#### 業務場景：
公司幾個主要的業務已經獨立，放在不同的數據庫服務器上面，但是有一個業務又需要關聯多個業務庫進行聯合查詢統計。這時候就需要將不同的業務庫數據同步到一臺從庫進行統計。根據Mysql主從同步原理使用多從一主的方案解決。主庫使用innodb引擎，從庫開啓多實例使用myisam引擎並將多個實例的數據同步到同一個目錄，並通過flush tables 在一個實例裏面訪問其他實例的數據。
#### 解決思路：
1、主數據庫使用Innodb引擎，並設置sql_mode爲 NO_AUTO_CREATE_USER
2、從庫開啓多實例，將多個主庫裏面的數據通過主從複製同步到同一個數據目錄。從庫的每個實例對應一個主庫。多個實例使用同一個數據目錄。
3、從庫使用Myisam引擎，關閉從庫默認的innodb引擎,Myisam引擎可以訪問同一個數據目錄裏面其他實例的表。
4、從庫的每個實例需要執行flush tables 才能看到其他實例表的數據變化，可以設置crontab任務計劃每分鐘在第一個實例刷新表，以便程序連接的默認實例能看到表的實時變化。
5、設置主庫和從庫的sql_mode都爲NO_AUTO_CREATE_USER，只有這樣主庫的innodb引擎的sql同步到從庫的時候才能執行成功。
#### 方案架構圖：
#### 環境說明：
主庫-1：192.168.1.1
主庫-2：192.168.1.2
從庫-3：192.168.1.3
從庫-3：192.168.1.4
從庫-3：192.168.1.5
#### 實現步驟：（Mysql安裝步驟這裏不在描述）
1、主數據庫配置文件，多個主庫配置文件除了server-id不能一樣其他都一樣。
[root@masterdb01 ~]#cat /etc/my.cnf [client] port= 3306 socket= /tmp/mysql.sock [mysqld] port = 3306 basedir = /usr/local/mysql datadir = /data/mysql character-set-server = utf8mb4 default-storage-engine = InnoDB socket = /tmp/mysql.sock skip-name-resolv = 1 open_files_limit = 65535 back_log = 103 max_connections = 512 max_connect_errors = 100000 table_open_cache = 2048 tmp-table-size = 32M max-heap-table-size = 32M #query-cache-type = 0 query-cache-size = 0 external-locking = FALSE max_allowed_packet = 32M sort_buffer_size = 2M join_buffer_size = 2M thread_cache_size = 51 query_cache_size = 32M tmp_table_size = 96M max_heap_table_size = 96M query_cache_type=1 log-error=/data/logs/mysqld.log slow_query_log = 1 slow_query_log_file = /data/logs/slow.log long_query_time = 0.1 # BINARY LOGGING # server-id = 1 log-bin = /data/binlog/mysql-bin log-bin-index =/data/binlog/mysql-bin.index expire-logs-days = 14 sync_binlog = 1 binlog_cache_size = 4M max_binlog_cache_size = 8M max_binlog_size = 1024M log_slave_updates #binlog_format = row binlog_format = MIXED //這裏使用的混合模式複製 relay_log_recovery = 1 #不需要同步的表 replicate-wild-ignore-table=mydb.sp_counter #不需要同步的庫 replicate-ignore-db = mysql,information_schema,performance_schema key_buffer_size = 32M read_buffer_size = 1M read_rnd_buffer_size = 16M bulk_insert_buffer_size = 64M myisam_sort_buffer_size = 128M myisam_max_sort_file_size = 10G myisam_repair_threads = 1 myisam_recover transaction_isolation = REPEATABLE-READ innodb_additional_mem_pool_size = 16M innodb_buffer_pool_size = 5734M innodb_buffer_pool_load_at_startup = 1 innodb_buffer_pool_dump_at_shutdown = 1 innodb_data_file_path = ibdata1:1024M:autoextend innodb_flush_log_at_trx_commit = 2 innodb_log_buffer_size = 32M innodb_log_file_size = 2G innodb_log_files_in_group = 2 innodb_io_capacity = 4000 innodb_io_capacity_max = 8000 innodb_max_dirty_pages_pct = 50 innodb_flush_method = O_DIRECT innodb_file_format = Barracuda innodb_file_format_max = Barracuda innodb_lock_wait_timeout = 10 innodb_rollback_on_timeout = 1 innodb_print_all_deadlocks = 1 innodb_file_per_table = 1 innodb_locks_unsafe_for_binlog = 0 [mysqldump] quick max_allowed_packet = 32M
2、從庫配置文件。多個從庫配置文件除了server-id不能一樣其他都一樣。
