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