中小型企業可參考的類MySQL雙主架構方案
作者：燕十三
主從同步一般都是一個主庫,一旦主庫出現問題,就有可能直接導致整個主從同步架構崩盤,雖然發現后也是可以慢慢恢復的,但是這個恢復時間對于很多公司來說是難以接受的,今天的這篇博文就是主要給解決主庫單點故障這個問題提供一個思路。
在企業中,一般系統架構的瓶頸會出現在數據庫這一部分,mysql主從架構在很大程度上解決了這部分瓶頸,但是在mysql主從同步的架構也存在很多問題；比如:1. 關于數據寫入部分(也就是主庫)往往很難做到擴展,雖然很多大公司在邏輯業務方面就進行對數據的拆分,比如商品庫存按照區域去拆分(一個區域走一個庫存也就是一個主庫,然后定時同步總的庫存),按照商品類型去劃分(一個類型的商品走一套數據庫),但是這對于很多中小型公司來說實現起來還是比較困難的； 2. 主從同步一般都是一個主庫,一旦主庫出現問題,就有可能直接導致整個主從同步架構崩盤,雖然發現后也是可以慢慢恢復的,但是這個恢復時間對于很多公司來說是難以接受的,今天的這篇博文就是主要給解決主庫單點故障這個問題提供一個思路:
主要思路是:
1.一臺主庫(我們稱之為master-01)提供服務,只負責數據的寫入；
2.拿出一臺數據庫服務器(我們稱之為Master-02)資源做master-01主庫的從庫(之間做主從同步)；
3.兩臺主庫之間做高可用,可以采用keepalived等方案(一定要保證master-01同時也要作為keepalived的主)
4.程序在調用主庫IP地址的地方寫為高可用的VIP地址；
5.所有提供服務的從服務器與master-02進行主從同步；
6.建議采用高可用策略的時候,當master-01出現問題切換到master-02的時候,即使master-01恢復了,也不要讓它去自動承接VIP地址,否則可能造成數據的混寫；
這樣做可以在一定程度上保證主庫的高可用,在一臺主庫down掉之后,可以在極短的時間內切換到另一臺主庫上(盡可能減少主庫宕機對業務造成的影響),減少了主從同步給線上主庫帶來的壓力；但是也有幾個不足的地方:比如master-02可能會一直處于空閑狀態(其實完全可以讓它承擔一部分從庫的角色來負責一部分查詢請求的),2. 這樣真正提供服務的從庫要等master-02先同步完了數據后才能去master-02上去同步數據,這樣可能會造成一定程度的同步延遲時間的加長；3. 如果master-01一旦恢復正常,會不會導致數據寫入混亂(這個可以在keepalived中設置響應的規則,讓其不”奪權”,我們認為的去調整操作即可
架構的簡易圖如下:
具體實施方案:
1. 在所有需要提供服務的服務器上安裝MySQL服務(建議源碼安裝)
1.1 yum安裝依賴包
- yum -y install cmake make gcc gcc-c++ ncurses-devel bison openssl-devel
1.2 添加MySQL所需要的用戶/組
- groupadd mysql
- useradd -g mysql -r mysql
1.3 下載MySQL源碼包
- wget http://dev.mysql.com/get/Downloads/MySQL-5.5/mysql-5.5.36.tar.gz
1.4 創建MySQL安裝所需要的目錄
- mkdir /data/mydata/{data,tmp,logs} –pv
1.5 解壓編譯安裝MySQL
- tar xf mysql-5.5.36.tar.gz
- cd mysql-5.5.36
- cmake . -DCMAKE_INSTALL_PREFIX=/usr/local/mysql \
- -DMYSQL_DATADIR=/data/mydata/data \
- -DSYSCINFDIR=/etc \
- -DWITH_INNOBASE_STORAGE_ENGINE=1 \
- -DWITH_ARCHIVE_STORAGE_ENGINE=1 \
- -DWITH_BLACKHOLE_STORAGE_ENGINE=1 \
- -DWITH_READLINE=1 \
- -DWITH_SSL=system \
- -DWITH_ZLIB=system \
- -DWITH_LIBWARP=0 \
- -DWITH_UNIX_ADDR=/tmp/mysql.sock \
- -DDEFAULT_CHARASET=uft8 \
- -DDEFAULT_COLLATTON=utf9_general_ci \
- make && make install
1.6 為MySQL提供啟動腳本
- cp support-files/mysql.server /etc/rc.d/init.d/mysqld
1.7 為master-01主庫提供配置文件(32G內存較為保守(滿連接占用25G左右內存)的配置文件）
- [client]
- port = 3306
- socket = /var/lib/mysql/mysql.sock
- default-character-set = utf-8
- [mysqld]
- server-id = 1
- port = 3306
- user = mysql
- basedir = /usr/local/mysql
- datadir = /data/mydata/data
- tmpdir = /data/mydata/tmp
- socket = /var/lib/mysql/mysql.sock
- skip-external-locking
- skip-name-resolve
- default-storage-engine = INNODB
- character-set-server = utf8
- wait-timeout = 100
- connect_timeout = 20
- interactive_timeout = 100
- back_log = 300
- myisam_recover
- event_scheduler = on
- log-bin=/data/mydata/logs/mysql-bin
- binlog_format = row
- max_binlog_size = 64M
- binlog_cache_size = 1M
- slave-net-timeout = 10
- skip-slave-start
- slow_query_log = 1
- long_query_time = 1
- slow_query_log_file = /data/mydata/mysqllog/logs/mysql.slow
- log-error = /data/mydata/mysqllog/logs/error.log
- max_connections = 1000
- max_user_connections = 1000
- max_connect_errors = 10000
- key_buffer_size = 32M #以MyISAM為主的服務器,要調大此值
- max_allowed_packet = 64M
- table_cache = 4096
- table_open_cache = 4096
- table_definition_cache = 4096
- sort_buffer_size = 512K
- read_buffer_size = 512K
