• mysql远程表/视图-应用


    Date :20140213
    Auth: Jin
    参考
    http://blog.sina.com.cn/s/blog_757b0e130101erl5.html
    http://dev.mysql.com/doc/refman/5.1/zh/storage-engines.html#federated-storage-engine

    一、问题描述
    1.目前应用情况
    在mysql 3304实例中有phpcms,anquanzuo两个库,
    phpcms有数据写入,anquanzu没有数据写入
    anquanzu有一个视图表carseats_article 为phpcms库的三个表v9_news,v9_news_data,v9_category组合的视图
    3304-anquanzuo>show create table carseats_articleG
    *************************** 1. row ***************************
    View: carseats_article
    Create View: CREATE ALGORITHM=UNDEFINED DEFINER=`dbselect`@`192.168.201.201` SQL SECURITY DEFINER VIEW `carseats_article` AS select `a`.`id` AS `id`,`a`.`title` AS `title`,`a`.`catid` AS `module_id`,`a`.`thumb` AS `img`,`c`.`catname` AS `module_name`,`b`.`content` AS `content`,`a`.`username` AS `publish_user`,`a`.`status` AS `is_del`,`a`.`listorder` AS `order`,`a`.`updatetime` AS `update_time`,`a`.`inputtime` AS `add_time`,`b`.`copyfrom` AS `copyfrom`,`a`.`keywords` AS `keywords`,`a`.`islink` AS `islink`,`a`.`url` AS `url` from ((`phpcms`.`v9_news` `a` join `phpcms`.`v9_news_data` `b`) join `phpcms`.`v9_category` `c`) where ((`a`.`catid` = `c`.`catid`) and (`a`.`id` = `b`.`id`))
    character_set_client: utf8
    collation_connection: utf8_general_ci
    1 row in set (0.00 sec)

    2、数据迁移
    phpcms 迁移到mmm集群
    anquanzuo 迁移至NDB Cluster (两台数据节点245,246,管理节点247)

    3,问题
    迁移anquanzuo库时无法创建carseats_article,因为phpcms库不在一个实例了

    4、解决办法
    以前SQL Server工作有用到DB link远程库
    而mysql支持远程表
    1)在phpcms创建需要的视图
    2)在anquanzuo上创建远程表

    二、创建mmm上phpcms的视图
    到mmm的master服务器上
    $ jump 121
    # mysql -h 127.0.0.1 -P 3304 -u root -pjpasswd2011 phpcms
    1、创建视图
    DROP VIEW IF EXISTS `v_carseats_article`;
    CREATE VIEW `v_carseats_article` AS
    SELECT
    `a`.`id` AS `id`,
    `a`.`title` AS `title`,
    `a`.`catid` AS `module_id`,
    `a`.`thumb` AS `img`,
    `c`.`catname` AS `module_name`,
    `b`.`content` AS `content`,
    `a`.`username` AS `publish_user`,
    `a`.`status` AS `is_del`,
    `a`.`listorder` AS `order`,
    `a`.`updatetime` AS `update_time`,
    `a`.`inputtime` AS `add_time`,
    `b`.`copyfrom` AS `copyfrom`,
    `a`.`keywords` AS `keywords`,
    `a`.`islink` AS `islink`,
    `a`.`url` AS `url`
    FROM ((`v9_news` AS `a` JOIN `v9_news_data` AS `b`) JOIN `v9_category` AS `c`)
    WHERE ((`a`.`catid` = `c`.`catid`) AND (`a`.`id` = `b`.`id`));

    确认视图可以查询数据
    3304-phpcms>select id,title from v_carseats_article limit 1;
    +-------+-----------------------------------------+
    | id | title |
    +-------+-----------------------------------------+
    | 96325 | 孩子们,圣诞老人真的存在! |
    +-------+-----------------------------------------+
    1 row in set (0.00 sec)

    2、授权访问
    grant select on phpcms.* to 'dbselect'@'192.168.201.%' identified by 'dmlpasswd'
    注:线上已经有权限


