我们在容器启动4个mysql实例，docker-compose.xml 内容如下：
version: '3.7'
services:
mysql8_1:
image: "mysql:8.0.19"
container_name: mysql8_1
ports:
- "33080:3306"
environment:
MYSQL_ROOT_PASSWORD: 12345678
mysql8_2:
image: "mysql:8.0.19"
container_name: mysql8_2
ports:
- "33081:3306"
environment:
MYSQL_ROOT_PASSWORD: 12345678
mysql8_3:
image: "mysql:8.0.19"
container_name: mysql8_3
ports:
- "33082:3306"
environment:
MYSQL_ROOT_PASSWORD: 12345678
mysql8_4:
image: "mysql:8.0.19"
container_name: mysql8_4
ports:
- "33083:3306"
environment:
MYSQL_ROOT_PASSWORD: 12345678然后参照我《mysql5-主从同步配置》和 《mysql8多主一从配置》配置一下数据库的主从同步，完成后继续向下执行，如果你已经有了数据库集群切有主从同步，就不需要做上面的操作。
使用 docker 来启动一个 ShardingProxy
1、获取sharding-proxy的docker镜像
docker pull apache/sharding-proxy:4.0.12、配置文件在容器中的路径是/opt/sharding-proxy/conf，所以启动时可以在将此路径映射到容器外部，便于修改配置。
docker run -d -v /${your_work_dir}/conf:/opt/sharding-proxy/conf -e PORT=3308 -p13308:3308 --name shardingproxy apache/sharding-proxy:latest可以通过-e JVM_OPTS="" 环境变量指定JVM配置，通过映射/opt/sharding-proxy/ext-lib地址到宿主机来方便添加扩展jar包
本机举例，我执行的命令就是
docker run --name shardingProxy -d -v /home/yangyan/conf/sharding-proxy:/opt/sharding-proxy/conf -v /home/yangyan/conf/sharding-proxy/ext-lib:/opt/sharding-proxy/ext-lib -e PORT=3308 -p13308:3308 apache/sharding-proxy:latest容器启动后，查看日志，发现没有成功启动，缺少mysql的jdbc包，然后我们需要将jar复制到/opt/sharding-proxy/lib/目录下，因为我看了一下这个服务的start.sh脚本，加入到 classpath的路径有lib，但没有ext-lib这个目录，我就放到了lib下，而且我专门试了移动到ext-lib下面是会找不到驱动的。
然后我们增加配置文件 server.yaml 到 shardingProxy 的 conf 目录下
authentication:
users:
root:
password: root
props:
executor.size: 16
sql.show: true从简单开始，配置一个主从集群
增加 config-test.xml 到shardingProxy 的 conf 目录下
schemaName: master_slave_db
dataSources:
ds_master1:
url: jdbc:mysql://mysql8_1:3306/test?serverTimezone=UTC&characterEncoding=utf8&useUnicode=true&useSSL=false
username: root
password: 12345678
ds_slave1:
url: jdbc:mysql://mysql8_2:3306/test?serverTimezone=UTC&characterEncoding=utf8&useUnicode=true&useSSL=false
username: root
password: 12345678
ds_slave2:
url: jdbc:mysql://mysql8_3:3306/test?serverTimezone=UTC&characterEncoding=utf8&useUnicode=true&useSSL=false
username: root
password: 12345678
masterSlaveRule:
name: ds_ms
masterDataSourceName: ds_master1
slaveDataSourceNames:
- ds_slave1
- ds_slave2
loadBalanceAlgorithmType: ROUND_ROBIN容器启动失败，我遇到了两个问题：
问题１：因为我用的 mysql jdbc jar 包是 java8 编译的，shardingProxy 容器里面java环境是1.7，所以无法成功加载mysql jdbc 驱动，所以需要在容器中替换为 java8 的环境。
这里可以讲本地下载的java8目录通过 docker cp 命令复制到容器中：
docker cp ~/Downloads/java-1.8.0-openjdk-amd64 08343b40ab39:/usr/lib/jvm/对于 java 环境路径的处理，按正常来说应该是使用 update-java-alternatives命令比较方便，但是我这里一直无法运行成功，所以我就一条条的执行了创建链接
update-alternatives --install /usr/bin/idlj idlj /usr/lib/jvm/java-1.8.0-openjdk-amd64/bin/idlj 999
update-alternatives --install /usr/bin/wsimport wsimport /usr/lib/jvm/java-1.8.0-openjdk-amd64/bin/wsimport 999
update-alternatives --install /usr/bin/rmic rmic /usr/lib/jvm/java-1.8.0-openjdk-amd64/bin/rmic 999
