一、Amoeba 是什么
Amoeba(变形虫)项目，专注 分布式数据库 proxy 开发。座落与Client、DB Server(s)之间。对客户端透明。具有负载均衡、高可用性、sql过滤、读写分离、可路由相关的query到目标数据库、可并发请求多台数据库合并结果。
主要解决：
• 降低 数据切分带来的复杂多数据库结构
• 提供切分规则并降低 数据切分规则 给应用带来的影响
• 降低db 与客户端的连接数
• 读写分离
二、为什么要用Amoeba
目前要实现mysql的主从读写分离，主要有以下几种方案：
1、 通过程序实现，网上很多现成的代码，比较复杂，如果添加从服务器要更改多台服务器的代码。
2、 通过mysql-proxy来实现，由于mysql-proxy的主从读写分离是通过lua脚本来实现，目前lua的脚本的开发跟不上节奏，而写没有完美的现成的脚本，因此导致用于生产环境的话风险比较大，据网上很多人说mysql-proxy的性能不高。
3、 自己开发接口实现，这种方案门槛高，开发成本高，不是一般的小公司能承担得起。
4、 利用阿里巴巴的开源项目Amoeba来实现，具有负载均衡、高可用性、sql过滤、读写分离、可路由相关的query到目标数据库，并且安装配置非常简单。国产的开源软件，应该支持，目前正在使用，不发表太多结论，一切等测试完再发表结论吧，哈哈！
三、Amoeba的安装
先介绍下部署环境：
amoeba:192.168.2.203
masterDB：192.168.2.204
slaveDB：192.168.2.205
以上系统全为centos6.8
Amoeba框架是居于JDK1.5开发的，采用了JDK1.5的特性，所以还需要安装java环境，建议使用javaSE1.5以上的JDK版本
1、安装java环境
先去官网下载：http://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html
安装
[root@bogon src]# rpm -ivh jdk-8u111-linux-x64.rpm Preparing... ########################################### [100%] 1:jdk1.8.0_111 ########################################### [100%] Unpacking JAR files... tools.jar... plugin.jar... javaws.jar... deploy.jar... rt.jar... jsse.jar... charsets.jar... localedata.jar...
然后设置java环境变量
[root@bogon src]# vim /etc/profile #set java environment JAVA_HOME=/usr/java/jdk1.8.0_111 JRE_HOME=/usr/java/jdk1.8.0_111/jre CLASS_PATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar:$JRE_HOME/lib PATH=$PATH:$JAVA_HOME/bin:$JRE_HOME/bin export JAVA_HOME JRE_HOME CLASS_PATH PATH
[root@bogon amoeba]# source /etc/profile
测试是否安装成功
[root@bogon src]# java -version java version "1.8.0_111" Java(TM) SE Runtime Environment (build 1.8.0_111-b14) Java HotSpot(TM) 64-Bit Server VM (build 25.111-b14, mixed mode)
2、安装Amoeba
可以从https://sourceforge.net/projects/amoeba/下载最新版本的Amoeba，我这里下载的是amoeba-mysql-3.0.5-RC-distribution.zip。Amoeba安装非常简单，直接解压即可使用，这里将Amoeba解压到/usr/local/amoeba目录下，这样就安装完成了
[root@bogon amoeba]# pwd /usr/local/amoeba
[root@bogon amoeba]# ll
总用量 20
drwxrwxrwx. 2 root root 4096 7月 5 2013 benchmark
drwxrwxrwx. 2 root root 4096 7月 5 2013 bin
drwxrwxrwx. 2 root root 4096 7月 5 2013 conf
-rwxrwxrwx. 1 root root 728 7月 5 2013 jvm.properties
drwxrwxrwx. 2 root root 4096 7月 5 2013 lib
3、配置Amoeba
Amoeba的配置文件在本环境下位于/usr/local/amoeba/conf目录下。配置文件比较多，但是仅仅使用读写分离功能，只需配置两个文件即可，分别是dbServers.xml和amoeba.xml，如果需要配置ip访问控制，还需要修改access_list.conf文件，下面首先介绍dbServers.xml
[root@bogon amoeba]# cat conf/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="connectionManager">${defaultManager}</property> <property name="sendBufferSize">64</property> <property name="receiveBufferSize">128</property> <!-- mysql port --> <property name="port">3306</property> #设置Amoeba要连接的mysql数据库的端口，默认是3306 <!-- mysql schema --> <property name="schema">testdb</property> #设置缺省的数据库，当连接amoeba时，操作表必须显式的指定数据库名，即采用dbname.tablename的方式，不支持 use dbname指定缺省库，因为操作会调度到各个后端dbserver <!-- mysql user --> <property name="user">test1</property> #设置amoeba连接后端数据库服务器的账号和密码，因此需要在所有后端数据库上创建该用户，并授权amoeba服务器可连接 <property name="password">111111</property> </factoryConfig> <poolConfig class="com.meidusa.toolkit.common.poolable.PoolableObjectPool"> <property name="maxActive">500</property> #最大连接数，默认500 <property name="maxIdle">500</property> #最大空闲连接数 <property name="minIdle">1</property> #最新空闲连接数 <property name="minEvictableIdleTimeMillis">600000</property> <property name="timeBetweenEvictionRunsMillis">600000</property> <property name="testOnBorrow">true</property> <property name="testOnReturn">true</property> <property name="testWhileIdle">true</property> </poolConfig> </dbServer> <dbServer name="writedb" parent="abstractServer"> #设置一个后端可写的dbServer，这里定义为writedb，这个名字可以任意命名，后面还会用到 <factoryConfig> <!-- mysql ip --> <property name="ipAddress">192.168.2.204</property> #设置后端可写dbserver </factoryConfig> </dbServer> <dbServer name="slave" parent="abstractServer"> #设置后端可读dbserver <factoryConfig> <!