    三、修改NDB cluster支持FEDERATED [已准备好]
    1、确实是否已经支持
    $ jump 245
    $ jump 246
    mysql -S /mysql/dev/data4/mysql.sock -pjpasswd2013
    mysql> select version();
    +------------+
    | version() |
    +------------+
    | 5.5.30-log |
    +------------+
    mysql> show engines;
    +--------------------+---------+----------------------------------------------------------------+--------------+------+------------+
    | Engine | Support | Comment | Transactions | XA | Savepoints |
    +--------------------+---------+----------------------------------------------------------------+--------------+------+------------+
    | CSV | YES | CSV storage engine | NO | NO | NO |
    | MRG_MYISAM | YES | Collection of identical MyISAM tables | NO | NO | NO |
    | MyISAM | YES | MyISAM storage engine | NO | NO | NO |
    | BLACKHOLE | YES | /dev/null storage engine (anything you write to it disappears) | NO | NO | NO |
    | MEMORY | YES | Hash based, stored in memory, useful for temporary tables | NO | NO | NO |
    | PERFORMANCE_SCHEMA | YES | Performance Schema | NO | NO | NO |
    | ARCHIVE | YES | Archive storage engine | NO | NO | NO |
    | FEDERATED | NO | Federated MySQL storage engine | NULL | NULL | NULL |
    | InnoDB | DEFAULT | Supports transactions, row-level locking, and foreign keys | YES | YES | YES |
    +--------------------+---------+----------------------------------------------------------------+--------------+------+------------+

    使用show engines 命令查看数据库是否已支持FEDERATED引擎:
    Support 的值有以下几个:
    YES 支持并开启
    DEFAULT 支持并开启, 并且为默认引擎
    NO 不支持
    DISABLED 支持,但未开启

    2、修改246
    $ jump 247
    1)确认信息
    [root@JQ-pdt-host-247 ~]# ndb_mgm -e show
    Connected to Management Server at: localhost:1186
    Cluster Configuration
    ---------------------
    [ndbd(NDB)] 2 node(s)
    id=20 @192.168.201.245 (mysql-5.5.30 ndb-7.2.12, Nodegroup: 0, Master)
    id=21 @192.168.201.246 (mysql-5.5.30 ndb-7.2.12, Nodegroup: 0,)

    [ndb_mgmd(MGM)] 1 node(s)
    id=10 @192.168.201.247 (mysql-5.5.30 ndb-7.2.12)

    [mysqld(API)] 4 node(s)
    id=30 @192.168.201.245 (mysql-5.5.30 ndb-7.2.12) ### 这里
    id=31 @192.168.201.246 (mysql-5.5.30 ndb-7.2.12) ### 这里
    id=32 (not connected, accepting connect from any host)
    id=33 (not connected, accepting connect from any host)

    2)停止从
    [root@JQ-pdt-host-247 ~]# ndb_mgm ndb_mgm
    ndb_mgm> 21 STOP
    或者
    [root@JQ-pdt-host-246 ~]# mysqld_multi report 3
    Reporting MySQL servers
    MySQL server from group: mysqld3 is running
    [root@JQ-pdt-host-246 ~]# mysqld_multi stop 3 --password=jpasswd2011
    [root@JQ-pdt-host-246 ~]# mysqld_multi report 3
    Reporting MySQL servers
    MySQL server from group: mysqld3 is not running


    3)修改配置
    [root@JQ-pdt-host-246 ~]# vim /etc/my.cnf
    删除默认参数
    skip-federated
    打开
    [mysqld3]
    federated

    4)启动
    [root@JQ-pdt-host-246 ~]# mysqld_multi report 3
    Reporting MySQL servers
    MySQL server from group: mysqld3 is running

