Amoeba+Mysql實現數據庫讀寫分離

一、Amoeba 是什么

Amoeba(變形蟲)項目，專注 分布式數據庫 proxy 開發。座落與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query到目標數據庫、可並發請求多台數據庫合並結果。

主要解決：

• 降低 數據切分帶來的復雜多數據庫結構

• 提供切分規則並降低 數據切分規則 給應用帶來的影響

• 降低db 與客戶端的連接數

• 讀寫分離

 

二、為什么要用Amoeba

目前要實現mysql的主從讀寫分離，主要有以下幾種方案：

1、  通過程序實現，網上很多現成的代碼，比較復雜，如果添加從服務器要更改多台服務器的代碼。

2、  通過mysql-proxy來實現，由於mysql-proxy的主從讀寫分離是通過lua腳本來實現，目前lua的腳本的開發跟不上節奏，而寫沒有完美的現成的腳本，因此導致用於生產環境的話風險比較大，據網上很多人說mysql-proxy的性能不高。

3、  自己開發接口實現，這種方案門檻高，開發成本高，不是一般的小公司能承擔得起。

4、  利用阿里巴巴的開源項目Amoeba來實現，具有負載均衡、高可用性、sql過濾、讀寫分離、可路由相關的query到目標數據庫，並且安裝配置非常簡單。國產的開源軟件，應該支持，目前正在使用，不發表太多結論，一切等測試完再發表結論吧，哈哈！

 

三、Amoeba的安裝

先介紹下部署環境：

amoeba:192.168.2.203

masterDB：192.168.2.204 

slaveDB：192.168.2.205

以上系統全為centos6.8

 

Amoeba框架是居於JDK1.5開發的，采用了JDK1.5的特性，所以還需要安裝java環境，建議使用javaSE1.5以上的JDK版本

1、安裝java環境

先去官網下載：http://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html

安裝

[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...

然后設置java環境變量

[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

測試是否安裝成功

[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、安裝Amoeba

可以從https://sourceforge.net/projects/amoeba/下載最新版本的Amoeba，我這里下載的是amoeba-mysql-3.0.5-RC-distribution.zip。Amoeba安裝非常簡單，直接解壓即可使用，這里將Amoeba解壓到/usr/local/amoeba目錄下，這樣就安裝完成了

[root@bogon amoeba]# pwd
/usr/local/amoeba

  [root@bogon amoeba]# ll
  總用量 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的配置文件在本環境下位於/usr/local/amoeba/conf目錄下。配置文件比較多，但是僅僅使用讀寫分離功能，只需配置兩個文件即可，分別是dbServers.xml和amoeba.xml，如果需要配置ip訪問控制，還需要修改access_list.conf文件，下面首先介紹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>　　#設置Amoeba要連接的mysql數據庫的端口，默認是3306
            
            <!-- mysql schema -->
            <property name="schema">testdb</property>　　#設置缺省的數據庫，當連接amoeba時，操作表必須顯式的指定數據庫名，即采用dbname.tablename的方式，不支持 use dbname指定缺省庫，因為操作會調度到各個后端dbserver
            
            <!-- mysql user -->
            <property name="user">test1</property>　　#設置amoeba連接后端數據庫服務器的賬號和密碼，因此需要在所有后端數據庫上創建該用戶，並授權amoeba服務器可連接
            
            <property name="password">111111</property>
        </factoryConfig>

        <poolConfig class="com.meidusa.toolkit.common.poolable.PoolableObjectPool">
            <property name="maxActive">500</property>　　#最大連接數，默認500
            <property name="maxIdle">500</property>　　　　#最大空閑連接數
            <property name="minIdle">1</property>　　　　#最新空閑連接數
            <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">　　#設置一個后端可寫的dbServer，這里定義為writedb，這個名字可以任意命名，后面還會用到
        <factoryConfig>
            <!-- mysql ip -->
            <property name="ipAddress">192.168.2.204</property> #設置后端可寫dbserver
        </factoryConfig>
    </dbServer>
    
    <dbServer name="slave"  parent="abstractServer">　　#設置后端可讀dbserver
        <factoryConfig>
            <!-- mysql ip -->
            <property name="ipAddress">192.168.2.205</property>
        </factoryConfig>
    </dbServer>
    
    <dbServer name="myslave" virtual="true">　　#設置定義一個虛擬的dbserver，實際上相當於一個dbserver組，這里將可讀的數據庫ip統一放到一個組中，將這個組的名字命名為myslave
        <poolConfig class="com.meidusa.amoeba.server.MultipleServerPool">
            <!-- Load balancing strategy: 1=ROUNDROBIN , 2=WEIGHTBASED , 3=HA-->
            <property name="loadbalance">1</property>　　#選擇調度算法，1表示復制均衡，2表示權重，3表示HA， 這里選擇1
            