[root@slavedb01 ~]# cat /etc/my.cnf [client] port= 3306 socket= /tmp/mysql.sock [mysqld_multi] # 指定相關命令的路徑 mysqld = /usr/local/mysql/bin/mysqld_safe mysqladmin = /usr/local/mysql/bin/mysqladmin ##複製主庫1的數據## [mysqld2] port = 3306 basedir = /usr/local/mysql datadir = /data/mysql character-set-server = utf8mb4 #指定實例1的sock文件和pid文件 socket = /tmp/mysql.sock pid-file=/data/mysql/mysql.pid skip-name-resolv = 1 open_files_limit = 65535 back_log = 103 max_connections = 512 max_connect_errors = 100000 table_open_cache = 2048 tmp-table-size = 32M max-heap-table-size = 32M query-cache-size = 0 external-locking = FALSE max_allowed_packet = 32M sort_buffer_size = 2M join_buffer_size = 2M thread_cache_size = 51 query_cache_size = 32M tmp_table_size = 96M max_heap_table_size = 96M query_cache_type=1 #指定第一個實例的錯誤日誌和慢查詢日誌路徑 log-error=/data/logs/mysqld.log slow_query_log = 1 slow_query_log_file = /data/logs/slow.log long_query_time = 0.1 # BINARY LOGGING# # 指定實例1的binlog和relaylog路徑爲/data/binlog目錄 # 每個從庫和每個實例的server_id不能一樣。 server-id = 2 log-bin = /data/binlog/mysql-bin log-bin-index =/data/binlog/mysql-bin.index relay_log = /data/binlog/mysql-relay-bin relay_log_index = /data/binlog/mysql-relay.index master-info-file = /data/mysql/master.info relay_log_info_file = /data/mysql/relay-log.info read_only = 1 expire-logs-days = 14 sync_binlog = 1 #需要同步的庫，如果不設置，默認同步所有庫。 #replicate-do-db = xxx #不需要同步的表 replicate-wild-ignore-table=mydb.sp_counter #不需要同步的庫 replicate-ignore-db = mysql,information_schema,performance_schema binlog_cache_size = 4M max_binlog_cache_size = 8M max_binlog_size = 1024M log_slave_updates =1 #binlog_format = row binlog_format = MIXED relay_log_recovery = 1 key_buffer_size = 32M read_buffer_size = 1M read_rnd_buffer_size = 16M bulk_insert_buffer_size = 64M myisam_sort_buffer_size = 128M myisam_max_sort_file_size = 10G myisam_repair_threads = 1 myisam_recover #設置默認引擎爲Myisam，下面這些參數一定要加上。 default-storage-engine=MyISAM default-tmp-storage-engine=MYISAM #關閉innodb引擎 skip-innodb innodb = OFF disable-innodb #設置sql_mode模式爲NO_AUTO_CREATE_USER sql_mode = NO_AUTO_CREATE_USER #關閉innodb引擎 loose-skip-innodb loose-innodb-trx=0 loose-innodb-locks=0 loose-innodb-lock-waits=0 loose-innodb-cmp=0 loose-innodb-cmp-per-index=0 loose-innodb-cmp-per-index-reset=0 loose-innodb-cmp-reset=0 loose-innodb-cmpmem=0 loose-innodb-cmpmem-reset=0 loose-innodb-buffer-page=0 loose-innodb-buffer-page-lru=0 loose-innodb-buffer-pool-stats=0 loose-innodb-metrics=0 loose-innodb-ft-default-stopword=0 loose-innodb-ft-inserted=0 loose-innodb-ft-deleted=0 loose-innodb-ft-being-deleted=0 loose-innodb-ft-config=0 loose-innodb-ft-index-cache=0 loose-innodb-ft-index-table=0 loose-innodb-sys-tables=0 loose-innodb-sys-tablestats=0 loose-innodb-sys-indexes=0 loose-innodb-sys-columns=0 loose-innodb-sys-fields=0 loose-innodb-sys-foreign=0 loose-innodb-sys-foreign-cols=0 ##複製主庫2的數據## [mysqld3] port = 3307 basedir = /usr/local/mysql datadir = /data/mysql character-set-server = utf8mb4 #指定實例2的sock文件和pid文件 socket = /tmp/mysql3.sock pid-file=/data/mysql/mysql3.pid skip-name-resolv = 1 open_files_limit = 65535 back_log = 103 max_connections = 512 max_connect_errors = 100000 table_open_cache = 2048 tmp-table-size = 32M max-heap-table-size = 32M query-cache-size = 0 external-locking = FALSE max_allowed_packet = 32M sort_buffer_size = 2M join_buffer_size = 2M thread_cache_size = 51 query_cache_size = 32M tmp_table_size = 96M max_heap_table_size = 96M query_cache_type=1 log-error=/data/logs/mysqld3.log slow_query_log = 1 slow_query_log_file = /data/logs/slow3.log long_query_time = 0.1 # BINARY LOGGING # # 這裏一定要注意，不能把兩個實例的binlog和relaylog放到同一個目錄， # 這裏指定實例2的binlog日誌爲/data/binlog2目錄 # 每個從庫和每個實例的server_id不能一樣。 