1 簡介
Amoeba(變形蟲)項目是一個開源框架，於2008年開始發佈一款 Amoeba for Mysql軟件；這個軟件致力於MySQL的分佈式數據庫前端代理層，它主要在應用層訪問MySQL的時候充當SQL路由功能，專注於分佈式數據庫代理層（Database Proxy）開發；位於 Client、DB Server(s)之間,對客戶端透明；具有負載均衡、高可用性、SQL 過濾、讀寫分離、可路由相關的請求到目標數據庫、可併發請求多臺數據庫併合並結果；通過Amoeba你能夠完成多數據源的高可用、負載均衡、數據切片的功能，目前Amoeba已在很多企業的生產線上面使用；
2 環境準備
mysql使用原有一主兩從環境的四臺機器，主從環境保持不變
mysql主 192.168.0.201
mysql從 192.168.0.202
mysql從 192.168.0.203
amoeba 192.168.0.204
mysql具體環境安裝配置以及主從設置可以參考上一篇文章https://blog.51cto.com/superleedo/2419648
保持原有的一主兩從環境正常使用，下面內容主要是amoeba的部署配置及使用
3 amoeba的安裝配置
3.1 先安裝java
yum install java-1.8.0-openjdk* -y
[root@localhost ~]# java -version openjdk version "1.8.0_212" OpenJDK Runtime Environment (build 1.8.0_212-b04) OpenJDK 64-Bit Server VM (build 25.212-b04, mixed mode)
設置環境變量
export JAVA_HOME=/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.212.b04-0.el7_6.x86_64 正式環境請在/etc/profile 中聲明
3.2 安裝amoeba
下載安裝包
兩個地址選一個 wget https://sourceforge.net/projects/amoeba/files/Amoeba%20for%20mysql/3.x/amoeba-mysql-3.0.5-RC-distribution.zip wget https://jaist.dl.sourceforge.net/project/amoeba/Amoeba%20for%20mysql/3.x/amoeba-mysql-3.0.5-RC-distribution.zip
解壓amoeba包：
unzip amoeba-mysql-3.0.5-RC-distribution.zip cd amoeba-mysql-3.0.5-RC
創建數據庫授權用戶：
在master和salve數據庫中給amoeba授權一個mysql遠程賬戶（一主兩從都要創建賬戶）
mysql> GRANT ALL PRIVILEGES ON *.* TO 'amoeba'@'192.168.0.%' IDENTIFIED BY 'amoeba' WITH GRANT OPTION; mysql> flush privileges; 並在主庫上創建一個test數據庫，供默認連接使用 mysql> create database test; Query OK, 1 row affected (0.00 sec)
3.3 修改配置文件dbServers.xml和amoeba.xml
cd amoeba-mysql-3.0.5-RC/
修改 jvm.properties 根據自己機器內存大小調整 （調整-Xss爲512k，默認的太小了）
JVM_OPTIONS="-server -Xms256m -Xmx1024m -Xss512k -XX:PermSize=16m -XX:MaxPermSize=96m"
cd conf/
修改dbServers.xml
vim dbServers.xml
<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> ## master和slave的數據庫端口
<!-- mysql schema -->
<property name="schema">test</property> ##默認連接的數據庫，必須保持之前創建的有
<!-- mysql user -->
<property name="user">amoeba</property> ##授權的數據庫用戶
<property name="password">amoeba</property> ##授權的數據庫密碼
</factoryConfig>
<poolConfig class="com.meidusa.toolkit.common.poolable.PoolableObjectPool">
<property name="maxActive">500</property>
<property name="maxIdle">500</property>
<property name="minIdle">1</property>
<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="master" parent="abstractServer"> ##設置定義主機master
<factoryConfig>
<!-- mysql ip -->
<property name="ipAddress">192.168.0.201</property> ##master對應ip
</factoryConfig>
</dbServer>
<dbServer name="slave1" parent="abstractServer"> ##設置定義主機slave1
<factoryConfig>
<!-- mysql ip -->
<property name="ipAddress">192.168.0.202</property> ##slave1對應ip
</factoryConfig>
</dbServer>
<dbServer name="slave2" parent="abstractServer"> ##設置對應主機slave2
<factoryConfig>
<!-- mysql ip -->
<property name="ipAddress">192.168.0.203</property> ##slave2對應ip
</factoryConfig>
</dbServer>
<dbServer name="readservers" virtual="true"> ##設置只讀連接池readservers
<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">slave1,slave2</property> ##添加只讀主機
</poolConfig>
</dbServer>
---------------------
vim 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> ##默認amoeba的連接端口
<!-- bind ipAddress -->
<!--
<property name="ipAddress">127.0.0.1</property> ##amoeba 的本機ip
-->
<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">
<property name="user">root</property> ##設置連接8066端口的賬戶
<property name="password">123456</property> ##設置密碼
<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">master</property> ##設置默認連接服務器
<property name="writePool">master</property> ##設置寫服務器
<property name="readPool">readservers</property> #設置讀服務器，連接池
<property name="needParse">true</property>
</queryRouter>
</amoeba:configuration>
---------------------------------- 3.4 啓動amoeba
/home/amoeba-mysql-3.0.5-RC/bin/launcher > /var/log/amoeba.log 2>&1 &
3.5 連接amoeba 驗證能否創建查詢數據庫
[root@localhost amoeba-mysql-3.0.5-RC]# mysql -uroot -p123456 -h127.0.0.1 -P 8066 MySQL [(none)]> create database newtest; Query OK, 1 row affected (0.01 sec) MySQL [(none)]> show databases; +--------------------+ | Database | +--------------------+ | information_schema | | lili | | masu | | mysql | | newtest | | performance_schema | | sys | | test | | yan | +--------------------+ 9 rows in set (0.00 sec) 創建成功 MySQL [(none)]> use yan Reading table information for completion of table and column names You can turn off this feature to get a quicker startup with -A Database changed MySQL [yan]> select * from tom; +----+-----------+------+ | id | name | age | +----+-----------+------+ | 1 | zhangshan | 20 | | 2 | wangwu | 7 | | 3 | lisi | 23 | +----+-----------+------+ 3 rows in set (0.01 sec) -------------------------------------
3.6 從機器驗證讀的負載
先查看從機器Value 值 mysql202> show global status like 'Question%'; +---------------+-------+ | Variable_name | Value | +---------------+-------+ | Questions | 56 | +---------------+-------+ 1 row in set (0.01 sec) mysql203> show global status like 'Question%'; +---------------+-------+ | Variable_name | Value | +---------------+-------+ | Questions | 56 | +---------------+-------+ 1 row in set (0.01 sec) ameoba執行一次select * from tom; 查看slave機器查詢狀態 mysql202> show global status like 'Question%'; +---------------+-------+ | Variable_name | Value | +---------------+-------+ | Questions | 57 | +---------------+-------+ 1 row in set (0.00 sec) mysql203> show global status like 'Question%'; +---------------+-------+ | Variable_name | Value | +---------------+-------+ | Questions | 58 | +---------------+-------+ 1 row in set (0.01 sec) 顯然訪問的是203，步長爲2的即爲訪問的機器） 經驗證，ameoba再執行一次select * from tom; 202的 Value 值變爲59,203爲59,202的機器是查詢訪問機器。 由上面可知 讀的負載均衡也是成功的。 且主機器上沒有步長增加2，說明查詢命令都在slave機器上分發執行了，由此推測讀寫已經分離。 如果想驗證寫是否真正分離，可以將salve的同步停掉--slave stop 然後在ameoba上執行創建數據庫命令，回到三個數據庫機器驗證，查詢下是否只有主機器上有新數據庫。