update-alternatives --install /usr/bin/jinfo jinfo /usr/lib/jvm/java-1.8.0-openjdk-amd64/bin/jinfo 999
update-alternatives --install /usr/bin/jsadebugd jsadebugd /usr/lib/jvm/java-1.8.0-openjdk-amd64/bin/jsadebugd 999
update-alternatives --install /usr/bin/native2ascii native2ascii /usr/lib/jvm/java-1.8.0-openjdk-amd64/bin/native2ascii 999
update-alternatives --install /usr/bin/jstat jstat /usr/lib/jvm/java-1.8.0-openjdk-amd64/bin/jstat 999
update-alternatives --install /usr/bin/javac javac /usr/lib/jvm/java-1.8.0-openjdk-amd64/bin/javac 999
update-alternatives --install /usr/bin/javah javah /usr/lib/jvm/java-1.8.0-openjdk-amd64/bin/javah 999
update-alternatives --install /usr/bin/jps jps /usr/lib/jvm/java-1.8.0-openjdk-amd64/bin/jps 999
update-alternatives --install /usr/bin/jstack jstack /usr/lib/jvm/java-1.8.0-openjdk-amd64/bin/jstack 999
update-alternatives --install /usr/bin/jrunscript jrunscript /usr/lib/jvm/java-1.8.0-openjdk-amd64/bin/jrunscript 999
update-alternatives --install /usr/bin/javadoc javadoc /usr/lib/jvm/java-1.8.0-openjdk-amd64/bin/javadoc 999
update-alternatives --install /usr/bin/jhat jhat /usr/lib/jvm/java-1.8.0-openjdk-amd64/bin/jhat 999
update-alternatives --install /usr/bin/javap javap /usr/lib/jvm/java-1.8.0-openjdk-amd64/bin/javap 999
update-alternatives --install /usr/bin/jconsole jconsole /usr/lib/jvm/java-1.8.0-openjdk-amd64/bin/jconsole 999
update-alternatives --install /usr/bin/jar jar /usr/lib/jvm/java-1.8.0-openjdk-amd64/bin/jar 999
update-alternatives --install /usr/bin/xjc xjc /usr/lib/jvm/java-1.8.0-openjdk-amd64/bin/xjc 999
update-alternatives --install /usr/bin/schemagen schemagen /usr/lib/jvm/java-1.8.0-openjdk-amd64/bin/schemagen 999
update-alternatives --install /usr/bin/extcheck extcheck /usr/lib/jvm/java-1.8.0-openjdk-amd64/bin/extcheck 999
update-alternatives --install /usr/bin/jmap jmap /usr/lib/jvm/java-1.8.0-openjdk-amd64/bin/jmap 999
update-alternatives --install /usr/bin/appletviewer appletviewer /usr/lib/jvm/java-1.8.0-openjdk-amd64/bin/appletviewer 999
update-alternatives --install /usr/bin/jstatd jstatd /usr/lib/jvm/java-1.8.0-openjdk-amd64/bin/jstatd 999
update-alternatives --install /usr/bin/jdb jdb /usr/lib/jvm/java-1.8.0-openjdk-amd64/bin/jdb 999
update-alternatives --install /usr/bin/serialver serialver /usr/lib/jvm/java-1.8.0-openjdk-amd64/bin/serialver 999
update-alternatives --install /usr/bin/wsgen wsgen /usr/lib/jvm/java-1.8.0-openjdk-amd64/bin/wsgen 999
update-alternatives --install /usr/bin/jcmd jcmd /usr/lib/jvm/java-1.8.0-openjdk-amd64/bin/jcmd 999
update-alternatives --install /usr/bin/jarsigne jarsignerr /usr/lib/jvm/java-1.8.0-openjdk-amd64/bin/jarsigner 999我没有找到JAVA_HOME这个环境变量在哪个文件里配置的，不过这会执行java和javac已经是运行的jdk8的bin下的文件了，这一块不是本次关注的重点，生产环境时候的时候，确保不要出现java版本太低这种问题。你可以选择其他的方式安装java8到你的环境中。
问题2： 因为的创建mysql集群的时候使用的是单独的一个docker-compose文件，启动shardingProxy容器的时候是单独起的，所以mysql集群和shardingProxy的容器之间的网络是不通的，所以需要讲shardingProxy这个容器加入到myslq集群的网络中。
