫的binlog日誌的。所以從庫做爲其他從庫的主庫時需要在配置文件中添加log-slave-updates參數。
解決辦法：
[mysqld]
log-slave-updates