- read_rnd_buffer_size = 512K
- join_buffer_size = 512K
- tmp_table_size = 64M
- max_heap_table_size = 64M
- query_cache_type = 0
- query_cache_size = 0
- bulk_insert_buffer_size = 16M
- thread_cache_size = 64
- thread_concurrency = 16 #CPU核數*2
- thread_stack = 256K
- innodb_data_home_dir = /data/mydata/data
- innodb_log_group_home_dir = /data/mydata/mysqllog/logs
- innodb_data_file_path = ibdata1:1G:autoextend
- innodb_buffer_pool_size = 16G
- innodb_buffer_pool_instances = 4
- innodb_additional_mem_pool_size = 16M
- innodb_log_file_size = 512M
- innodb_log_buffer_size = 32M
- innodb_log_files_in_group = 3
- innodb_flush_log_at_trx_commit = 2
- innodb_lock_wait_timeout = 10
- innodb_sync_spin_loops = 40
- innodb_max_dirty_pages_pct = 90
- innodb_support_xa = 1
- innodb_thread_concurrency = 0
- innodb_thread_sleep_delay = 500
- innodb_file_io_threads = 4
- innodb_concurrency_tickets = 1000
- log_bin_trust_function_creators = 1
- innodb_flush_method = O_DIRECT
- innodb_file_per_table #是否采用單表單空間
- innodb_write_io_threads = 8
- innodb_read_io_threads = 8
- innodb_io_capacity = 1000
- innodb_file_format = Barracuda #不開啟單表單空間,此選項無效
- innodb_purge_threads = 1
- innodb_purge_batch_size = 32
- innodb_old_blocks_pct = 75
- innodb_change_buffering = all
- transaction_isolation = READ-COMMITTED
- [mysqldump]
- quick
- max_allowed_packet = 32M
- [mysql]
- no-auto-rehash
- [myisamchk]
- key_buffer_size = 64M
- sort_buffer_size = 256M
- read_buffer = 2M
- write_buffer = 2M
- [mysqlhotcopy]
- interactive-timeout
- [mysqld_safe]
- open-files-limit = 10240
1.8 為master-02提供配置文件
- master-02的配置文件僅需在master-01上稍作修改
- server-id = 20
- log_slave_updates = 1 #添加(將復制事件寫入binlog,一臺服務器既做主庫又做從庫此選項必須要開啟)
- replicate-same-server-id=0 #添加(防止MySQL循環更新)
- relay_log_recovery = 1 #添加(MySQLrelay_log的自動修復功能)
1.9 為從庫提供配置文件(8G)
- [client]
- port = 3306
- socket = /var/lib/mysql/mysql.sock
- default-character-set = utf8
- [mysqld]
- server-id = 2
- port = 3306
- user = mysql
- basedir = /usr/local/mysql
- datadir = /data/mydata/data
- tmpdir = /data/mydata/tmp
- socket = /var/lib/mysql/mysql.sock
- skip-external-locking
- skip-name-resolve
- default-storage-engine = INNODB
- character-set-server = utf8
- wait-timeout = 100
- connect_timeout = 20
- interactive_timeout = 100
- back_log = 300
- myisam_recover
- event_scheduler = on
- log-bin=/data/mydata/logs/mysql-bin
- binlog_format = row
- max_binlog_size = 64M
- binlog_cache_size = 1M
- slave-net-timeout = 10
- relay_log_recovery = 1
- slow_query_log = 1
- long_query_time = 1
- slow_query_log_file = /data/mydata/mysqllog/logs/mysql.slow
- log-error = /data/mydata/mysqllog/logs/error.log
- max_connections = 500
- max_user_connections = 500
- max_connect_errors = 10000
- key_buffer_size = 32M #以MyISAM為主的服務器,要調大此值
- max_allowed_packet = 64M
- table_cache = 2048
- table_open_cache = 2048
- table_definition_cache = 2048
- sort_buffer_size = 128K
- read_buffer_size = 128K
- read_rnd_buffer_size = 128K
- join_buffer_size = 128K
- tmp_table_size = 16M
- max_heap_table_size = 16M
- query_cache_type = 0
- query_cache_size = 0
- bulk_insert_buffer_size = 16M
- thread_cache_size = 64
- thread_concurrency = 4 #CPU核數*2
- thread_stack = 128K