docker network connect mysql-cluster_default shardingProxy
执行后，进入shardingProxy去ping mysql 集群机器已经可以ping通了，上面一切正常后，我们持续输出日志，方便我们观察集群的执行情况。
docker logs -f shardingProxy
然后我们使用mysql客户端连接 shardingProxy
mycli -uroot -h 127.0.0.1 -P 13308 --database=master_slave_db
然后我们查询数据库，再插入一条数据
mysql root@127.0.0.1:master_slave_db> show tables;
+------------------+
| Tables_in_test |
|------------------|
| user |
+------------------+
1 row in set
Time: 0.009s
mysql root@127.0.0.1:master_slave_db> select * from user;
+------+-----------+
| id | name |
|------+-----------|
| 1 | xiaoming |
| 2 | xiaohong |
| 3 | xiaoling |
| 4 | xiaolizi2 |
| 5 | xiaowang |
+------+-----------+
5 rows in set
Time: 0.029s
mysql root@127.0.0.1:master_slave_db> insert into `user`(name) VALUES('dawang')
Query OK, 1 row affected
Time: 0.031s
docker的日志输出如下：
[INFO ] 13:42:53.324 [main] c.a.icatch.provider.imp.AssemblerImp - USING: com.atomikos.icatch.oltp_retry_interval = 10000
[INFO ] 13:42:53.324 [main] c.a.icatch.provider.imp.AssemblerImp - USING: java.naming.provider.url = rmi://localhost:1099
[INFO ] 13:42:53.324 [main] c.a.icatch.provider.imp.AssemblerImp - USING: com.atomikos.icatch.force_shutdown_on_vm_exit = false
[INFO ] 13:42:53.324 [main] c.a.icatch.provider.imp.AssemblerImp - USING: com.atomikos.icatch.default_jta_timeout = 300000
[INFO ] 13:42:53.325 [main] c.a.icatch.provider.imp.AssemblerImp - Using default (local) logging and recovery...
[INFO ] 13:42:53.347 [main] c.a.d.xa.XATransactionalResource - resource-1-ds_master1: refreshed XAResource
[INFO ] 13:42:53.366 [main] c.a.d.xa.XATransactionalResource - resource-2-ds_slave1: refreshed XAResource
[INFO ] 13:42:53.536 [epollEventLoopGroup-2-1] i.n.handler.logging.LoggingHandler - [id: 0x0a369872] REGISTERED
[INFO ] 13:42:53.537 [epollEventLoopGroup-2-1] i.n.handler.logging.LoggingHandler - [id: 0x0a369872] BIND: 0.0.0.0/0.0.0.0:3308
[INFO ] 13:42:53.539 [epollEventLoopGroup-2-1] i.n.handler.logging.LoggingHandler - [id: 0x0a369872, L:/0.0.0.0:3308] ACTIVE
tail: unrecognized file system type 0x794c7630 for ‘/opt/sharding-proxy/logs/stdout.log’. please report this to bug-coreutils@gnu.org. reverting to polling
[INFO ] 13:44:22.871 [epollEventLoopGroup-2-1] i.n.handler.logging.LoggingHandler - [id: 0x0a369872, L:/0.0.0.0:3308] READ: [id: 0xa355d100, L:/172.17.0.5:3308 - R:/172.17.0.1:58402]
[INFO ] 13:44:22.873 [epollEventLoopGroup-2-1] i.n.handler.logging.LoggingHandler - [id: 0x0a369872, L:/0.0.0.0:3308] READ COMPLETE
[INFO ] 13:44:26.566 [epollEventLoopGroup-2-1] i.n.handler.logging.LoggingHandler - [id: 0x0a369872, L:/0.0.0.0:3308] READ: [id: 0xf8e8f9e6, L:/172.17.0.5:3308 - R:/172.17.0.1:58442]
[INFO ] 13:44:26.566 [epollEventLoopGroup-2-1] i.n.handler.logging.LoggingHandler - [id: 0x0a369872, L:/0.0.0.0:3308] READ COMPLETE
[INFO ] 13:44:26.580 [epollEventLoopGroup-2-1] i.n.handler.logging.LoggingHandler - [id: 0x0a369872, L:/0.0.0.0:3308] READ: [id: 0x820865ab, L:/172.17.0.5:3308 - R:/172.17.0.1:58446]
