OneProxy实现MySQL分库分表

简介
Part1:随着网站的壮大，MySQL数据库架构一般会经历一个过程：

数据量比较小的时候，一台单实例数据库足矣。等数据量增大的时，会采用一主多从的数据库架构来降低读写io。当某张业务表达到几百万上千万甚至上亿时，就应该去进行分表处理。本文演示OneProxy对数据库实现分表处理，对前端应用是透明的。

Part2:环境简介
HE1:192.168.1.248 Master1
HE3:192.168.1.250 Master2
HE4:192.168.1.251 Oneproxy

环境构建
Part1:安装Oneproxy
Oneproxy的安装不是本文讲述的重点，需要的可移步至
OneProxy实现MySQL读写分离与负载均衡
http://suifu.blog.51cto.com/9167728/1884673

Part2:proxy.cnf
proxy.cnf文件是oneproxy的主要参数配置文件，新版的oneproxy对整个目录进行了重新的划分，配置文件都放在了conf目录里
[root@HE4 oneproxy]# cat conf/proxy.conf
[oneproxy]
keepalive = 1
event-threads = 4
log-file = log/oneproxy.log
pid-file = log/oneproxy.pid
lck-file = log/oneproxy.lck
mysql-version = 5.7.16
proxy-address = :3307
proxy-master-addresses.1 = 192.168.1.248:3306@group1
proxy-master-addresses.2 = 192.168.1.250:3306@group2
proxy-user-list = sys_admin/1C6D087BA5D2607A27DECB2F2AFE247E911E877A@test
proxy-part-tables.1 = /root/oneproxy/conf/part.txt
#proxy-part-tables.2 = /root/oneproxy/conf/part2.txt
proxy-charset = utf8_bin
proxy-group-policy.1 = group1:master-only
proxy-group-policy.2 = group2:master-only
proxy-secure-client = 192.168.1.248
proxy-sequence.1 = default
proxy-httpserver = :8080
proxy-httptitle = OneProxy Monitor

Part3:part.txt
part.txt文件是分区策略配置文件，在本博文中，采取hash分区来进行简单演示
[root@HE4 oneproxy]# cat conf/part.txt
[
{
"table" : "helei",
"pkey" : "id",
"type" : "int",
"method" : "hash",
"partitions" :
[
{ "suffix" : "_0", "group": "group1" },
{ "suffix" : "_1", "group": "group2" },
{ "suffix" : "_2", "group": "group1" },
{ "suffix" : "_3", "group": "group2"}
]
}
]

实战
Part1:启动OneProxy
[root@HE4 oneproxy]# ./oneproxy.service start
Starting OneProxy ... [ OK ]

Part2:监控页面两台Master

Part3:创建相关表
登录oneproxy管理库创建表
[root@HE1 ~]# mysql -usys_admin -pMANAGER -h192.168.1.251 -P3307 test
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 103
Server version: 5.7.16 OneProxy-Community-5.8.5 (OneXSoft)
Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> create table helei(
-> id int(10) unsigned NOT NULL AUTO_INCREMENT,
-> c1 int(10) NOT NULL DEFAULT '0',
-> c2 int(10) unsigned DEFAULT NULL,
-> c5 int(10) unsigned NOT NULL DEFAULT '0',
-> c3 timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
-> c4 varchar(200) NOT NULL DEFAULT '',
-> PRIMARY KEY(id),
-> KEY idx_c1(c1),
-> KEY idx_c2(c2)
-> )ENGINE=InnoDB ;
Query OK, 0 rows affected (0.27 sec)
mysql> \q

Part4:插入数据
[root@HE1 ~]# mysql -usys_admin -pMANAGER -h192.168.1.251 -P3307 test -e"insert into helei(id,c1,c2,c5,c4) values(1,1,1,1,'1')"
mysql: [Warning] Using a password on the command line interface can be insecure.

[root@HE1 ~]# mysql -usys_admin -pMANAGER -h192.168.1.251 -P3307 test -e"insert into helei(id,c1,c2,c5,c4) values(2,2,2,2,'2')"
mysql: [Warning] Using a password on the command line interface can be insecure.

[root@HE1 ~]# mysql -usys_admin -pMANAGER -h192.168.1.251 -P3307 test -e"insert into helei(id,c1,c2,c5,c4) values(3,3,3,3,'3')"
mysql: [Warning] Using a password on the command line interface can be insecure.