-- mysql ip --> <property name="ipAddress">192.168.2.205</property> </factoryConfig> </dbServer> <dbServer name="myslave" virtual="true"> #设置定义一个虚拟的dbserver，实际上相当于一个dbserver组，这里将可读的数据库ip统一放到一个组中，将这个组的名字命名为myslave <poolConfig class="com.meidusa.amoeba.server.MultipleServerPool"> <!-- Load balancing strategy: 1=ROUNDROBIN , 2=WEIGHTBASED , 3=HA--> <property name="loadbalance">1</property> #选择调度算法，1表示复制均衡，2表示权重，3表示HA， 这里选择1 <!-- Separated by commas,such as: server1,server2,server1 --> <property name="poolNames">slave</property> #myslave组成员 </poolConfig> </dbServer> </amoeba:dbServers>
另一个配置文件amoeba.xml
[root@bogon amoeba]# cat conf/amoeba.xml <?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.mysql.server.MySQLService"> <!-- port --> <property name="port">8066</property> #设置amoeba监听的端口，默认是8066 <!-- bind ipAddress --> #下面配置监听的接口，如果不设置，默认监听所以的IP <!-- <property name="ipAddress">127.0.0.1</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="authenticateProvider"> <bean class="com.meidusa.amoeba.mysql.server.MysqlClientAuthenticator">
- # 提供客户端连接amoeba时需要使用这里设定的账号 (这里的账号密码和amoeba连接后端数据库服务器的密码无关)
<property name="user">root</property>
<property name="password">123456</property> <property name="filter"> <bean class="com.meidusa.toolkit.net.authenticate.server.IPAccessController"> <property name="ipFile">${amoeba.home}/conf/access_list.conf</property> </bean> </property> </bean> </property> </service> <runtime class="com.meidusa.amoeba.mysql.context.MysqlRuntimeContext"> <!-- proxy server client process thread size --> <property name="executeThreadSize">128</property> <!-- per connection cache prepared statement size --> <property name="statementCacheSize">500</property> <!-- default charset --> <property name="serverCharset">utf8</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="defaultManager" class="com.meidusa.toolkit.net.MultiConnectionManagerWrapper"> <property name="subManagerClassName">com.meidusa.toolkit.net.AuthingableConnectionManager</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> <property name="defaultPool">writedb</property> #设置amoeba默认的池，这里设置为writedb <property name="writePool">writedb</property> #这两个选项默认是注销掉的，需要取消注释，这里用来指定前面定义好的俩个读写池 <property name="readPool">myslave</property> # <property name="needParse">true</property> </queryRouter> </amoeba:configuration>
4、在masterdb上创建数据库testdb
mysql> create database testdb; Query OK, 1 row affected (0.08 sec) mysql> show databases; +--------------------+ | Database | +--------------------+ | information_schema | | mydb | | mysql | | performance_schema | | test | | testdb | +--------------------+ 6 rows in set (0.00 sec)
查看slavedb是否复制成功
mysql> show databases; +--------------------+ | Database | +--------------------+ | information_schema | | mydb | | mysql | | performance_schema | | test | | testdb | +--------------------+ 6 rows in set (0.00 sec)
分别在masterdb和slavedb上为amoedb授权
mysql> GRANT ALL ON testdb.* TO 'test1'@'192.168.2.203' IDENTIFIED BY '111111'; Query OK, 0 rows affected (0.05 sec) mysql> flush privileges; Query OK, 0 rows affected (0.02 sec)
启动amoeba
[root@bogon amoeba]# /usr/local/amoeba/bin/launcher Error: JAVA_HOME environment variable is not set. [root@bogon amoeba]# vim /etc/profile^C [root@bogon amoeba]# source /etc/profile [root@bogon amoeba]# /usr/local/amoeba/bin/launcher Java HotSpot(TM) 64-Bit Server VM warning: ignoring option PermSize=16m; support was removed in 8.0 Java HotSpot(TM) 64-Bit Server VM warning: ignoring option MaxPermSize=96m; support was removed in 8.0 The stack size specified is too small, Specify at least 228k Error: Could not create the Java Virtual Machine. Error: A fatal exception has occurred. Program will exit.