    5)确认生效
    mysql> show engines;
    +--------------------+---------+----------------------------------------------------------------+--------------+------+------------+
    | Engine | Support | Comment | Transactions | XA | Savepoints |
    +--------------------+---------+----------------------------------------------------------------+--------------+------+------------+
    | ndbcluster | DEFAULT | Clustered, fault-tolerant tables | YES | NO | NO |
    | CSV | YES | CSV storage engine | NO | NO | NO |
    | MRG_MYISAM | YES | Collection of identical MyISAM tables | NO | NO | NO |
    | ndbinfo | YES | MySQL Cluster system information storage engine | NO | NO | NO |
    | BLACKHOLE | YES | /dev/null storage engine (anything you write to it disappears) | NO | NO | NO |
    | FEDERATED | YES | Federated MySQL storage engine | NO | NO | NO |
    | ARCHIVE | YES | Archive storage engine | NO | NO | NO |
    | MyISAM | YES | MyISAM storage engine | NO | NO | NO |
    | InnoDB | YES | Supports transactions, row-level locking, and foreign keys | YES | YES | YES |
    | PERFORMANCE_SCHEMA | YES | Performance Schema | NO | NO | NO |
    | MEMORY | YES | Hash based, stored in memory, useful for temporary tables | NO | NO | NO |
    +--------------------+---------+----------------------------------------------------------------+--------------+------+------------+

    3、修改245
    jump 245
    同样的方法修改245
    root@JQ-pdt-host-245 ~]# mysql -h127.0.0.1 -P3303 -uroot -pjpasswd2011
    确认
    mysql> show engines;
    +--------------------+---------+----------------------------------------------------------------+--------------+------+------------+
    | Engine | Support | Comment | Transactions | XA | Savepoints |
    +--------------------+---------+----------------------------------------------------------------+--------------+------+------------+
    | ndbcluster | DEFAULT | Clustered, fault-tolerant tables | YES | NO | NO |
    | CSV | YES | CSV storage engine | NO | NO | NO |
    | MRG_MYISAM | YES | Collection of identical MyISAM tables | NO | NO | NO |
    | ndbinfo | YES | MySQL Cluster system information storage engine | NO | NO | NO |
    | BLACKHOLE | YES | /dev/null storage engine (anything you write to it disappears) | NO | NO | NO |
    | FEDERATED | YES | Federated MySQL storage engine | NO | NO | NO |
    | ARCHIVE | YES | Archive storage engine | NO | NO | NO |
    | MyISAM | YES | MyISAM storage engine | NO | NO | NO |
    | InnoDB | YES | Supports transactions, row-level locking, and foreign keys | YES | YES | YES |
    | PERFORMANCE_SCHEMA | YES | Performance Schema | NO | NO | NO |
    | MEMORY | YES | Hash based, stored in memory, useful for temporary tables | NO | NO | NO |
    +--------------------+---------+----------------------------------------------------------------+--------------+------+------------+
    11 rows in set (0.00 sec)


    四、数据迁移

    1、导出数据
    cd /home/backup
    mysqldump -h192.168.201.210 -P3304 anquanzuo > anquanzuo_source_20140213.sql

    2、修改数据并导入
    cp anquanzuo_source_20140213.sql anquanzuo_ndb_20140213.sql

    sed -i s/MyISAM/ndbcluster/ anquanzuo_source_20140213.sql
    sed -i s/InnoDB/ndbcluster/anquanzuo_source_20140213.sql

    删除anquanzuo_ndb_20140213.sql文件中 carseats_article创建语句,或者前面dump前就先删除 carseats_article视图
    这不如果没有依赖前面的远程表则可以先做
    mysql> use anquanzuo;
    Database changed
    mysql> source ./anquanzuo_ndb_20140213.sql;
    ERROR 1146 (42S02): Table 'phpcms.v9_news' doesn't exist
    清理不是很干净
    mysql> show tables;
    +----------------------------+
    | Tables_in_anquanzuo |
    +----------------------------+
    | carseats_evaluation_report |
    | carseats_goods |
    | carseats_topic |
    | carseats_topic_comment |
    +----------------------------+
    4 rows in set (0.01 sec)