            <!-- Separated by commas,such as: server1,server2,server1 -->
            <property name="poolNames">slave</property>　　#myslave組成員
        </poolConfig>
    </dbServer>
        
</amoeba:dbServers>

 

另一個配置文件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>　　　　#設置amoeba監聽的端口，默認是8066
            
            <!-- bind ipAddress -->　　　　#下面配置監聽的接口，如果不設置，默認監聽所以的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">
                    

1. # 提供客戶端連接amoeba時需要使用這里設定的賬號 (這里的賬號密碼和amoeba連接后端數據庫服務器的密碼無關)

                    <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>　　#設置amoeba默認的池，這里設置為writedb
        
        
        <property name="writePool">writedb</property>　　#這兩個選項默認是注銷掉的，需要取消注釋，這里用來指定前面定義好的倆個讀寫池
        <property name="readPool">myslave</property>　　 #
        
        <property name="needParse">true</property>
    </queryRouter>
</amoeba:configuration>

4、在masterdb上創建數據庫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是否復制成功

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mydb               |
| mysql              |
| performance_schema |
| test               |
| testdb             |
+--------------------+
6 rows in set (0.00 sec)

分別在masterdb和slavedb上為amoedb授權

 

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)

啟動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.

報錯:

Error: Could not create the Java Virtual Machine.
Error: A fatal exception has occurred. Program will exit.

從錯誤文字上看，應該是由於stack size太小，導致JVM啟動失敗，要如何修改呢？
其實Amoeba已經考慮到這個問題，並將JVM參數配置寫在屬性文件里。現在，讓我們通過該屬性文件修改JVM參數。
修改jvm.properties文件JVM_OPTIONS參數。

[root@bogon amoeba]# vim /usr/local/amoeba/jvm.properties 
改成：JVM_OPTIONS="-server -Xms1024m -Xmx1024m -Xss256k -XX:PermSize=16m -XX:MaxPermSize=96m"
原為：JVM_OPTIONS="-server -Xms256m -Xmx1024m -Xss196k -XX:PermSize=16m -XX:MaxPermSize=96m"

再次啟動

[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啟動正常

 

5、測試

遠程登陸mysql客戶端通過指定amoeba配置文件中指定的用戶名、密碼、和端口以及amoeba服務器ip地址鏈接mysql數據庫

[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中創建表test並插入數據

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)

分別登陸masterdb和slavedb查看數據

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，然后在客戶端分別執行插入和查詢功能

masterdb：

　　[root@bogon ~]# service mysqld stop
　　Shutting down MySQL. SUCCESS!

客戶端：

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],拒絕連接
mysql> select * from test_table;
+------+----------+
| id   | password |
+------+----------+
|    1 | test1    |
+------+----------+
1 row in set (0.01 sec)

可以看到，關掉masterdb和寫入報錯，讀正常

開啟masterdb上的msyql 關閉slave上的mysql

masterdb：

[root@bogon ~]# service mysqld start
Starting MySQL.. SUCCESS! 

slavedb：

[root@localhost ~]# service mysqld stop
Shutting down MySQL. SUCCESS! 

客戶端再次嘗試

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，讀取失敗

 

開啟slavedb上的mysql，查看數據是否自動同步

slavedb:

[root@localhost ~]# service mysqld start
Starting MySQL... SUCCESS! 

客戶端：

mysql> select * from test_table;
+------+----------+
| id   | password |
+------+----------+
|    1 | test1    |
|    2 | test2    |
+------+----------+
2 rows in set (0.01 sec)

接着客戶端：

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，到此全部結束

 

注：關於mysql主從同步自行查看博主之前的主從同步筆記！

 

Amoeba主配置文件($AMOEBA_HOME/conf/amoeba.xml)，用來配置Amoeba服務的基本參數，如Amoeba主機地址、端口、認證方式、用於連接的用戶名、密碼、線程數、超時時間、其他配置文件的位置等。

數據庫服務器配置文件($AMOEBA_HOME/conf/dbServers.xml)，用來存儲和配置Amoeba所代理的數據庫服務器的信息，如:主機IP、端口、用戶名、密碼等。

切分規則配置文件($AMOEBA_HOME/conf/rule.xml)，用來配置切分規則。

數據庫函數配置文件($AMOEBA_HOME/conf/functionMap.xml)，用來配置數據庫函數的處理方法，Amoeba將使用該配置文件中的方法解析數據庫函數。

切分規則函數配置文件($AMOEBA_HOME/conf/ruleFunctionMap.xml)，用來配置切分規則中使用的用戶自定義函數的處理方法。

訪問規則配置文件($AMOEBA_HOME/conf/access_list.conf)，用來授權或禁止某些服務器IP訪問Amoeba。

日志規格配置文件($AMOEBA_HOME/conf/log4j.xml)，用來配置Amoeba輸出日志的級別和方式。