[INFO ] 13:44:26.580 [epollEventLoopGroup-2-1] i.n.handler.logging.LoggingHandler - [id: 0x0a369872, L:/0.0.0.0:3308] READ COMPLETE
[INFO ] 13:44:27.209 [ShardingSphere-Command-2] ShardingSphere-SQL - Rule Type: master-slave
[INFO ] 13:44:27.209 [ShardingSphere-Command-2] ShardingSphere-SQL - SQL: SHOW TABLES ::: DataSources: ds_master1
[INFO ] 13:44:27.325 [ShardingSphere-Command-4] ShardingSphere-SQL - Rule Type: master-slave
[INFO ] 13:44:27.325 [ShardingSphere-Command-4] ShardingSphere-SQL - SQL: select TABLE_NAME, COLUMN_NAME from information_schema.columns
where table_schema = 'None'
order by table_name,ordinal_position ::: DataSources: ds_slave1
[INFO ] 13:48:26.249 [epollEventLoopGroup-2-1] i.n.handler.logging.LoggingHandler - [id: 0x0a369872, L:/0.0.0.0:3308] READ: [id: 0xea03ccca, L:/172.17.0.5:3308 - R:/172.17.0.1:60580]
[INFO ] 13:48:26.250 [epollEventLoopGroup-2-1] i.n.handler.logging.LoggingHandler - [id: 0x0a369872, L:/0.0.0.0:3308] READ COMPLETE
[INFO ] 13:48:29.239 [epollEventLoopGroup-2-1] i.n.handler.logging.LoggingHandler - [id: 0x0a369872, L:/0.0.0.0:3308] READ: [id: 0x8c998abc, L:/172.17.0.5:3308 - R:/172.17.0.1:60610]
[INFO ] 13:48:29.239 [epollEventLoopGroup-2-1] i.n.handler.logging.LoggingHandler - [id: 0x0a369872, L:/0.0.0.0:3308] READ COMPLETE
[INFO ] 13:48:30.602 [epollEventLoopGroup-2-1] i.n.handler.logging.LoggingHandler - [id: 0x0a369872, L:/0.0.0.0:3308] READ: [id: 0xc666fe46, L:/172.17.0.5:3308 - R:/172.17.0.1:60622]
[INFO ] 13:48:30.603 [epollEventLoopGroup-2-1] i.n.handler.logging.LoggingHandler - [id: 0x0a369872, L:/0.0.0.0:3308] READ COMPLETE
[INFO ] 13:48:31.742 [epollEventLoopGroup-2-1] i.n.handler.logging.LoggingHandler - [id: 0x0a369872, L:/0.0.0.0:3308] READ: [id: 0x2f66e703, L:/172.17.0.5:3308 - R:/172.17.0.1:60636]
[INFO ] 13:48:31.743 [epollEventLoopGroup-2-1] i.n.handler.logging.LoggingHandler - [id: 0x0a369872, L:/0.0.0.0:3308] READ COMPLETE
[INFO ] 13:48:31.759 [epollEventLoopGroup-2-1] i.n.handler.logging.LoggingHandler - [id: 0x0a369872, L:/0.0.0.0:3308] READ: [id: 0x62df3a93, L:/172.17.0.5:3308 - R:/172.17.0.1:60640]
[INFO ] 13:48:31.759 [epollEventLoopGroup-2-1] i.n.handler.logging.LoggingHandler - [id: 0x0a369872, L:/0.0.0.0:3308] READ COMPLETE
[INFO ] 13:48:31.782 [ShardingSphere-Command-6] ShardingSphere-SQL - Rule Type: master-slave
[INFO ] 13:48:31.782 [ShardingSphere-Command-6] ShardingSphere-SQL - SQL: SHOW TABLES ::: DataSources: ds_master1
[INFO ] 13:48:31.800 [ShardingSphere-Command-7] ShardingSphere-SQL - Rule Type: master-slave
[INFO ] 13:48:31.800 [ShardingSphere-Command-7] ShardingSphere-SQL - SQL: SELECT @@VERSION ::: DataSources: ds_slave1
[INFO ] 13:48:31.816 [ShardingSphere-Command-9] ShardingSphere-SQL - Rule Type: master-slave
[INFO ] 13:48:31.816 [ShardingSphere-Command-9] ShardingSphere-SQL - SQL: SELECT @@VERSION_COMMENT ::: DataSources: ds_slave1