报错:
Error: Could not create the Java Virtual Machine.
Error: A fatal exception has occurred. Program will exit.
从错误文字上看，应该是由于stack size太小，导致JVM启动失败，要如何修改呢？
其实Amoeba已经考虑到这个问题，并将JVM参数配置写在属性文件里。现在，让我们通过该属性文件修改JVM参数。
修改jvm.properties文件JVM_OPTIONS参数。
[root@bogon amoeba]# vim /usr/local/amoeba/jvm.properties 改成：JVM_OPTIONS="-server -Xms1024m -Xmx1024m -Xss256k -XX:PermSize=16m -XX:MaxPermSize=96m" 原为：JVM_OPTIONS="-server -Xms256m -Xmx1024m -Xss196k -XX:PermSize=16m -XX:MaxPermSize=96m"
再次启动
[root@bogon ~]# /usr/local/amoeba/bin/launcher at org.codehaus.plexus.classworlds.launcher.Launcher.launchStandard(Launcher.java:329) at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:239) at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:409) at org.codehaus.classworlds.Launcher.mainWithExitCode(Launcher.java:127) at org.codehaus.classworlds.Launcher.main(Launcher.java:110) Caused by: com.meidusa.toolkit.common.bean.util.InitialisationException: default pool required!,defaultPool=writedb invalid at com.meidusa.amoeba.route.AbstractQueryRouter.init(AbstractQueryRouter.java:469) at com.meidusa.amoeba.context.ProxyRuntimeContext.initAllInitialisableBeans(ProxyRuntimeContext.java:337) ... 11 more 2016-10-24 18:46:37 [INFO] Project Name=Amoeba-MySQL, PID=1577 , System shutdown .... Java HotSpot(TM) 64-Bit Server VM warning: ignoring option PermSize=16m; support was removed in 8.0 Java HotSpot(TM) 64-Bit Server VM warning: ignoring option MaxPermSize=96m; support was removed in 8.0 2016-10-24 18:50:19 [INFO] Project Name=Amoeba-MySQL, PID=1602 , starting... log4j:WARN log4j config load completed from file:/usr/local/amoeba/conf/log4j.xml 2016-10-24 18:50:21,668 INFO context.MysqlRuntimeContext - Amoeba for Mysql current versoin=5.1.45-mysql-amoeba-proxy-3.0.4-BETA log4j:WARN ip access config load completed from file:/usr/local/amoeba/conf/access_list.conf 2016-10-24 18:50:22,852 INFO net.ServerableConnectionManager - Server listening on 0.0.0.0/0.0.0.0:8066.