    把原来的远程表删了

    把下面-- Final view structure for view `carseats_article`
    也删除
    后发现还报错phpcms.v9_news

    这个步骤放在前面在创建远程表

    确认246是否同步

    3、准备远程表
    -- 在anquanzuo上调整,注意调整ip
    --drop table carseats_article;
    mysql> create database anquanzuo;
    mysql> use anquanzuo;
    Database changed

    create table carseats_article (
    id mediumint(8) unsigned,
    title varchar(80),
    module_id smallint(5) unsigned,
    img varchar(100),
    module_name varchar(30),
    content mediumtext,
    publish_user char(20),
    is_del varchar(2),
    `order` int(10) unsigned,
    update_time int(10) unsigned,
    add_time int(10) unsigned,
    copyfrom varchar(100),
    keywords varchar(255),
    islink tinyint(1) unsigned,
    url varchar(255)
    ) ENGINE=FEDERATED CONNECTION='mysql://dbselec:dmlpasswd@192.168.201.121:3304/phpcms/v_carseats_article';

    ip选择vip或者其他ip都可以

    mysql> show tables;
    +---------------------+
    | Tables_in_anquanzuo |
    +---------------------+
    | carseats_article |
    +---------------------+
    1 row in set (0.00 sec)

    查询
    mysql> select id,title from carseats_article limit 1;
    +-------+-----------------------------------------+
    | id | title |
    +-------+-----------------------------------------+
    | 96325 | 孩子们,圣诞老人真的存在! |
    +-------+-----------------------------------------+
    1 row in set (45.47 sec)

    另外一台246确认
    [root@JQ-pdt-host-246 ~]# mysql -h127.0.0.1 -P3303 -uroot -pjpasswd2011 anquanzuo
    mysql> show tables;
    Empty set (0.00 sec)
    可以见FEDERATED 存储引擎是不同步的
    因为查询时两台都有可能查询到,所以246这台也要创建;
    注意:

    root@JQ-pdt-host-246 ~]# ll /data/mysql/data3/anquanzuo/
    total 16
    -rw-rw---- 1 mysql mysql 9068 Feb 13 16:59 carseats_article.frm
    -rw-rw---- 1 mysql mysql 61 Feb 13 16:50 db.opt

    除了ENGINE选项应该是FEDERATED, 并且CONNECTION表选项是给FEDERATED指明如何连接到远程服务器上的连接字符串之外, 这个表的结构必须完全与远程表的结构相同.


    五、总结
    1、开启支持FEDERATED存储引擎,默认不知道
    2、NDB cluster中不会同步远程表,因为不是NDBcluster存储引擎,所以每个SQL节点都要创建一次远程表,不然当使用到那个节点时候表不存在
    3、远程表或视图需要先存在
    4、FEDERATED支持及不支持的如下:
    ·远程服务器必须是一个MySQL服务器. FEDERATED对其它数据库引擎的支持可能会在将来被添加.
    ·FEDERATED表指向的远程表在通过FEDERATED表访问它之前必须存在.
    ·一个FEDERATED表指向另一个FEDERATED表是可能的, 但是必须小心不要创建一个循环.
    ·没有对事务的支持.
    ·如果远程表已经改变, 对FEDERATED引擎而言是没有办法知道的. 这个的原因是因为这个表必须象数据文件一样工作,
    除了数据库其它任何都不会被写入. 如果有任何对远程数据库的改变, 本地表中数据的完整性可能会被破坏.
    ·FEDERATED存储引擎支持SELECT,INSERT,UPDATE,DELETE和索引. 它不支持ALTER TABLE,DROP TABLE或任何
    其它的数据定义语言语句. 当前的实现不使用预先准备好的语句.
    ·执行使用SELECT,INSERT,UPDATE和DELETE, 但不用HANDLER.
    ·FEDERATED表不能对查询缓存不起作用.
    这些限制中的一些在FEDERATED处理机的将来版本可能被消除.

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  • 原文地址:https://www.cnblogs.com/diege/p/3548445.html
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