[root@HE1 ~]# mysql -usys_admin -pMANAGER -h192.168.1.251 -P3307 test -e"insert into helei(id,c1,c2,c5,c4) values(4,4,4,4,'4')"
mysql: [Warning] Using a password on the command line interface can be insecure.

校验
Part1:校验oneproxy表内容
这里可以看到虚拟表helei中已经具有刚刚插入的内容；
[root@HE1 ~]# mysql -usys_admin -pMANAGER -h192.168.1.251 -P3307 test -e"select * from helei";
mysql: [Warning] Using a password on the command line interface can be insecure.
+----+----+------+----+---------------------+----+
| id | c1 | c2 | c5 | c3 | c4 |
+----+----+------+----+---------------------+----+
| 4 | 4 | 4 | 4 | 2016-12-23 00:07:21 | 4 |
| 1 | 1 | 1 | 1 | 2016-12-23 16:07:04 | 1 |
| 2 | 2 | 2 | 2 | 2016-12-23 00:07:10 | 2 |
| 3 | 3 | 3 | 3 | 2016-12-23 16:07:16 | 3 |
+----+----+------+----+---------------------+----+

Part2:校验Master1中的内容
[root@HE1 ~]# mysql -uroot -pMANAGER test
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 158
Server version: 5.7.16-log MySQL Community Server (GPL)
Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> show tables;
+----------------+
| Tables_in_test |
+----------------+
| checksums |
| helei_0 |
| helei_2 |
| sbtest |
+----------------+
4 rows in set (0.00 sec)

mysql> select * from helei_0;
+----+----+------+----+---------------------+----+
| id | c1 | c2 | c5 | c3 | c4 |
+----+----+------+----+---------------------+----+
| 4 | 4 | 4 | 4 | 2016-12-23 00:07:21 | 4 |
+----+----+------+----+---------------------+----+
1 row in set (0.00 sec)

mysql> select * from helei_2;
+----+----+------+----+---------------------+----+
| id | c1 | c2 | c5 | c3 | c4 |
+----+----+------+----+---------------------+----+
| 2 | 2 | 2 | 2 | 2016-12-23 00:07:10 | 2 |
+----+----+------+----+---------------------+----+
1 row in set (0.00 sec)

Part3:校验Master2中的内容
[root@HE3 ~]# mysql -uroot -pMANAGER test
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 2997
Server version: 5.7.16-log MySQL Community Server (GPL)
Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> show tables;
+----------------+
| Tables_in_test |
+----------------+
| checksums |
| helei_1 |
| helei_3 |
+----------------+
3 rows in set (0.00 sec)

mysql> select * from helei_1;
+----+----+------+----+---------------------+----+
| id | c1 | c2 | c5 | c3 | c4 |
+----+----+------+----+---------------------+----+
| 1 | 1 | 1 | 1 | 2016-12-23 16:07:04 | 1 |
+----+----+------+----+---------------------+----+
1 row in set (0.00 sec)

mysql> select * from helei_3;
+----+----+------+----+---------------------+----+
| id | c1 | c2 | c5 | c3 | c4 |
+----+----+------+----+---------------------+----+
| 3 | 3 | 3 | 3 | 2016-12-23 16:07:16 | 3 |
+----+----+------+----+---------------------+----+
1 row in set (0.00 sec)

注意
Warning:警告1
不支持预编译语句 PreparedStatement,不支持Bind、Execute调用接口。

Warning:警告2
不支持使用use命令来切换后端数据库，use命令可执行，但其含义是切换到不同的MySQL主备集群，OneProxy在支持分库分表功能后，就将一个主备集群视为一个数据库了，链接Oneproxy时如果指定了数据库名，则需替换成Server Group的名字

Warning:警告3
禁止使用set命令，任何set命令都会直接返回成功，而不做任何处理。

Warning:警告4
默认禁止CALL、PREPARE、EXECUTE、DEALLOCATE命令，不支持存储过程和函数。

Warning:警告5
OneProxy支持master进行故障转移切换，但建议采用流行的高可用方案MHA实现。故障切换后，OneProxy可以自动识别哪台机器是master。另外，架构必须是一主带N从，不能是双主带N从。

——总结——
至此，OneProxy对MySQL的分库分表测试完成，对于前端应用而言，表名是透明的。无需变更代码。由于笔者的水平有限，编写时间也很仓促，文中难免会出现一些错误或者不准确的地方，不妥之处恳请读者批评指正。

参考文献：
http://hcymysql.blog.51cto.com/5223301/1685146
http://www.onexsoft.com