server-id = 22 log-bin = /data/binlog2/mysql-bin log-bin-index =/data/binlog2/mysql-bin.index relay_log = /data/binlog2/mysql-relay-bin relay_log_index = /data/binlog2/mysql-relay.index master-info-file = /data/mysql/master3.info relay_log_info_file = /data/mysql/relay-log3.info read_only = 1 expire-logs-days = 14 sync_binlog = 1 #不需要複製的庫 replicate-ignore-db = mysql,information_schema,performance_schema binlog_cache_size = 4M max_binlog_cache_size = 8M max_binlog_size = 1024M log_slave_updates =1 #binlog_format = row binlog_format = MIXED relay_log_recovery = 1 key_buffer_size = 32M read_buffer_size = 1M read_rnd_buffer_size = 16M bulk_insert_buffer_size = 64M myisam_sort_buffer_size = 128M myisam_max_sort_file_size = 10G myisam_repair_threads = 1 myisam_recover #設置默認引擎爲Myisam default-storage-engine=MyISAM default-tmp-storage-engine=MYISAM #關閉innodb引擎 skip-innodb innodb = OFF disable-innodb #設置sql_mode模式爲NO_AUTO_CREATE_USER sql_mode = NO_AUTO_CREATE_USER #關閉innodb引擎，下面這些參數一定要加上。 loose-skip-innodb loose-innodb-trx=0 loose-innodb-locks=0 loose-innodb-lock-waits=0 loose-innodb-cmp=0 loose-innodb-cmp-per-index=0 loose-innodb-cmp-per-index-reset=0 loose-innodb-cmp-reset=0 loose-innodb-cmpmem=0 loose-innodb-cmpmem-reset=0 loose-innodb-buffer-page=0 loose-innodb-buffer-page-lru=0 loose-innodb-buffer-pool-stats=0 loose-innodb-metrics=0 loose-innodb-ft-default-stopword=0 loose-innodb-ft-inserted=0 loose-innodb-ft-deleted=0 loose-innodb-ft-being-deleted=0 loose-innodb-ft-config=0 loose-innodb-ft-index-cache=0 loose-innodb-ft-index-table=0 loose-innodb-sys-tables=0 loose-innodb-sys-tablestats=0 loose-innodb-sys-indexes=0 loose-innodb-sys-columns=0 loose-innodb-sys-fields=0 loose-innodb-sys-foreign=0 loose-innodb-sys-foreign-cols=0 [mysqldump] quick max_allowed_packet = 32M ```
3、設置主庫sql_mode,Mysql5.6默認需要在啓動文件文件裏面設置sql_mode纔可以生效。
# cat /etc/init.d/mysqld #other_args="$*" # uncommon, but needed when called from an RPM upgrade action # Expected: "--skip-networking --skip-grant-tables" # They are not checked here, intentionally, as it is the resposibility # of the "spec" file author to give correct arguments only. #將上面默認的#other_args開啓後改爲 other_args="--sql-mode=NO_AUTO_CREATE_USER"
4、開啓主庫和從庫
#主庫 service mysqld start #開啓從庫的二個實例 /usr/local/mysql/bin/mysqld_multi start 2 /usr/local/mysql/bin/mysqld_multi start 3
5、在兩臺主庫上面分別授權複製賬號
#需要授權三個從庫的ip可以同步 mysql> GRANT REPLICATION SLAVE ON *.* TO rep@'192.168.1.3' IDENTIFIED BY 'rep123'; mysql> GRANT REPLICATION SLAVE ON *.* TO rep@'192.168.1.4' IDENTIFIED BY 'rep123'; mysql> GRANT REPLICATION SLAVE ON *.* TO rep@'192.168.1.5' IDENTIFIED BY 'rep123'; mysql> flush privileges;
6、在三個從庫分別開啓同步。
#進入第一個實例執行 $ mysql -S /tmp/mysql.sock mysql> CHANGE MASTER TO MASTER_HOST='192.168.1.1',MASTER_USER='rep',MASTER_PASSWORD='rep123',MASTER_LOG_FILE='mysql-bin.000001',MASTER_LOG_POS=112; #進入第二個實例執行 $ mysql -S /tmp/mysql3.sock mysql> CHANGE MASTER TO MASTER_HOST='192.168.1.2',MASTER_USER='rep',MASTER_PASSWORD='rep123',MASTER_LOG_FILE='mysql-bin.000001',MASTER_LOG_POS=112;
7、測試數據同步
在二個主數據庫分別建表和插入數據，到從庫查看可以看到二個主庫同步到同一個從庫上面的所有數據。
8、在每臺從庫服務器上設置任務計劃每分鐘刷新第一個實例的表
# crontab -l */1 * * * * mysql -S /tmp/mysql.sock -e 'flush tables;'
Mysql5.6多主一從的坑
1、Mysql5.6默認的引擎是innodb默認同步的時候一定要把主和從的sql_mode模式裏面的NO_ENGINE_SUBSTITUTION這個參數關閉。如果不關閉innodb同步到從庫上面的sql將會找不到innodb引擎導致同步失敗。
2、在mysql5.6開啓多實例的時候第一次啓動的時候在你數據庫的安裝目錄裏面（/usr/local/mysql/)會生成my.cnf配置文件，默認會優先讀取數據庫安裝目錄裏面的配置文件。導致多實例不生效。