mysql数据库读写分离
1. 读写分离
读写分离的前提需要数据库已经做好了主从同步，如何实现主从同步，可以参考：https://www.cnblogs.com/alamisu/p/11840749.html
为了实现读写分离，出现了很多解决方案，其中比较流行的是采用中间件做为Proxy，保持应用层代码不随数据库的变动而发生变化，这里包括Amoeba、Atlas、Cobar、Mycat、MySQL Proxy、MySQL Router等。
- 需要注意Amoeba管理的数据库服务器要能被访问；默认mysql服务器只监听127.0.0.1，也就是说mysql监听的端口需要设置成你需要的值，并且用来做远程登陆的用户需要被赋予对应的权限，否则amoeba无法访问数据库。
- 同时我们可以在数据库上创建不同用户，并赋予不同权限来使用数据库，实现读写分离。
2. 以Amoeba举例说明，主/从数据库服务器安装配置JDK环境，并且要求JDK至少1.7
下载安装JDK。需要主/从数据库服务器都安装配置JDK环境 # sudo wget --no-cookies --no-check-certificate --header "Cookie: gpw_e24=http%3A%2F%2Fwww.oracle.com%2F; oraclelicense=accept-securebackup-cookie" "http://download.oracle.com/otn-pub/java/jdk/8u141-b15/336fa29ff2bb4ef291e347e091f7f4a7/jdk-8u141-linux-x64.tar.gz"
# sudo mkdir /opt/JAVA
# sudo tar xf jdk-8u141-linux-x64.tar.gz -C /opt/JAVA
设置profile环境变量，将以下内容添加到/etc/profile末尾：
JAVA_HOME=/opt/JAVA/jdk1.8.0_141
CLASSPATH=$JAVA_HOME/lib/
PATH=$PATH:$JAVA_HOME/bin
export PATH JAVA_HOME CLASSPATH
# sudo source /etc/profile
# java -version
以下回显则表示成功：
3. 安装Amoeba
# sudo wget http://nchc.dl.sourceforge.net/project/amoeba/Amoeba%20for%20mysql/2.x/amoeba-mysql-binary-2.1.0-RC5.tar.gz
# sudo mkdir /usr/local/amoeba
# sudo tar xf amoeba-mysql-binary-2.1.0-RC5.tar.gz -C /usr/local/amoeba
切换至root用户，方便操作
# sudo su
# cd /usr/local/amoeba/bin/
修改 DEFAULT_OPTS="-server -Xms256m -Xmx256m -Xss128k" ---> DEFAULT_OPTS="-server -Xms256m -Xmx256m -Xss256k" ,否则会启动失败，报错如下
# ./amoeba
# cd /usr/local/amoeba/conf/
修改dbServers.xml
<?xml version="1.0" encoding="gbk"?> <!DOCTYPE amoeba:dbServers SYSTEM "dbserver.dtd"> <amoeba:dbServers xmlns:amoeba="http://amoeba.meidusa.com/"> <!-- Each dbServer needs to be configured into a Pool, If you need to configure multiple dbServer with load balancing that can be simplified by the following configuration: add attribute with name virtual = "true" in dbServer, but the configuration does not allow the element with name factoryConfig such as 'multiPool' dbServer --> <dbServer name="abstractServer" abstractive="true"> <factoryConfig class="com.meidusa.amoeba.mysql.net.MysqlServerConnectionFactory"> <property name="manager">${defaultManager}</property> <property name="sendBufferSize">64</property> <property name="receiveBufferSize">128</property> <!-- mysql port 数据库端口--> <property name="port">3306</property> <!-- mysql schema amoeba 需要访问的数据库表--> <property name="schema">test</property> <!-- mysql user 主从数据库分配给amoeba访问数据的用户--> <property name="user">root</property> <!-- mysql password 主从数据库分配给amoeba访问数据的密码--> <property name="password">123456</property> </factoryConfig> <poolConfig class="com.meidusa.amoeba.net.poolable.PoolableObjectPool"> <property name="maxActive">500</property> <property name="maxIdle">500</property> <property name="minIdle">10</property> <property name="minEvictableIdleTimeMillis">600000</property> <property name="timeBetweenEvictionRunsMillis">600000</property> <property name="testOnBorrow">true</property> <property name="testWhileIdle">true</property> </poolConfig> </dbServer> <dbServer name="master" parent="abstractServer"> <factoryConfig> <!-- mysql ip 主数据库地址--> <property name="ipAddress">10.100.0.249</property> </factoryConfig> </dbServer> <dbServer name="slave" parent="abstractServer"> <factoryConfig> <!-- mysql ip 从数据库地址，如果有多个从数据库需要重复多个DBServer模块--> <property name="ipAddress">10.100.0.147</property> </factoryConfig> </dbServer> <!-- 数据库池，虚拟服务器，实现读取的负载均衡，如果有多个Slave，则<property name="poolNames">slave1,slave2</property>用逗号隔开 --> <dbServer name="multiPool" virtual="true"> <poolConfig class="com.meidusa.amoeba.server.MultipleServerPool"> <!-- Load balancing strategy: 1=ROUNDROBIN , 2=WEIGHTBASED , 3=HA--> <property name="loadbalance">1</property> <!-- Separated by commas,such as: server1,server2,server1 --> <property name="poolNames">slave</property> </poolConfig> </dbServer> </amoeba:dbServers>
修改amoeba.xml，配置读写分离
