【减轻复制压力】复制过滤器，指定需要复制的白名单，或者需要忽略的黑名单
[root@localhost ~]# cd /etc/[root@localhost etc]# cp my.cnf{,.master}[root@localhost etc]# ll my.cnf*-rw-r--r--. 1 root root 4686 10月 13 04:43 my.cnf-rw-r--r--. 1 root root 4686 10月 14 20:00 my.cnf.master vim my.cnf:
[mysqld]
master:
binlog_do_db=
binlog_ignore_db=
slave:
replicate_do_db=
replicate_ignore_db=
replicate_do_table= db_name.table_name
replicate_ignore_table=
replicate_wild_do_table=
replicate_wild_ignore_table=
6、双主模型
1）、在两台服务器上各自建立一个具有复制权限的用户；
2）、修改配置文件：
【确保双方服务器数据一致，才能这么做！，本演示是在以前的一主一从的拓扑演变而来】
#【主服务器A上】
[root@localhost etc]# cp /etc/my.cnf /etc/my.cnf.master[root@localhost etc]# vim /etc/my.cnf +61[mysqld]datadir= /mydata/dataserver-id = 1log-bin=/mydata/binlogs/master-binrelay_log = /mydata/relaylogs/relay-binauto-increment-offset = 1 #注意起始值顺序不要写反auto-increment-increment = 2 #注意步长顺序需要写反skip_slave_start 跳过自动启动slave，因为自动的容易出错[root@localhost etc]# mkdir -pv /mydata/relaylogs/mkdir: 已创建目录 "/mydata/relaylogs/"[root@localhost etc]# chown -R mysql:mysql /mydata/relaylogs/[root@localhost etc]# service mysqld restart[root@localhost ~]# mysql -pEnter password:mysql> show master status;保留此时的状态，不要再操作这个mysql服务器+-------------------+----------+| File | Position |+-------------------+----------+| master-bin.000007 | 107 |+-------------------+----------+1 row in set (0.00 sec)
# 【主服务器B上】
[root@localhost ~]# cp /etc/my.cnf /etc/my.cnf.slave[mysqld]server-id = 11log-bin=/mydata/binlogs/master-logbinlog_format=mixed #启用# read-only = ON # 注释原来的只读auto-increment-offset = 2 #注意起始值顺序不要写反auto-increment-increment = 2 #注意步长顺序需要写反skip_slave_start #跳过自动启动slave，因为自动的容易出错[root@localhost ~]# mkdir -pv /mydata/binlogs/mkdir: 已创建目录 "/mydata/binlogs/"[root@localhost ~]# chown -R mysql:mysql /mydata/binlogs/[root@localhost etc]# service mysqld restart[root@localhost ~]# mysql -pEnter password: #为对方创建一个具有所有权限的用户mysql> GRANT REPLICATION SLAVE, REPLICATION CLIENT ON *.* TO 'repluser'@'192.168.%.%' IDENTIFIED BY 'replpass';Query OK, 0 rows affected (0.00 sec)mysql> FLUSH PRIVILEGES;Query OK, 0 rows affected (0.01 sec) #检查SLAVE的状态mysql> SHOW SLAVE STATUS\G*************************** 1. row *************************** Slave_IO_State: Master_Host: 192.168.81.132 Master_User: repluser Master_Port: 3306 Connect_Retry: 60 Master_Log_File: master-bin.000006 Read_Master_Log_Pos: 107 Relay_Log_File: relay-bin.000007 Relay_Log_Pos: 254Relay_Master_Log_File: master-bin.000006 Slave_IO_Running: No 没启动 Slave_SQL_Running: No 没启动用对方服务器192.168.81.132的repluser账户，指向对方服务器的日志文件 mysql> CHANGE MASTER TO MASTER_HOST='192.168.81.132', MASTER_USER='repluser', MASTER_PASSWORD='replpass',MASTER_LOG_FILE = 'master-bin.000007',MASTER_LOG_POS = 107;Query OK, 0 rows affected (0.05 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: 192.168.81.132 Master_User: repluser Master_Port: 3306 Connect_Retry: 60 Master_Log_File: master-bin.000007 Read_Master_Log_Pos: 107 Relay_Log_File: relay-bin.000002 Relay_Log_Pos: 254Relay_Master_Log_File: master-bin.000007 Slave_IO_Running: Yes Slave_SQL_Running: Yes 查看主服务器B的状态【注意，不要再把服务器B当slave的思维】mysql> show master status;+-------------------+----------+| File | Position |+-------------------+----------+| master-log.000002 | 370 |+-------------------+----------+1 row in set (0.00 sec)
【在服务器A操作，把主指向服务器B】注意你的iptables
