MySQL複製配置（多主一從）

複製多主一從

 

replicaion

原理

複製有三個步驟：（分爲三個線程 slave：io線程 sql線程　master：io線程）

一、master將改變記錄到二進制日誌(binary log)中（這些記錄叫作二進制日誌事件，binary log events）

二、slave將master的binary log events拷貝到它的中繼日誌(relay log)

三、slave讀取中繼日誌中的事件，將其重放到slave數據之上

日誌解釋

從庫先經過io線程讀取主庫的二進制文件（Master_Log_File）和位置（Read_Master_Log_Pos）而後緩存到本地（從庫服務器）的中繼文件（Relay_Log_File）中並記錄已經讀取到的位置（Relay_Log_Pos），再經過從庫的sql線程去讀取中繼文件（Relay_Log_File），這個sql線程執行會記錄已經執行到了哪一個文件（Relay_Master_Log_File）和哪一個位置（Exec_Master_Log_Pos）。

配置複製

一、在master建立複製帳號　　

GRANT REPLICATION SLAVE,REPLICATION CLIENT ON *.* TO repl@'192.168.0.%' IDENTIFIED BY 'PASSWD';

二、配置master和slave

master
    server-id = 1
    log-bin = mysql-bin
    expire-logs-days = 10  # 設置二進制日誌過時的天數
    max_binlog_size = 512M  # 二進制日誌滾動的閥值

slave
    server-id = 2
    expire-logs-days = 10
    max-relay-log-size = 512M
    relay-log = mysql-relay-bin
    relay_log_recovery = 1  # 修復中繼日誌
    replicate_wild_ignore_table = mysql.%  # 過濾哪些主庫不復制

三、通知slave鏈接到master並從master複製數據

CHANGE MASTER TO MASTER_HOST='master',MASTER_USER='repl',MASTER_PASSWORD='passwd',MASTER_LOG_FILE='mysql-bin.000001',MASTER_LOG_POS=0; 

四、啓動複製，查看狀態

slave
　　START SLAVE

show slave status\G

在輸出信息中查看I/O線程和SQL線程的狀態值（YES爲正常，NO爲錯誤）

　　Slave_IO_Running: Yes

　　Slave_SQL_Running: Yes

 

mysqld_multi

與安裝單實例同樣，只是要初始化多個數據目錄對應相應的實例

mkdir -p /storage/data/mysql{1,2,3}
chown -R mysql:mysql /storage/data/mysql{1,2,3}
scripts/mysql_install_db --user=mysql --datadir=/storage/data/mysql1
scripts/mysql_install_db --user=mysql --datadir=/storage/data/mysql2
scripts/mysql_install_db --user=mysql --datadir=/storage/data/mysql3

添加多實例管理用戶

GRANT SHUTDOWN ON *.* TO 'multi'@'localhost' IDENTIFIED BY 'multi'

mysqld_multi

Usage: mysqld_multi [OPTIONS] {start|stop|report} [GNR,GNR,GNR...]

my.cnf

[mysqld_multi]
mysqld = /storage/server/mysql/bin/mysqld_safe
mysqladmin = /storage/server/mysql/bin/mysqladmin
user = multi
password = multi
log = /storage/data/mysqld_multi.log

[mysqld1]
# 3306 mysql1
port            = 3306
socket          = /tmp/mysql3306.sock
basedir = /storage/server/mysql
datadir = /storage/data/mysql1
character-set-server=utf8
collation-server=utf8_unicode_ci
server-id = 2
expire-logs-days = 10
max-relay-log-size = 512M
relay-log = mysql1-relay-bin
relay_log_recovery = 1
replicate_wild_ignore_table=mysql.%

[mysqld2]
# 3307 mysql2
port            = 3307
socket          = /tmp/mysql3307.sock
basedir = /storage/server/mysql
datadir = /storage/data/mysql2
character-set-server=utf8
collation-server=utf8_unicode_ci
server-id = 2
expire-logs-days = 10
max-relay-log-size = 512M
relay-log = mysql2-relay-bin
relay_log_recovery = 1
replicate_wild_ignore_table=mysql.%

[mysqld3]
# 3308 mysql3
port            = 3308
socket          = /tmp/mysql3308.sock
basedir = /storage/server/mysql
datadir = /storage/data/mysql3
character-set-server=utf8
collation-server=utf8_unicode_ci
server-id = 2
expire-logs-days = 10
max-relay-log-size = 512M
relay-log = mysql3-relay-bin
relay_log_recovery = 1
replicate_wild_ignore_table=mysql.%

mysql主從常見錯誤

error 1062

錯誤緣由：主鍵衝突 出現這種狀況就是從庫出現插入操做 主庫又從新來了一遍 iothread沒問題 sqlthread出錯

解決方案：從庫

mysql> stop slave;
mysql> set global sql_slave_skip_counter=1;
mysql> start slave;