<?xml version="1.0" encoding="gbk"?> <!DOCTYPE amoeba:configuration SYSTEM "amoeba.dtd"> <amoeba:configuration xmlns:amoeba="http://amoeba.meidusa.com/"> <proxy> <!-- service class must implements com.meidusa.amoeba.service.Service --> <service name="Amoeba for Mysql" class="com.meidusa.amoeba.net.ServerableConnectionManager"> <!-- port Amoeba 端口号 ，客户端client 链接amoeba端口号，不能和主从数据库冲突--> <property name="port">8066</property> <!-- bind ipAddress --> <!-- <property name="ipAddress">127.0.0.1</property> --> <property name="manager">${clientConnectioneManager}</property> <property name="connectionFactory"> <bean class="com.meidusa.amoeba.mysql.net.MysqlClientConnectionFactory"> <property name="sendBufferSize">128</property> <property name="receiveBufferSize">64</property> </bean> </property> <property name="authenticator"> <bean class="com.meidusa.amoeba.mysql.server.MysqlClientAuthenticator"> <!-- Amoeba 账号密码 ，客户端client 链接amoeba端 账号--> <property name="user">admin</property> <property name="password">123123</property> <property name="filter"> <bean class="com.meidusa.amoeba.server.IPAccessController"> <property name="ipFile">${amoeba.home}/conf/access_list.conf</property> </bean> </property> </bean> </property> </service> <!-- server class must implements com.meidusa.amoeba.service.Service --> <service name="Amoeba Monitor Server" class="com.meidusa.amoeba.monitor.MonitorServer"> <!-- port --> <!-- default value: random number <property name="port">9066</property> --> <!-- bind ipAddress --> <property name="ipAddress">127.0.0.1</property> <property name="daemon">true</property> <property name="manager">${clientConnectioneManager}</property> <property name="connectionFactory"> <bean class="com.meidusa.amoeba.monitor.net.MonitorClientConnectionFactory"></bean> </property> </service> <runtime class="com.meidusa.amoeba.mysql.context.MysqlRuntimeContext"> <!-- proxy server net IO Read thread size --> <property name="readThreadPoolSize">20</property> <!-- proxy server client process thread size --> <property name="clientSideThreadPoolSize">30</property> <!-- mysql server data packet process thread size --> <property name="serverSideThreadPoolSize">30</property> <!-- per connection cache prepared statement size --> <property name="statementCacheSize">500</property> <!-- query timeout( default: 60 second , TimeUnit:second) --> <property name="queryTimeout">60</property> </runtime> </proxy> <!-- Each ConnectionManager will start as thread manager responsible for the Connection IO read , Death Detection --> <connectionManagerList> <connectionManager name="clientConnectioneManager" class="com.meidusa.amoeba.net.MultiConnectionManagerWrapper"> <property name="subManagerClassName">com.meidusa.amoeba.net.ConnectionManager</property> <!-- default value is avaliable Processors <property name="processors">5</property> --> </connectionManager> <connectionManager name="defaultManager" class="com.meidusa.amoeba.net.MultiConnectionManagerWrapper"> <property name="subManagerClassName">com.meidusa.amoeba.net.AuthingableConnectionManager</property> <!-- default value is avaliable Processors <property name="processors">5</property> --> </connectionManager> </connectionManagerList> <!-- default using file loader --> <dbServerLoader class="com.meidusa.amoeba.context.DBServerConfigFileLoader"> <property name="configFile">${amoeba.home}/conf/dbServers.xml</property> </dbServerLoader> <queryRouter class="com.meidusa.amoeba.mysql.parser.MysqlQueryRouter"> <property name="ruleLoader"> <bean class="com.meidusa.amoeba.route.TableRuleFileLoader"> <property name="ruleFile">${amoeba.home}/conf/rule.xml</property> <property name="functionFile">${amoeba.home}/conf/ruleFunctionMap.xml</property> </bean> </property> <property name="sqlFunctionFile">${amoeba.home}/conf/functionMap.xml</property> <property name="LRUMapSize">1500</property> <!-- 默认数据库，主数据库 --> <property name="defaultPool">master</property> <!-- 写数据库 --> <property name="writePool">master</property> <!-- 读数据库，dbServer.xml 中配置的虚拟数据库，数据库池 --> <property name="readPool">slave</property> <property name="needParse">true</property> </queryRouter> </amoeba:configuration>
# cd /usr/local/amoeba/bin/
# ./amoeba start
4.然后就可以使用Amoeba客户端操作数据库了
使用Amoeba登陆数据库：
# mysql -h xxx.xxx.xxx.xxx -P 8066 -u admin -p # xxx.xxx.xxx.xxx 是amoeba服务端ip，8066是服务端口， admin是配置好的amoeba用户 最后再输入amoeba密码就可以登陆了
然后就可以按照数据库来执行操作了，Amoeba会根据配置好的信息来选择对应的数据库执行命令