- innodb_data_home_dir = /data/mydata/data
- innodb_log_group_home_dir = /data/mydata/mysqllog/logs
- innodb_data_file_path = ibdata1:1G:autoextend
- innodb_buffer_pool_size = 2G
- innodb_buffer_pool_instances = 4
- innodb_additional_mem_pool_size = 4M
- innodb_log_file_size = 512M
- innodb_log_buffer_size = 16M
- innodb_log_files_in_group = 3
- innodb_flush_log_at_trx_commit = 2
- innodb_lock_wait_timeout = 10
- innodb_sync_spin_loops = 40
- innodb_max_dirty_pages_pct = 90
- innodb_support_xa = 1
- innodb_thread_concurrency = 0
- innodb_thread_sleep_delay = 500
- innodb_file_io_threads = 4
- innodb_concurrency_tickets = 1000
- log_bin_trust_function_creators = 1
- innodb_flush_method = O_DIRECT
- innodb_file_per_table #是否采用單表單空間
- innodb_write_io_threads = 8
- innodb_read_io_threads = 8
- innodb_io_capacity = 1000
- innodb_file_format = Barracuda #不開啟單表單空間,此選項無效
- innodb_purge_threads = 1
- innodb_purge_batch_size = 32
- innodb_old_blocks_pct = 75
- innodb_change_buffering = all
- transaction_isolation = READ-COMMITTED
- [mysqldump]
- quick
- max_allowed_packet = 32M
- [mysql]
- no-auto-rehash
- [myisamchk]
- key_buffer_size = 64M
- sort_buffer_size = 256M
- read_buffer = 2M
- write_buffer = 2M
- [mysqlhotcopy]
- interactive-timeout
- [mysqld_safe]
- open-files-limit = 10240
1.10 初始化MySQL
- /usr/local/mysql/scripts/mysql_install_db --user=mysql --datadir=/data/mydata/data/ --basedir=/usr/local/mysql
1.11 為啟動腳本賦予可執行權限并啟動MySQL
- chmod +x /etc/rc.d/init.d/mysqld
- /etc/init.d/mysqld start
2. 配置master-01
2.1 添加主從同步賬戶
- mysql> grant replication slave on *.* to 'repl'@'192.168.237.%' idetified by '123456'；
- mysql> flush privileges；
2.2 查看主庫的狀態
- mysql> show master status；
- +------------------+----------+--------------+------------------+
- | File | Position | Binlog_Do_DB | Binlog_Ignore_DB |
- +------------------+----------+--------------+------------------+
- | mysql-bin.000009 | 652 | | |
- +------------------+----------+--------------+------------------+
- 1 row in set (0.01 sec)
2.3 因為這是測試環境,可以保證沒數據寫入,否則需要先鎖表-->查看狀態-->備份數據-->查看狀態(保證沒變)-->解鎖表
3. 配置master-02
3.1 配置master-02為master-01的從
- #若是線上有數據需要先導入數據
- mysql> CHANGE MASTER TO
- -> MASTER_HOST='192.168.237.128',
- -> MASTER_PORT=3306,
- -> MASTER_USER='repl',
- -> MASTER_PASSWORD='123456',
- -> MASTER_LOG_FILE='mysql-bin.000009',
- -> MASTER_LOG_POS=652；
- Query OK, 0 rows affected (0.03 sec)
- mysql> start slave；
- mysql> show slave status \G
- Slave_IO_Running: Yes #確保為yes
- Slave_SQL_Running: Yes #確保為yes
3.2 配置master-02的同步用戶
- mysql> grant replication slave on *.* to 'repl’@’192.168.237.%' identified by '123456'；
- mysql> flush privileges；
3.3 查看master-02的狀態
- mysql> show master status；
- +------------------+----------+--------------+------------------+
- | File | Position | Binlog_Do_DB | Binlog_Ignore_DB |
- +------------------+----------+--------------+------------------+
- | mysql-bin.000004 | 689 | | |
- +------------------+----------+--------------+------------------+
- 1 row in set (0.00 sec)
4. 從庫根據上面步驟配置為master-02的從即可(為了節省篇幅不再一一贅述)
5. 在master-01上創建一個數據庫測試同步效果
6. 去master-02跟從庫上分別查看是否已經同步過數據來
好了,至此數據同步已經完成,關于keepalived實現雙主高可用,我會在下篇keepalived實現MySQL高可用總給大家寫出!!!
責任編輯：林師授
來源：
51CTO博客