注意：用对方服务器192.168.81.133的repluser账户，指向对方服务器的日志文件mysql> CHANGE MASTER TO MASTER_HOST='192.168.81.133', MASTER_USER='repluser', MASTER_PASSWORD='replpass',MASTER_LOG_FILE = 'master-log.000002',MASTER_LOG_POS = 370;Query OK, 0 rows affected (0.03 sec)mysql> show slave status\G*************************** 1. row *************************** Slave_IO_State: Master_Host: 192.168.81.133 Master_User: repluser Master_Port: 3306 Connect_Retry: 60 Master_Log_File: master-master-log.000002 Read_Master_Log_Pos: 370 Relay_Log_File: relay-bin.000001 Relay_Log_Pos: 4Relay_Master_Log_File: master-master-log.000002 Slave_IO_Running: No Slave_SQL_Running: No 启动互为主从mysql> start slave ;Query OK, 0 rows affected (0.01 sec)mysql> show slave status\G*************************** 1. row *************************** Slave_IO_State: Waiting for master to send event Master_Host: 192.168.81.133 Master_User: repluser Master_Port: 3306 Connect_Retry: 60 Master_Log_File: master-log.000002 Read_Master_Log_Pos: 370 Relay_Log_File: relay-bin.000002 Relay_Log_Pos: 254Relay_Master_Log_File: master-log.000002 Slave_IO_Running: Yes Slave_SQL_Running: Yes 【测试】在服务器A上创建一个数据库，并使用这个库创建自动增长的表mysql> create database newdb;Query OK, 1 row affected (0.00 sec)
【在服务器B上】查看是否存在
mysql> show databases;+--------------------+| Database |+--------------------+| information_schema || haha || hellodb || mysql || newdb || performance_schema || test |+--------------------+7 rows in set (0.00 sec)mysql> use newdb;Database changedmysql> create table t1(id int unsigned not null primary key auto_increment,name char(20));Query OK, 0 rows affected (0.05 sec)mysql> insert into t1 (name) values ('tom'),('jerry');Query OK, 2 rows affected (0.01 sec)Records: 2 Duplicates: 0 Warnings: 0mysql> select * from t1;+----+-------+| id | name |+----+-------+| 2 | tom || 4 | jerry |+----+-------+2 rows in set (0.00 sec) 【测试】在服务器A器上操作
mysql> use newdb;Database changedmysql> insert into t1 (name) values ('user1'),('user2');Query OK, 2 rows affected (0.02 sec)Records: 2 Duplicates: 0 Warnings: 0mysql> select * from t1;+----+-------+| id | name |+----+-------+| 2 | tom || 4 | jerry || 5 | user1 || 7 | user2 |+----+-------+4 rows in set (0.00 sec)mysql> select last_insert_id();+------------------+| last_insert_id() |+------------------+| 5 |+------------------+1 row in set (0.00 sec)【注意】如果再次修改过mysqld配置文件。要手动启动slave[root@localhost etc]# service mysqld restart[root@localhost ~]# mysql -pEnter password: mysql> start slave;Query OK, 0 rows affected (0.05 sec)mysql> create table t2 like t1; | 或者mysql> truncate t2;清空自动增长Query OK, 0 rows affected (0.02 sec)mysql> select * from t2;+----+-------+| id | name |+----+-------+| 1 | user1 || 3 | user2 |+----+-------+2 rows in set (0.01 sec) 【最简单的双主模型 就是这样！】
推荐：
多主，且高可用的解决方案：
MMM：Multi Master MySQL
MHA：MySQL HA
基于ssl的复制【大概的讲一下】
mysql> show variables like "%ssl%";+---------------+-------+| Variable_name | Value |+---------------+-------+| have_openssl | NO || have_ssl | NO || ssl_ca | || ssl_capath | || ssl_cert | || ssl_cipher | || ssl_key | |+---------------+-------+7 rows in set (0.00 sec)需要编译安装好后，才能enable ssl的功能client发送证书给serverserver验证客户端使用方法mysql> help change master toSyntax:CHANGE MASTER TO option [, option] ...option: MASTER_BIND = 'interface_name' | MASTER_HOST = 'host_name' | MASTER_USER = 'user_name' | MASTER_PASSWORD = 'password' | MASTER_PORT = port_num | MASTER_CONNECT_RETRY = interval | MASTER_HEARTBEAT_PERIOD = interval | MASTER_LOG_FILE = 'master_log_name' | MASTER_LOG_POS = master_log_pos | RELAY_LOG_FILE = 'relay_log_name' | RELAY_LOG_POS = relay_log_pos | MASTER_SSL = {0|1} | MASTER_SSL_CA = 'ca_file_name' | MASTER_SSL_CAPATH = 'ca_directory_name' | MASTER_SSL_CERT = 'cert_file_name' | MASTER_SSL_KEY = 'key_file_name' | MASTER_SSL_CIPHER = 'cipher_list' | MASTER_SSL_VERIFY_SERVER_CERT = {0|1} | IGNORE_SERVER_IDS = (server_id_list)server_id_list: [server_id [, server_id] ... ] 复制相关的文件：
master.info: 文本文件，保存从服务器连接至主服务时所需要的信息，每行一个值；
有了这些才会自动启动change master to,删除了就不会自动连接了
relay-log.info: 文本文件，保存了复制位置：包括二进制日志和中继日志的文件及位置；
[root@localhost data]# cat /mydata/data/master.info 18master-log.000003107192.168.81.133repluserreplpass330660001800.00000000[root@localhost data]# cat /mydata/data/relay-log.info /mydata/relaylogs/relay-bin.000007254master-log.000003107370
[Action !]
