Mycat的简易安装及测试

1.环境
OS版本  CentOS release 6.5 (Final)  64bit
DB版本  Mysql 5.6.37
Mycat   1.6
jdk1.7及以上版本

2.实战部署
1.创建用户及用户组
[root@mysql01 ~]# groupadd mycat
[root@mysql01 ~]# useradd -g mycat mycat

2.上传解压JDK
Java Oracle官方下载地址为： http://www.oracle.com/technetwork/java/javase/archive-139210.html 
[mycat@mysql01 ~]$ tar zxvf jdk-7u80-linux-x64.tar.gz
3.上传解压mycat
[mycat@mysql01 ~]$ tar zxvf Mycat-server-1.6-RELEASE-20161028204710-linux.tar.gz

4.指定目录安装mycat及jdk
[root@mysql01 mycat]# mv mycat /usr/local/
[root@mysql01 mycat]# mv jdk1.7.0_80 /usr/local/mycat/

5.配置jdk环境变量
export JAVA_HOME=/usr/local/mycat/jdk1.7.0_80
export PATH=$JAVA_HOME/bin:$PATH
export CLASSPATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar

6.创建测试库(mycat 对db1 db2 db3做了默认配置)
mysql> create database db1;
mysql> create database db2;
mysql> create database db3;

7.配置mycat到数据库的连接(schema.xml)
#手动测试 通过url user password 能链接到测试库
<writeHost host="hostM1" url="localhost:3306" user="root" password="123456">

8.启动mycat
[mycat@mysql01 bin]$ ./mycat start
Starting Mycat-server...
[mycat@mysql01 bin]$

日志抛出异常
[mycat@mysql01 logs]$ more wrapper.log
STATUS | wrapper  | 2017/09/27 22:34:57 | --> Wrapper Started as Daemon
STATUS | wrapper  | 2017/09/27 22:34:57 | Launching a JVM...
ERROR  | wrapper  | 2017/09/27 22:35:03 | JVM exited while loading the application.
INFO   | jvm 1    | 2017/09/27 22:35:03 | Error: Exception thrown by the agent : java.net.MalformedURLException: Local host name unknown: java.net.UnknownHostException
: mysql01: mysql01: Name or service not known
STATUS | wrapper  | 2017/09/27 22:35:07 | Launching a JVM...
[mycat@mysql01 logs]$

9.修改hosts文件，绑定主机名
[root@mysql01 3306]# vi /etc/hosts
127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6

127.0.0.1   mysql01

10.再次启动mycat
[mycat@mysql01 bin]$ ./mycat start
Starting Mycat-server...
[mycat@mysql01 bin]$

日志未见异常，启动成功
[mycat@mysql01 bin]$ ps -ef|grep mycat
mycat     3374     1  0 22:39 ?        00:00:00 /usr/local/mycat/bin/./wrapper-

3.测试
1.利用mycat连接mysql数据库
#在mysql系统用户下执行登陆，此时的mysql相当于客户端
[mysql@mysql01 ~]$ mysql -uroot -p123456 -h127.0.0.1 -P8066 -DTESTDB
Warning: Using a password on the command line interface can be insecure.
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 5.6.29-mycat-1.6-RELEASE-20161028204710 MyCat Server (OpenCloundDB)

Copyright (c) 2000, 2017, 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>

其中8066是mycat的监听端口，其中-u，-p，-h分别是用户名，密码和主机，-D是连接的逻辑库。
这里的端口，用户名，密码，逻辑库都是在 server.xml 文件中配置的

2.创建Travelrecord表
mysql> create table travelrecord (id bigint not null primary key,user_id varchar(100),traveldate DATE, fee decimal,days int);
Query OK, 0 rows affected (0.20 sec)
mysql>
至于表名为什么是travelrecord，这个和配置文件schema.xml的配置有关

3.插入数据
mysql> insert into travelrecord(id,user_id,traveldate,fee,days)  values(1,'Victor',20160101,100,10);
mysql> insert into travelrecord(id,user_id,traveldate,fee,days)  values(5000001,'Job',20160102,100,10);
mysql> insert into travelrecord(id,user_id,traveldate,fee,days)  values(10000001,'Slow',20160103,100,10);
mysql>
至于ID为什么取三个值，这个与conf目录下autopartition-long.txt的定义有关，这个文件主要定义auto-sharding-long的规则。
这里主要是测试在id取不同区间的值时，分片的效果。

4.查看分片效果
#重新登陆到mysql上查询（不要通过mycat查询）
[mysql@mysql01 ~]$ mysql -uroot -p123456 -h 127.0.0.1 -P 3306

mysql> select * from db1.travelrecord;
+----+---------+------------+------+------+
| id | user_id | traveldate | fee  | days |
+----+---------+------------+------+------+
|  1 | Victor  | 2016-01-01 |  100 |   10 |
+----+---------+------------+------+------+
1 row in set (0.00 sec)

mysql> select * from db2.travelrecord;
+---------+---------+------------+------+------+
| id      | user_id | traveldate | fee  | days |
+---------+---------+------------+------+------+
| 5000001 | Job     | 2016-01-02 |  100 |   10 |
+---------+---------+------------+------+------+
1 row in set (0.00 sec)

mysql> select * from db3.travelrecord;
+----------+---------+------------+------+------+
| id       | user_id | traveldate | fee  | days |
+----------+---------+------------+------+------+
| 10000001 | Slow    | 2016-01-03 |  100 |   10 |
+----------+---------+------------+------+------+
1 row in set (0.00 sec)

mysql>

数据分片插入成功

4.查看MyCAT具体会将数据分配到哪个节点上

mysql>  explain insert into travelrecord(id,user_id,traveldate,fee,days)  values(1,'Victor',20160101,100,10);
+-----------+----------------------------------------------------------------------------------------------+
| DATA_NODE | SQL                                                                                          |
+-----------+----------------------------------------------------------------------------------------------+
| dn1       | insert into travelrecord(id,user_id,traveldate,fee,days)  values(1,'Victor',20160101,100,10) |
+-----------+----------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)

mysql> explain insert into travelrecord(id,user_id,traveldate,fee,days)  values(5000001,'Job',20160102,100,10);
+-----------+-------------------------------------------------------------------------------------------------+
| DATA_NODE | SQL                                                                                             |
+-----------+-------------------------------------------------------------------------------------------------+
| dn2       | insert into travelrecord(id,user_id,traveldate,fee,days)  values(5000001,'Job',20160102,100,10) |
+-----------+-------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)

mysql> explain insert into travelrecord(id,user_id,traveldate,fee,days)  values(10000001,'Slow',20160103,100,10);
+-----------+---------------------------------------------------------------------------------------------------+
| DATA_NODE | SQL                                                                                               |
+-----------+---------------------------------------------------------------------------------------------------+
| dn3       | insert into travelrecord(id,user_id,traveldate,fee,days)  values(10000001,'Slow',20160103,100,10) |
+-----------+---------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)

mysql>

语法其实蛮简单，就是SQL语句前加上explain语句

5.关于配置文件，conf目录下主要以下三个需要熟悉

server.xml是Mycat服务器参数调整和用户授权的配置文件
schema.xml是逻辑库定义和表以及分片定义的配置文件
rule.xml是分片规则的配置文件