查看端口
[root@bogon ~]# netstat -unlpt | grep java tcp 0 0 :::8066 :::* LISTEN 1602/java
由此可知Amoeba启动正常
5、测试
远程登陆mysql客户端通过指定amoeba配置文件中指定的用户名、密码、和端口以及amoeba服务器ip地址链接mysql数据库
[root@lys2 ~]# mysql -h192.168.2.203 -uroot -p -P8066 Enter password: Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 1364055863 Server version: 5.1.45-mysql-amoeba-proxy-3.0.4-BETA Source distribution 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>
在testdb中创建表test并插入数据
mysql> use testdb; Database changed mysql> create table test_table(id int,password varchar(40) not null); Query OK, 0 rows affected (0.19 sec) mysql> show tables; +------------------+ | Tables_in_testdb | +------------------+ | test_table | +------------------+ 1 row in set (0.02 sec) mysql> insert into test_table(id,password) values('1','test1'); Query OK, 1 row affected (0.04 sec) mysql> select * from test_table; +------+----------+ | id | password | +------+----------+ | 1 | test1 | +------+----------+ 1 row in set (0.02 sec)
分别登陆masterdb和slavedb查看数据
masterdb：
mysql> use testdb; Database changed mysql> show tables; +------------------+ | Tables_in_testdb | +------------------+ | test_table | +------------------+ 1 row in set (0.00 sec) mysql> select * from test_table; +------+----------+ | id | password | +------+----------+ | 1 | test1 | +------+----------+ 1 row in set (0.03 sec)
slavedb：
mysql> use testdb; Database changed mysql> show tables; +------------------+ | Tables_in_testdb | +------------------+ | test_table | +------------------+ 1 row in set (0.00 sec) mysql> select * from test_table; +------+----------+ | id | password | +------+----------+ | 1 | test1 | +------+----------+ 1 row in set (0.00 sec)
停掉masterdb，然后在客户端分别执行插入和查询功能
masterdb：
[root@bogon ~]# service mysqld stop
Shutting down MySQL. SUCCESS!
客户端：
mysql> insert into test_table(id,password) values('2','test2'); ERROR 1044 (42000): Amoeba could not connect to MySQL server[192.168.2.204:3306],拒绝连接 mysql> select * from test_table; +------+----------+ | id | password | +------+----------+ | 1 | test1 | +------+----------+ 1 row in set (0.01 sec)
可以看到，关掉masterdb和写入报错，读正常
开启masterdb上的msyql 关闭slave上的mysql
masterdb：
[root@bogon ~]# service mysqld start
Starting MySQL.. SUCCESS!
slavedb：
[root@localhost ~]# service mysqld stop
Shutting down MySQL. SUCCESS!
客户端再次尝试
mysql> insert into test_table(id,password) values('2','test2'); Query OK, 1 row affected (0.19 sec) mysql> select * from test_table; ERROR 1044 (42000): poolName=myslave, no valid pools
可以看到插入成功，读取失败
开启slavedb上的mysql，查看数据是否自动同步
slavedb:
[root@localhost ~]# service mysqld start
Starting MySQL... SUCCESS!
客户端：
mysql> select * from test_table; +------+----------+ | id | password | +------+----------+ | 1 | test1 | | 2 | test2 | +------+----------+ 2 rows in set (0.01 sec)
接着客户端：
mysql> insert into test_table(id,password) values('3','test3'); Query OK, 1 row affected (0.03 sec) mysql> select * from test_table; +------+----------+ | id | password | +------+----------+ | 1 | test1 | | 2 | test2 | | 3 | test3 | +------+----------+ 3 rows in set (0.02 sec)
OK 一切正常，到此全部结束
注：关于mysql主从同步自行查看博主之前的主从同步笔记！
Amoeba主配置文件($AMOEBA_HOME/conf/amoeba.xml)，用来配置Amoeba服务的基本参数，如Amoeba主机地址、端口、认证方式、用于连接的用户名、密码、线程数、超时时间、其他配置文件的位置等。
数据库服务器配置文件($AMOEBA_HOME/conf/dbServers.xml)，用来存储和配置Amoeba所代理的数据库服务器的信息，如:主机IP、端口、用户名、密码等。
切分规则配置文件($AMOEBA_HOME/conf/rule.xml)，用来配置切分规则。
数据库函数配置文件($AMOEBA_HOME/conf/functionMap.xml)，用来配置数据库函数的处理方法，Amoeba将使用该配置文件中的方法解析数据库函数。
切分规则函数配置文件($AMOEBA_HOME/conf/ruleFunctionMap.xml)，用来配置切分规则中使用的用户自定义函数的处理方法。
访问规则配置文件($AMOEBA_HOME/conf/access_list.conf)，用来授权或禁止某些服务器IP访问Amoeba。
日志规格配置文件($AMOEBA_HOME/conf/log4j.xml)，用来配置Amoeba输出日志的级别和方式。