这两个文件是实时更新的，如果遇到这种情况，maser服务器特别繁忙，
那么这两个文件会被频繁的修改，那么I/0的性能一定会下降
mysql> show global variables like "sync%";+---------------------+-------+| Variable_name | Value |+---------------------+-------+| sync_binlog | 0 || sync_frm | ON || sync_master_info | 0 || sync_relay_log | 0 || sync_relay_log_info | 0 |+---------------------+-------+5 rows in set (0.05 sec)
为了复制的安全性：
sync_master_info = 1 sync_relay_log = 1 sync_relay_log_info = 1
安装percona-toolkit
[root@localhost home]# yum install ./percona-toolkit-2.2.4-1.noarch.rpm
使用方法
[root@localhost home]# pt-heartbeat -h[root@localhost home]# pt 工具这么多pt-agent pt-fingerprint pt-pmp pt-table-checksumpt-align pt-fk-error-logger pt-query-digest pt-table-syncpt-archiver pt-heartbeat pt-show-grants pt-table-usagept-config-diff pt-index-usage pt-sift pt-upgradept-deadlock-logger pt-ioprofile pt-slave-delay pt-variable-advisorpt-diskstats pt-kill pt-slave-find pt-visual-explainpt-duplicate-key-checker pt-mext pt-slave-restart ptxpt-fifo-split pt-mysql-summary pt-stalk pt-find pt-online-schema-change pt-summary
查看配置信息
[root@localhost home]# pt-summary # Percona Toolkit System Summary Report ###################### Date | 2015-10-17 09:25:30 UTC (local TZ: CST +0800) Hostname | localhost.localdomain Uptime | 11:59, 3 users, load average: 0.00, 0.00, 0.00 Platform | Linux Release | CentOS release 6.7 (Final) Kernel | 2.6.32-573.el6.x86_64Architecture | CPU = 64-bit, OS = 64-bit Threading | NPTL 2.12 SELinux | Enforcing Virtualized | VMWare# Processor ################################################## Processors | physical = 2, cores = 4, virtual = 4, hyperthreading = no Speeds | 4x2195.089 Models | 4xIntel(R) Core(TM) i3-2328M CPU @ 2.20GHz Caches | 4x3072 KB# Memory ##################################################### Total | 2.0G Free | 1.5G Used | physical = 487.5M, swap allocated = 2.1G, swap used = 0.0, virtual = 487.5M Buffers | 50.1M Caches | 181.6M Dirty | 12 kB UsedRSS | 157.0M Swappiness | 60 DirtyPolicy | 20, 10 DirtyStatus | 0, 0# Mounted Filesystems ######################################## Filesystem Size Used Type Opts Mountpoint /dev/mapper/VolGroup-lv_home 37G 1% ext4 rw /home /dev/mapper/VolGroup-lv_root 50G 5% ext4 rw / /dev/sda1 477M 9% ext4 rw /boot tmpfs 1002M 0% tmpfs rw,rootcontext="system_u:object_r:tmpfs_t:s0" /dev/shm# Disk Schedulers And Queue Size ############################# dm-0 | 128 dm-1 | 128 dm-2 | 128 sda | [cfq] 128 sr0 | [cfq] 128# Disk Partioning ############################################Device Type Start End Size============ ==== ========== ========== ==================/dev/dm-0 Disk 53687091200/dev/dm-1 Disk 2248146944/dev/dm-2 Disk 40173043712/dev/sda Disk 96636764160/dev/sda1 Part 1 64 518192640/dev/sda2 Part 64 11749 96112396800/dev/sr0 Disk 3895459840/dev/sr0p1 Part 1 3715 15577645056# Kernel Inode State #########################################dentry-state | 45417 37192 45 0 0 0 file-nr | 768 0 200279 inode-nr | 41113 103# LVM Volumes ################################################ LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert lv_home VolGroup -wi-ao---- 37.41g lv_root VolGroup -wi-ao---- 50.00g lv_swap VolGroup -wi-ao---- 2.09g # LVM Volume Groups ########################################## VG VSize VFree VolGroup 89.51g 0 # RAID Controller ############################################ Controller | No RAID controller detected# Network Config ############################################# FIN Timeout | 60 Port Range | 61000# Interface Statistics ####################################### interface rx_bytes rx_packets rx_errors tx_bytes tx_packets tx_errors ========= ========= ========== ========== ========== ========== ========== lo 900 20 0 900 20 0 eth0 7000000 20000 0 5000000 17500 0# Network Devices ############################################ Device Speed Duplex ========= ========= ========= eth0 1000Mb/s Full # Network Connections ######################################## Connections from remote IP addresses 192.168.81.1 3 192.168.81.133 1 Connections to local IP addresses 192.168.81.132 4 Connections to top 10 local ports 22 3 50606 1 States of connections ESTABLISHED 4 LISTEN 5# Top Processes ############################################## PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 1 root 20 0 19232 1520 1228 S 0.0 0.1 0:03.21 init 2 root 20 0 0 0 0 S 0.0 0.0 0:00.04 kthreadd 3 root RT 0 0 0 0 S 0.0 0.0 0:00.61 migration/0 4 root 20 0 0 0 0 S 0.0 0.0 0:00.30 ksoftirqd/0 5 root RT 0 0 0 0 S 0.0 0.0 0:00.00 stopper/0 6 root RT 0 0 0 0 S 0.0 0.0 0:00.19 watchdog/0 7 root RT 0 0 0 0 S 0.0 0.0 0:00.80 migration/1 8 root RT 0 0 0 0 S 0.0 0.0 0:00.00 stopper/1 9 root 20 0 0 0 0 S 0.0 0.0 0:00.12 ksoftirqd/1# Notable Processes ########################################## PID OOM COMMAND11078 -17 sshd# Simplified and fuzzy rounded vmstat (wait please) ########## procs ---swap-- -----io---- ---system---- --------cpu-------- r b si so bi bo ir cs us sy il wa st 1 0 0 0 1 1 5 6 0 0 100 0 0 0 0 0 0 35 0 2250 1250 4 9 88 0 0 0 0 0 0 0 0 7 10 0 0 100 0 0 0 0 0 0 0 250 25 45 0 0 100 0 0 0 0 0 0 0 0 8 15 0 0 100 0 0# The End ####################################################
从服务器意外崩溃时，建议使用pt-slave-start命令来启动slave;
基于行和基于语句复制：
基于语句：
数据量小；易于查看；适应性强；
有些语句无法做精确复制；无法对使用了触发器、存储过程等代码的应用实现精确复制；
基于行：
能够精确完成有着触发器、存储过程等代码场景中的复制；能完成几乎所有的复制功能；较少的CPU占用率；
无法判断执行了什么样的SQL语句；数据量可能略大；
从服务器落后于主服务器：
Seconds_Behind_Master: 0
查看落后时长，如果落后，请观测此值
mysql> show slave status\G
Seconds_Behind_Master: 0
如果数据不一致，解决办法
1、重新备份并在从服务器导入数据；
2、pt-table-sync
为了提高复制时的数据安全性，在主服务器上的设定：
sync_binlog = 1
innodb_flush_log_at_trx_commit = 1
此参数的值设定为1，性能下降会较严重；因此，一般设定为2等，
此时，主服务器崩溃依然有可能导致从服务器无法获取到全部的二进制日志事件；
如果master意外崩溃导致二进制日志中的某事件损坏，可以在从服务器使用如下参数忽略：
sql_slave_skip_counter = 0
第三方复制解决方案：Tungsten, Galera
复制要考虑的事儿：
何为雪崩效应?
如何缓存,高效命中缓存？[轮巡，对Sql语句hash取模？]
从服务器写入的压力并不比主服务器的压力小，
事务的手动自动提交，频繁同步到磁盘、
二进制日志文件的频繁写入读出，中继日志的写入读出，
SQl I/O <---> Slave 单线程忙碌
从服务器落后于主服务器的必然，
中途断电，缓存中的二进制文件未写入到磁盘，怎么办？
长途跨地，如何同步数据？
有了这位么多的从服务器，数据还需要备份吗？
2015.10.18