[INFO ] 13:48:31.818 [ShardingSphere-Command-8] ShardingSphere-SQL - Rule Type: master-slave
[INFO ] 13:48:31.818 [ShardingSphere-Command-8] ShardingSphere-SQL - SQL: select TABLE_NAME, COLUMN_NAME from information_schema.columns
where table_schema = 'master_slave_db'
order by table_name,ordinal_position ::: DataSources: ds_slave1
[INFO ] 13:48:31.940 [ShardingSphere-Command-10] ShardingSphere-SQL - Rule Type: master-slave
[INFO ] 13:48:31.940 [ShardingSphere-Command-10] ShardingSphere-SQL - SQL: SELECT CONCAT("'", user, "'@'",host,"'") FROM mysql.user ::: DataSources: ds_slave1
[INFO ] 13:48:31.979 [ShardingSphere-Command-11] ShardingSphere-SQL - Rule Type: master-slave
[INFO ] 13:48:31.979 [ShardingSphere-Command-11] ShardingSphere-SQL - SQL: SELECT ROUTINE_NAME FROM INFORMATION_SCHEMA.ROUTINES
WHERE ROUTINE_TYPE="FUNCTION" AND ROUTINE_SCHEMA = "master_slave_db" ::: DataSources: ds_slave1
[INFO ] 13:48:32.010 [ShardingSphere-Command-12] ShardingSphere-SQL - Rule Type: master-slave
[INFO ] 13:48:32.010 [ShardingSphere-Command-12] ShardingSphere-SQL - SQL: SELECT name from mysql.help_topic WHERE name like "SHOW %" ::: DataSources: ds_slave1
[INFO ] 13:48:34.702 [ShardingSphere-Command-13] ShardingSphere-SQL - Rule Type: master-slave
[INFO ] 13:48:34.702 [ShardingSphere-Command-13] ShardingSphere-SQL - SQL: show tables ::: DataSources: ds_master1
[INFO ] 13:48:54.065 [ShardingSphere-Command-14] ShardingSphere-SQL - Rule Type: master-slave
[INFO ] 13:48:54.065 [ShardingSphere-Command-14] ShardingSphere-SQL - SQL: select * from user ::: DataSources: ds_slave1
[INFO ] 13:50:54.826 [ShardingSphere-Command-15] ShardingSphere-SQL - Rule Type: master-slave
[INFO ] 13:50:54.826 [ShardingSphere-Command-15] ShardingSphere-SQL - SQL: insert into `user`(name) VALUES('dawang') ::: DataSources: ds_master1
[INFO ] 14:04:00.439 [ShardingSphere-Command-0] ShardingSphere-SQL - Rule Type: master-slave
[INFO ] 14:04:00.439 [ShardingSphere-Command-0] ShardingSphere-SQL - SQL: select * from user ::: DataSources: ds_slave1
[INFO ] 14:04:08.809 [ShardingSphere-Command-1] ShardingSphere-SQL - Rule Type: master-slave
[INFO ] 14:04:08.809 [ShardingSphere-Command-1] ShardingSphere-SQL - SQL: select * from user ::: DataSources: ds_slave2
[INFO ] 14:05:15.457 [ShardingSphere-Command-2] ShardingSphere-SQL - Rule Type: master-slave
[INFO ] 14:05:15.457 [ShardingSphere-Command-2] ShardingSphere-SQL - SQL: select * from user ::: DataSources: ds_slave1
[INFO ] 14:05:15.833 [ShardingSphere-Command-3] ShardingSphere-SQL - Rule Type: master-slave
[INFO ] 14:05:15.833 [ShardingSphere-Command-3] ShardingSphere-SQL - SQL: select * from user ::: DataSources: ds_slave2
[INFO ] 14:05:16.270 [ShardingSphere-Command-4] ShardingSphere-SQL - Rule Type: master-slave
[INFO ] 14:05:16.270 [ShardingSphere-Command-4] ShardingSphere-SQL - SQL: select * from user ::: DataSources: ds_slave1
[INFO ] 14:05:16.851 [ShardingSphere-Command-5] ShardingSphere-SQL - Rule Type: master-slave
[INFO ] 14:05:16.851 [ShardingSphere-Command-5] ShardingSphere-SQL - SQL: select * from user ::: DataSources: ds_slave2
[INFO ] 14:05:17.151 [ShardingSphere-Command-6] ShardingSphere-SQL - Rule Type: master-slave
[INFO ] 14:05:17.151 [ShardingSphere-Command-6] ShardingSphere-SQL - SQL: select * from user ::: DataSources: ds_slave1
可以看出我们查询数据的时候走的是slave，插入数据的时候走的是 master，然后我执行了很多次的查询，走的都是 slave 节点，并且是在多个slave之间轮训着去查询。
当我们停掉启动一台slave的时候再执行查询，就会发现一次成功，一次失败。因为目前这个架构只是负载均衡，当一个slave出现问题的时候，目前是不会自动移除在这个有问题的slave的，当在轮训飘到这个已经无法连接的slave去执行的时候，会导致查询失败，飘到活着的那个slave的时候就会成功，所以我们下一步要增加故障转移，防止让请求飘到已经出问题的mysql实例上。
配置注册中心
首先我们启动一个 zookpper 实例，为了方便，此处还是使用 docker 来启动一个 zookeeper
docker run -p 2181:2181 --name zk --restart unless-stopped -d zookeeper因为 zookeeper 比较常用，占用的资源也很小，所以我用了 –restart unless-stopped，表示除非人工stop这个容器，否则这个容器每次都自动重启。
然后我们在 server.yaml 中增加以下配置：
orchestration:
name: orchestration_ds
overwrite: true
registry:
type: zookeeper
serverLists: 172.17.0.2:2181
namespace: orchestration这里的 serverLists 后面的就是 zookeeper 的地址，启动服务，就可以看到，我们的proxy实例已经注册到了zookeeper了。
sharding-ui（可选）
sharding-ui 是 shardingSphere官方辅助的一个用来数据治理的界面，github仓库地址是https://github.com/apache/incubator-shardingsphere，下载代码后，切换到4.0.1的分支(tag)，使用maven 编译前后端（sharding-ui-backend 和 sharding-ui-frontend）项目，然后启动，默认密码是 admin/admin，登录后需要添加注册中心。切换分支是因为之前我们通过docker安装的shardingproxy是4.0.1版本的，因为这个过程比较简单，我这里就不详细说明了。
zkui（可选）
为了方便的查看zookeeper中的信息，可以使用 zkui 这个工具来查看，github仓库：https://github.com/DeemOpen/zkui.git
下载代码，进入项目目录，执行mvn clean package生成 target/zkui-2.0-SNAPSHOT-jar-with-dependencies.jar，然后复制项目中的 config.cfg 与这个jar同一目录下，执行java -jar zkui-2.0-SNAPSHOT-jar-with-dependencies.jar ,打开页面9090，就可以看到zkui的界面了，用户名和密码默认是
用户名： admin
密码： manager
也可以直接使用zkClient.sh 查看：
[zk: localhost:2181(CONNECTED) 9] ls /orchestration/orchestration_ds
[config, state]当我们通过界面启用或者禁用某个DataSource的时候，zookeeper 会触发WatchedEvent
[zk: localhost:2181(CONNECTED) 18] ls /orchestration/orchestration_ds/state/datasources
[master_slave_db.ds_slave1, master_slave_db.ds_slave2]
WatchedEvent state:SyncConnected type:NodeDataChanged path:/orchestration/orchestration_ds/state/datasources/xxx在应用内会被org.apache.shardingsphere.orchestration.internal.registry.state.listener.DataSourceStateChangedListener 这个监听器监听到，然后会抛出一个应用内部的事件对象DisabledStateChangedEvent，用的是Guava的一个简单的事件订阅和发布的组件，然后应用内监听到这个事件后，会被带有注解com.google.common.eventbus.Subscribe 的方法处理，会将禁用的dataSource名称加入到MasterSlaveRule对象的禁用DataSource列表中，以后再执行查询时，就会排除掉这些已经被禁用的 SlaveNode。
master_slave_db.ds_slave1 这个名字其实分两部分组成，点前面的是 逻辑schema的名字，点后面的是dataSource的名字。
ShardingSphere Proxy Master Slave 这块有一些不太完善的地方，比如说，所有的slave都已经被DISABLED的情况下，会有除0异常（位置org/apache/shardingsphere/core/strategy/masterslave/RoundRobinMasterSlaveLoadBalanceAlgorithm.java:52），还有一个问题就是获取到某个DataSource之后，很有可能这个DataSource已经连不上了，但是状态并不是DISABLED，目前没有看到有自动DISABLED的逻辑。
我的想法是可以考虑获取一定频率的自动检测每个DataSource获取一个连接执行下isValid方法，如果无效就可以加入到DISABLED里面